ApsaraDB for POLARDB MySQL 8.0 互換版その 2 です。

今回は、バッファプールまわりの挙動を中心に確かめてみました。

前回の記事 : Alibaba Cloud の POLARDB を試してみる（１）MySQL 8.0 互換版起動編

※当初、PostgreSQL 11 互換版も試そうと思っていたのですが、長くなりそうだったので先送りしました。

確認する内容

プライマリノードでINSERTした直後、読み取り専用ノードのバッファプールにINSERTしたデータが反映されるか？
ノード再起動後に当該ノードのバッファプール上のデータは残っているか？
Switch Primary Node 実行時に各ノードのバッファプール上のデータは残っているか？
プライマリノードでUPDATE実行後、読み取り専用ノードのバッファプールに更新が反映されるか？

**結果だけ先に見たい方はこちら**

反映されない（Aurora と同じ）
消える（Aurora とは異なる）
新プライマリノードは昇格前のバッファプールが引き継がれ、降格した旧プライマリノードは消える（Aurora と同じ）
反映される（Aurora と同じ）

エンドポイントについて

バッファプールまわりの確認の前に、POLARDB MySQL 8.0 互換版の各種エンドポイントについて簡単に触れておきます。

前回の記事からリンクしている、

PolarDB Series (5): Session Read Consistency

にある通り、POLARDB MySQL 互換版には、以下のようなものがあります。

プライマリノードに接続するエンドポイント（プライマリエンドポイント）
- VPC 接続用がデフォルトで用意される。Public なエンドポイントはオプション
プロキシ（PolarProxy）経由で各ノードに接続するクラスタエンドポイント

Aurora とは違い、個別ノードに接続するためのエンドポイントは提供されないようです。

今回は、

プライマリエンドポイント（polarprimary）
デフォルト（読み書き可能）クラスタエンドポイント（polardefault）
読み取り専用クラスタエンドポイント（polarreadonly）

の 3 つのエンドポイントを用意して動作を確認しました。

**エンドポイント設定**

![polar11_01.png](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/123899/db793c6d-73e8-e502-efb3-d4b1c3300b23.png) ![polar11_02.png](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/123899/a883a8e6-a81a-5ac4-4387-52bf0357f355.png) ![polar11_03.png](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/123899/87fde9d5-7017-a0e5-5949-aecfd96c342c.png)

各エンドポイントのIPアドレス

[root@polartest ~]# ping polarprimary.mysql.polardb.rds.aliyuncs.com
PING polarprimary.mysql.polardb.rds.aliyuncs.com (10.0.0.200) 56(84) bytes of data.
64 bytes from 10.0.0.200 (10.0.0.200): icmp_seq=1 ttl=102 time=0.097 ms
64 bytes from 10.0.0.200 (10.0.0.200): icmp_seq=2 ttl=102 time=0.105 ms
64 bytes from 10.0.0.200 (10.0.0.200): icmp_seq=3 ttl=102 time=0.099 ms
64 bytes from 10.0.0.200 (10.0.0.200): icmp_seq=4 ttl=102 time=0.098 ms
^C
--- polarprimary.mysql.polardb.rds.aliyuncs.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3000ms
rtt min/avg/max/mdev = 0.097/0.099/0.105/0.012 ms
[root@polartest ~]# ping polardefault.rwlb.rds.aliyuncs.com
PING polardefault.rwlb.rds.aliyuncs.com (10.0.0.201) 56(84) bytes of data.
64 bytes from 10.0.0.201 (10.0.0.201): icmp_seq=1 ttl=102 time=0.103 ms
64 bytes from 10.0.0.201 (10.0.0.201): icmp_seq=2 ttl=102 time=0.118 ms
64 bytes from 10.0.0.201 (10.0.0.201): icmp_seq=3 ttl=102 time=0.113 ms
64 bytes from 10.0.0.201 (10.0.0.201): icmp_seq=4 ttl=102 time=0.105 ms
^C
--- polardefault.rwlb.rds.aliyuncs.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3000ms
rtt min/avg/max/mdev = 0.103/0.109/0.118/0.014 ms
[root@polartest ~]# ping polarreadonly.rwlb.rds.aliyuncs.com
PING polarreadonly.rwlb.rds.aliyuncs.com (10.0.0.202) 56(84) bytes of data.
64 bytes from 10.0.0.202 (10.0.0.202): icmp_seq=1 ttl=102 time=0.161 ms
64 bytes from 10.0.0.202 (10.0.0.202): icmp_seq=2 ttl=102 time=0.132 ms
64 bytes from 10.0.0.202 (10.0.0.202): icmp_seq=3 ttl=102 time=0.118 ms
64 bytes from 10.0.0.202 (10.0.0.202): icmp_seq=4 ttl=102 time=0.118 ms
^C
--- polarreadonly.rwlb.rds.aliyuncs.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3000ms
rtt min/avg/max/mdev = 0.118/0.132/0.161/0.019 ms

サーバ変数について

動作確認の前にサーバ変数を確認してみました。

プライマリエンドポイントで実行したSHOW VARIABLESの結果を記します。

**SHOW VARIABLES の結果（プライマリ）**

サーバ変数

mysql> SHOW VARIABLES;
+----------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Variable_name                                            | Value                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
+----------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| activate_all_roles_on_login                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| add_filter_hint_to_super_user_command                    | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| auto_generate_certs                                      | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| auto_increment_increment                                 | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| auto_increment_offset                                    | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| autocommit                                               | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| automatic_sp_privileges                                  | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| avoid_temporal_upgrade                                   | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| back_log                                                 | 3000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| basedir                                                  | /u01/polardb80_current/                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| big_tables                                               | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| bind_address                                             | 0.0.0.0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| binlog_cache_size                                        | 2097152                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| binlog_checksum                                          | CRC32                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| binlog_direct_non_transactional_updates                  | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| binlog_error_action                                      | ABORT_SERVER                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| binlog_expire_logs_seconds                               | 1209600                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| binlog_format                                            | ROW                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| binlog_group_commit_sync_delay                           | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| binlog_group_commit_sync_no_delay_count                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| binlog_gtid_simple_recovery                              | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| binlog_io_cache_size                                     | 16777216                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| binlog_max_flush_queue_time                              | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| binlog_order_commits                                     | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| binlog_row_image                                         | FULL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| binlog_row_metadata                                      | MINIMAL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| binlog_row_value_options                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| binlog_rows_query_log_events                             | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| binlog_stmt_cache_size                                   | 32768                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| binlog_transaction_dependency_history_size               | 25000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| binlog_transaction_dependency_tracking                   | COMMIT_ORDER                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| block_encryption_mode                                    | aes-128-ecb                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| bulk_insert_buffer_size                                  | 8388608                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| caching_sha2_password_auto_generate_rsa_keys             | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| caching_sha2_password_private_key_path                   | private_key.pem                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| caching_sha2_password_public_key_path                    | public_key.pem                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| character_set_client                                     | utf8mb4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| character_set_connection                                 | utf8mb4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| character_set_database                                   | utf8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| character_set_filesystem                                 | binary                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| character_set_results                                    | utf8mb4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| character_set_server                                     | utf8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| character_set_system                                     | utf8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| character_sets_dir                                       | /u01/polardb80_current/share/charsets/                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| check_proxy_users                                        | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| client_endpoint_ip                                       | 10.0.0.201                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| collation_connection                                     | utf8mb4_0900_ai_ci                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| collation_database                                       | utf8_general_ci                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| collation_server                                         | utf8_general_ci                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| completion_type                                          | NO_CHAIN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| concurrent_insert                                        | AUTO                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| connect_timeout                                          | 10                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| core_file                                                | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| cost_threshold_for_parallelism                           | 50000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| cte_max_recursion_depth                                  | 1000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| datadir                                                  | /674365-1/home/mysql/data/dbs/                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| default_authentication_plugin                            | mysql_native_password                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| default_collation_for_utf8mb4                            | utf8mb4_0900_ai_ci                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| default_password_lifetime                                | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| default_storage_engine                                   | InnoDB                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| default_tmp_storage_engine                               | InnoDB                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| default_week_format                                      | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| delay_key_write                                          | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| delayed_insert_limit                                     | 100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| delayed_insert_timeout                                   | 300                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| delayed_queue_size                                       | 1000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| disabled_storage_engines                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| disconnect_on_expired_password                           | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| div_precision_increment                                  | 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| end_markers_in_json                                      | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| enforce_gtid_consistency                                 | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| eq_range_index_dive_limit                                | 10                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| error_count                                              | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| event_scheduler                                          | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| expire_logs_days                                         | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| explicit_defaults_for_timestamp                          | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| external_user                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| fix_control                                              | oby_limit_optimize=on                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| flush                                                    | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| flush_time                                               | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| force_maximum_parallel_degree                            | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| force_parallel_mode                                      | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| foreign_key_checks                                       | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| ft_boolean_syntax                                        | + -><()~*:""&|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| ft_max_word_len                                          | 84                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| ft_min_word_len                                          | 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| ft_query_expansion_limit                                 | 20                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| ft_stopword_file                                         | (built-in)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| general_log                                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| general_log_file                                         | /home/mysql/log/mysql/general.log                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| group_concat_max_len                                     | 1024                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| gtid_executed                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| gtid_executed_compression_period                         | 1000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| gtid_mode                                                | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| gtid_next                                                | AUTOMATIC                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| gtid_owned                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| gtid_purged                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| have_compress                                            | YES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| have_dynamic_loading                                     | YES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| have_geometry                                            | YES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| have_openssl                                             | YES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| have_profiling                                           | YES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| have_query_cache                                         | NO                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| have_rtree_keys                                          | YES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| have_ssl                                                 | YES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| have_statement_timeout                                   | YES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| have_symlink                                             | DISABLED                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| histogram_generation_max_mem_size                        | 20000000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| host_cache_size                                          | 128                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| hostname                                                 | i41e01113.cloud.et135                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| identity                                                 | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| implicit_primary_key                                     | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| information_schema_stats_expiry                          | 86400                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| init_connect                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| init_file                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| init_slave                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| inner_schema_list                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| inner_user_list                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| innodb_adaptive_flushing                                 | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_adaptive_flushing_lwm                             | 10                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_adaptive_hash_index                               | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_adaptive_hash_index_parts                         | 8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_adaptive_max_sleep_delay                          | 150000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| innodb_api_bk_commit_interval                            | 5                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_api_disable_rowlock                               | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_api_enable_binlog                                 | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_api_enable_mdl                                    | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_api_trx_level                                     | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_autoextend_increment                              | 64                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_autoinc_lock_mode                                 | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_buffer_pool_chunk_size                            | 134217728                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| innodb_buffer_pool_dump_at_shutdown                      | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_buffer_pool_dump_now                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_buffer_pool_dump_pct                              | 25                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_buffer_pool_filename                              | ib_buffer_pool                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| innodb_buffer_pool_instances                             | 8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_buffer_pool_load_abort                            | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_buffer_pool_load_at_startup                       | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_buffer_pool_load_now                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_buffer_pool_size                                  | 12884901888                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| innodb_change_buffer_max_size                            | 25                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_change_buffering                                  | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_checksum_algorithm                                | crc32                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| innodb_cmp_per_index_enabled                             | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_commit_concurrency                                | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_compact_allocation                                | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_compression_failure_threshold_pct                 | 5                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_compression_level                                 | 6                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_compression_pad_pct_max                           | 50                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_concurrency_tickets                               | 5000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_data_file_path                                    | ibdata1:200M:autoextend                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| innodb_data_home_dir                                     | /674365-1/home/mysql/data/log                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| innodb_deadlock_detect                                   | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_dedicated_server                                  | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_default_row_format                                | dynamic                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| innodb_directories                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| innodb_disable_sort_file_cache                           | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_doublewrite                                       | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_fast_shutdown                                     | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_file_per_table                                    | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_fill_factor                                       | 100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_flush_log_at_timeout                              | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_flush_log_at_trx_commit                           | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_flush_method                                      | ALL_O_DIRECT                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| innodb_flush_neighbors                                   | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_flush_sync                                        | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_flushing_avg_loops                                | 30                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_force_load_corrupted                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_force_recovery                                    | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_fsync_threshold                                   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_ft_aux_table                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| innodb_ft_cache_size                                     | 8000000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| innodb_ft_enable_diag_print                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_ft_enable_stopword                                | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_ft_max_token_size                                 | 84                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_ft_min_token_size                                 | 3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_ft_num_word_optimize                              | 2000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_ft_result_cache_limit                             | 2000000000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| innodb_ft_server_stopword_table                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| innodb_ft_sort_pll_degree                                | 2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_ft_total_cache_size                               | 640000000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| innodb_ft_user_stopword_table                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| innodb_io_capacity                                       | 4000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_io_capacity_max                                   | 8000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_lock_sys_rec_partition                            | 64                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_lock_sys_table_partition                          | 64                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_lock_wait_timeout                                 | 50                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_log_buffer_size                                   | 33554432                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| innodb_log_checksums                                     | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_log_compressed_pages                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_log_file_size                                     | 1073741824                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| innodb_log_files_in_group                                | 2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_log_group_home_dir                                | /674365-1/home/mysql/data/log                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| innodb_log_optimize_ddl                                  | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_log_spin_cpu_abs_lwm                              | 80                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_log_spin_cpu_pct_hwm                              | 50                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_log_wait_for_flush_spin_hwm                       | 400                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_log_write_ahead_size                              | 4096                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_lru_scan_depth                                    | 2048                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_max_dirty_pages_pct                               | 60.000000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| innodb_max_dirty_pages_pct_lwm                           | 10.000000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| innodb_max_purge_lag                                     | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_max_purge_lag_delay                               | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_max_undo_log_size                                 | 1073741824                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| innodb_monitor_disable                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| innodb_monitor_enable                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| innodb_monitor_lock_nowait                               | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_monitor_reset                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| innodb_monitor_reset_all                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| innodb_numa_interleave                                   | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_old_blocks_pct                                    | 37                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_old_blocks_time                                   | 1000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_online_alter_log_max_size                         | 134217728                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| innodb_open_files                                        | 3000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_optimize_fulltext_only                            | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_page_cleaners                                     | 8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_page_size                                         | 16384                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| innodb_parallel_scan_estimate_max_pages                  | 128                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_polar_auto_arrange                                | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_polar_checkpoint_on_new_replica                   | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_polar_copy_page                                   | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_polar_copy_page_pool_size                         | 134217728                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| innodb_polar_empty_page_or_log_check                     | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_polar_fil_extend_batch                            | 100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_polar_fil_extend_delay                            | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_polar_inactive_slave_clear_all                    | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_polar_inactive_slave_clear_by_id                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_polar_io_latency_warning                          | 300000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| innodb_polar_io_merge_enabled                            | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_polar_keep_inactive_replica                       | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_polar_keep_inactive_standby                       | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_polar_kick_replica_max_delay                      | 18446744073709551614                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_polar_log_auto_purge                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_polar_log_file_extend_method                      | fallocate                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| innodb_polar_log_file_max_reuse                          | 8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_polar_log_force_parse                             | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_polar_log_max_checkpoint_files                    | 2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_polar_log_max_reserved_files_no_slave             | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_polar_log_wait_delay                              | 100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_polar_log_wait_loops                              | 10                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_polar_min_log_files_keep                          | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_polar_notify_reader_after_sync                    | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_polar_notify_replica_after_sync                   | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_polar_purge_lsn_point_in_time_recovery            | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_polar_purge_sys_delay_ms                          | 1000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_polar_repl_info_sync                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_polar_restore_old_version                         | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_primary_abort_ddl_wait_replica_timeout            | 3600                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_primary_accept_reconnect_max_log_delay            | 107374182400                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| innodb_primary_degrade_timeout                           | 5                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_primary_dml_max_delay_microsec                    | 10000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| innodb_primary_flush_max_lsn_lag                         | 1509949440                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| innodb_primary_log_write_before_erase_trx                | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_primary_purge_max_id_lag                          | 18446744073709551614                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_primary_purge_max_lsn_lag                         | 18446744073709551614                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_primary_sync_no_slave                             | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_primary_sync_slave                                | no_wait                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| innodb_primary_sync_slave_timeout                        | 10000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| innodb_print_all_deadlocks                               | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_print_ddl_logs                                    | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_purge_batch_size                                  | 300                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_purge_rseg_truncate_frequency                     | 128                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_purge_threads                                     | 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_random_read_ahead                                 | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_rds_buffer_pool_file_del                          | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_rds_cleaner_max_lru_time                          | 1000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| innodb_rds_page_cleaner_adaptive_sleep                   | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_read_ahead_threshold                              | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_read_io_threads                                   | 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_read_only                                         | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_read_view_max_recorded_num                        | 512                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_redo_log_encrypt                                  | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_replica_log_addr_heap_max_size                    | 67108864                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| innodb_replica_log_max_lag                               | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_replica_log_parse_buf_chunk_over_allocate         | 2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_replica_log_parse_buf_size                        | 1677721600                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| innodb_replica_promote_wait_log_done                     | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_replica_retry_page_read_times                     | 5                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_replica_retry_read_wait                           | 100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_replication_delay                                 | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_rollback_on_timeout                               | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_rollback_segments                                 | 128                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_slave_crash_on_hang                               | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_slave_log_apply_batch_size                        | 16777216                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| innodb_slave_log_apply_worker                            | 8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_slave_log_block_do_check                          | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_slave_log_hash_per_worker                         | 16                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_slave_log_parse_buf_chunk_size                    | 67108864                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| innodb_slave_log_read_buf_count                          | 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_slave_log_store_ack_point                         | after_write                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| innodb_slave_loose_view_check                            | disable                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| innodb_slave_max_cached_dummy_index                      | 64                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_slave_parallel_apply_low_addrs                    | 16                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_slave_purge_defer_timeout                         | 3600000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| innodb_slave_purge_method                                | 2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_slave_reset_table_space_recv_state                | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_slave_show_correct_autoinc                        | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_sort_buffer_size                                  | 1048576                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| innodb_spin_wait_delay                                   | 6                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_standby_force_upgrade                             | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_standby_full_apply_startup                        | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_standby_remove_prealloc_log                       | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_stats_auto_recalc                                 | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_stats_include_delete_marked                       | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_stats_method                                      | nulls_equal                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| innodb_stats_on_metadata                                 | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_stats_persistent                                  | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_stats_persistent_sample_pages                     | 20                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_stats_transient_sample_pages                      | 8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_status_output                                     | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_status_output_locks                               | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_strict_mode                                       | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_sync_array_size                                   | 16                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_sync_spin_loops                                   | 30                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_table_locks                                       | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| innodb_temp_data_file_path                               | /home/mysql/log/tmp/ibtmp1:12M:autoextend                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| innodb_temp_tablespaces_dir                              | /home/mysql/log/tmp                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_thread_concurrency                                | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_thread_sleep_delay                                | 10000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| innodb_tmpdir                                            | /674365-1/home/mysql/data/log                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| innodb_transaction_id                                    | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_undo_directory                                    | /674365-1/home/mysql/data/log                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| innodb_undo_log_encrypt                                  | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_undo_log_truncate                                 | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_undo_tablespaces                                  | 8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| innodb_use_native_aio                                    | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| innodb_version                                           | 8.0.13                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| innodb_write_io_threads                                  | 4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| insert_id                                                | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| interactive_timeout                                      | 7200                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| internal_tmp_disk_storage_engine                         | InnoDB                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| internal_tmp_mem_storage_engine                          | MEMORY                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| join_buffer_size                                         | 524288                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| keep_files_on_create                                     | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| key_buffer_size                                          | 8388608                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| key_cache_age_threshold                                  | 300                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| key_cache_block_size                                     | 1024                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| key_cache_division_limit                                 | 100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| keyring_operations                                       | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| kill_idle_transaction_timeout                            | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| large_files_support                                      | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| large_page_size                                          | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| large_pages                                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| last_insert_id                                           | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| lc_messages                                              | en_US                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| lc_messages_dir                                          | /u01/polardb80_current/share/                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| lc_time_names                                            | en_US                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| license                                                  | GPL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| local_infile                                             | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| lock_instance_mode                                       | LOCK_NON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| lock_wait_timeout                                        | 31536000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| locked_in_memory                                         | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| log_bin                                                  | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| log_bin_basename                                         | ../log/mysql-bin                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| log_bin_index                                            | /674365-1/home/mysql/data/log/master-log-bin.index                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| log_bin_trust_function_creators                          | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| log_bin_use_v1_row_events                                | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| log_error                                                | /home/mysql/log/mysql/master-error.log                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| log_error_services                                       | log_filter_internal; log_sink_internal                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| log_error_suppression_list                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| log_error_verbosity                                      | 3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| log_output                                               | TABLE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| log_queries_not_using_indexes                            | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| log_slave_updates                                        | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| log_slow_admin_statements                                | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| log_slow_slave_statements                                | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| log_statements_unsafe_for_binlog                         | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| log_throttle_queries_not_using_indexes                   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| log_timestamps                                           | SYSTEM                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| long_query_time                                          | 1.000000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| low_priority_updates                                     | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| lower_case_file_system                                   | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| lower_case_table_names                                   | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| maintain_max_connections                                 | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| maintain_user_list                                       | root,aurora,replicator                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| mandatory_roles                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| master_info_repository                                   | FILE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| master_verify_checksum                                   | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| max_allowed_packet                                       | 1073741824                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| max_binlog_cache_size                                    | 18446744073709547520                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| max_binlog_size                                          | 524288000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| max_binlog_stmt_cache_size                               | 18446744073709498368                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| max_connect_errors                                       | 100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| max_connections                                          | 5512                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| max_delayed_threads                                      | 20                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| max_digest_length                                        | 1024                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| max_error_count                                          | 64                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| max_execution_time                                       | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| max_heap_table_size                                      | 67108864                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| max_insert_delayed_threads                               | 20                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| max_join_size                                            | 18446744073709551615                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| max_length_for_sort_data                                 | 1024                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| max_parallel_degree                                      | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| max_parallel_workers                                     | 16                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| max_points_in_geometry                                   | 65536                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| max_prepared_stmt_count                                  | 16382                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| max_relay_log_size                                       | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| max_seeks_for_key                                        | 18446744073709500000                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| max_sort_length                                          | 1024                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| max_sp_recursion_depth                                   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| max_user_connections                                     | 5512                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| max_write_lock_count                                     | 102400                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| min_examined_row_limit                                   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| myisam_data_pointer_size                                 | 6                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| myisam_max_sort_file_size                                | 9223372036853727232                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| myisam_mmap_size                                         | 18446744073709551615                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| myisam_recover_options                                   | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| myisam_repair_threads                                    | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| myisam_sort_buffer_size                                  | 8388608                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| myisam_stats_method                                      | nulls_unequal                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| myisam_use_mmap                                          | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| mysql_native_password_proxy_users                        | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| mysqlx_bind_address                                      | *                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| mysqlx_connect_timeout                                   | 30                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| mysqlx_document_id_unique_prefix                         | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| mysqlx_idle_worker_thread_timeout                        | 60                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| mysqlx_interactive_timeout                               | 28800                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| mysqlx_max_allowed_packet                                | 67108864                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| mysqlx_max_connections                                   | 100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| mysqlx_min_worker_threads                                | 2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| mysqlx_port                                              | 33060                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| mysqlx_port_open_timeout                                 | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| mysqlx_read_timeout                                      | 30                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| mysqlx_socket                                            | /tmp/mysqlx.sock                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| mysqlx_ssl_ca                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| mysqlx_ssl_capath                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| mysqlx_ssl_cert                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| mysqlx_ssl_cipher                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| mysqlx_ssl_crl                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| mysqlx_ssl_crlpath                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| mysqlx_ssl_key                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| mysqlx_wait_timeout                                      | 28800                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| mysqlx_write_timeout                                     | 60                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| net_buffer_length                                        | 16384                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| net_compression_level                                    | 6                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| net_read_timeout                                         | 30                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| net_retry_count                                          | 10                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| net_write_timeout                                        | 60                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| new                                                      | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| ngram_token_size                                         | 2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| offline_mode                                             | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| old                                                      | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| old_alter_table                                          | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| open_files_limit                                         | 655350                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| opt_enable_rds_priv_strategy                             | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| opt_indexstat                                            | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| opt_readonly_trans_implicit_commit                       | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| opt_tablestat                                            | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| optimizer_prune_level                                    | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| optimizer_search_depth                                   | 62                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| optimizer_switch                                         | index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,duplicateweedout=on,subquery_materialization_cost_based=on,use_index_extensions=on,condition_fanout_filter=on,derived_merge=on,use_invisible_indexes=off,skip_scan=on,force_parallel_group_with_merge_sort=off |
| optimizer_trace                                          | enabled=off,one_line=off                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| optimizer_trace_features                                 | greedy_search=on,range_optimizer=on,dynamic_range=on,repeated_subselect=on                                                                                                                                                                                                                                                                                                                                                                                                                       |
| optimizer_trace_limit                                    | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| optimizer_trace_max_mem_size                             | 16384                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| optimizer_trace_offset                                   | -1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| original_commit_timestamp                                | 36028797018963968                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| parallel_partition_factor                                | 100                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| parser_max_mem_size                                      | 18446744073709551615                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| password_history                                         | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| password_require_current                                 | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| password_reuse_interval                                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_point_dbug_enabled                           | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| performance_point_enabled                                | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| performance_point_iostat_interval                        | 2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_point_iostat_volume_size                     | 10000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| performance_point_lock_rwlock_enabled                    | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| performance_schema                                       | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| performance_schema_accounts_size                         | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_digests_size                          | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_error_size                            | 4577                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| performance_schema_events_parallel_query_history_size    | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_events_stages_history_long_size       | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_events_stages_history_size            | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_events_statements_history_long_size   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_events_statements_history_size        | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_events_transactions_history_long_size | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_events_transactions_history_size      | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_events_waits_history_long_size        | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_events_waits_history_size             | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_hosts_size                            | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_cond_classes                      | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_cond_instances                    | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_digest_length                     | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_digest_sample_age                 | 60                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| performance_schema_max_file_classes                      | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_file_handles                      | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_file_instances                    | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_index_stat                        | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_memory_classes                    | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_metadata_locks                    | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_mutex_classes                     | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_mutex_instances                   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_parallel_operator_objects         | 1024                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| performance_schema_max_parallel_query_classes            | 3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_parallel_query_objects            | 4096                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| performance_schema_max_prepared_statements_instances     | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_program_instances                 | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_rwlock_classes                    | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_rwlock_instances                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_socket_classes                    | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_socket_instances                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_sql_text_length                   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_stage_classes                     | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_statement_classes                 | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_statement_stack                   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_table_handles                     | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_table_instances                   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_table_lock_stat                   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_thread_classes                    | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_max_thread_instances                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_session_connect_attrs_size            | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_setup_actors_size                     | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_setup_objects_size                    | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| performance_schema_users_size                            | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| persisted_globals_load                                   | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| pid_file                                                 | /home/mysql/log/tmp/mysql.pid                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| plugin_dir                                               | /u01/polardb80_current/lib/plugin/                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| polar_binlog_packet_size                                 | 1048576                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| polar_compressed_protocol                                | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| polar_csv_log_table_basedir                              | /home/mysql/log/mysql                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| polar_dump_binlog                                        | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| polar_enable_replica                                     | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| polar_enforce_storage_engine                             | INNODB                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| polar_io_thread_max_wait_time                            | 86400                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| polar_log_bin                                            | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| polar_log_packet_size                                    | 1048576                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| polar_max_slaves                                         | 128                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| polar_node_basedir                                       | /home/mysql/log/mysql                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| polar_persisted_system_basedir                           | /home/mysql/log/mysql                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| polar_reconnect_count                                    | 8640                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| polar_reconnect_sleep_time                               | 10000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| polar_recover_ignore_fail                                | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| polar_sock_recv_buf_size                                 | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| polar_sock_send_buf_size                                 | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| polar_temp_table_or_file_pbdname                         | 674365-1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| polarfs_host_id                                          | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| polarfs_pangu_prefix                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| polarfs_temp_pangu_prefix                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| port                                                     | 3020                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| preload_buffer_size                                      | 32768                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| primary_degrade_binlog_dump_timeout                      | 10                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| primary_fast_lookup                                      | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| profiling                                                | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| profiling_history_size                                   | 15                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| protocol_version                                         | 10                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| proxy_user                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| pseudo_slave_mode                                        | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| pseudo_thread_id                                         | 16787194                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| query_alloc_block_size                                   | 8192                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| query_memory_hard_limit                                  | 18446744073709551615                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| query_memory_soft_limit                                  | 3436183552                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| query_prealloc_size                                      | 8192                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| rand_seed1                                               | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| rand_seed2                                               | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| range_alloc_block_size                                   | 4096                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| range_optimizer_max_mem_size                             | 8388608                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| rbr_exec_mode                                            | STRICT                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| rds_audit_log_buffer_size                                | 167772160                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| rds_audit_log_connection_policy                          | ALL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| rds_audit_log_dir                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| rds_audit_log_enabled                                    | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| rds_audit_log_event_buffer_size                          | 2048                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| rds_audit_log_flush                                      | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| rds_audit_log_format                                     | PLAIN                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| rds_audit_log_policy                                     | ALL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| rds_audit_log_row_limit                                  | 200000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| rds_audit_log_skip                                       | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| rds_audit_log_statement_policy                           | ALL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| rds_audit_log_strategy                                   | ASYNCHRONOUS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| rds_audit_log_version                                    | MYSQL_V1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| rds_kill_connections                                     | 20                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| rds_kill_user_list                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| rds_push_lsn_default_interval                            | 10                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| rds_release_date                                         | 20191104                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| rds_result_skip_counter                                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| rds_set_connection_id_enabled                            | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| rds_version                                              | 13                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| read_buffer_size                                         | 131072                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| read_only                                                | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| read_rnd_buffer_size                                     | 262144                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| records_threshold_for_parallelism                        | 10000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| regexp_stack_limit                                       | 8000000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| regexp_time_limit                                        | 32                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| relay_log                                                | /home/mysql/log/mysql/slave-relay.log                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| relay_log_basename                                       | /home/mysql/log/mysql/slave-relay                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| relay_log_index                                          | /home/mysql/log/mysql/slave-relay-log.index                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| relay_log_info_file                                      | /home/mysql/log/mysql/slave-relay-log.info                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| relay_log_info_repository                                | FILE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| relay_log_purge                                          | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| relay_log_recovery                                       | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| relay_log_space_limit                                    | 21474836480                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| replica_lock_wait_timeout                                | 50                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| report_host                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| report_password                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| report_port                                              | 3020                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| report_user                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| require_secure_transport                                 | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| resultset_metadata                                       | FULL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| rotate_log_table                                         | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| rotate_log_table_last_name                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| rpl_read_size                                            | 8192                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| rpl_semi_sync_master_enabled                             | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| rpl_semi_sync_master_timeout                             | 10000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| rpl_semi_sync_master_trace_level                         | 32                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| rpl_semi_sync_master_wait_for_slave_count                | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| rpl_semi_sync_master_wait_no_slave                       | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| rpl_semi_sync_master_wait_point                          | AFTER_COMMIT                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| rpl_semi_sync_slave_enabled                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| rpl_semi_sync_slave_trace_level                          | 32                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| rpl_stop_slave_timeout                                   | 31536000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| schema_definition_cache                                  | 256                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| secure_file_priv                                         | NULL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| server_id                                                | 10134283                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| server_id_bits                                           | 32                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| server_uuid                                              | efd98935-0d91-11ea-bb45-506b4b1c274a                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| session_track_gtids                                      | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| session_track_lsn_change                                 | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| session_track_schema                                     | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| session_track_state_change                               | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| session_track_system_variables                           | time_zone,autocommit,character_set_client,character_set_results,character_set_connection                                                                                                                                                                                                                                                                                                                                                                                                         |
| session_track_transaction_info                           | STATE                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| sha256_password_auto_generate_rsa_keys                   | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| sha256_password_private_key_path                         | private_key.pem                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| sha256_password_proxy_users                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| sha256_password_public_key_path                          | public_key.pem                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| show_create_table_verbosity                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| show_ipk_info                                            | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| show_old_temporals                                       | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| skip_external_locking                                    | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| skip_name_resolve                                        | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| skip_networking                                          | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| skip_show_database                                       | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| slave_allow_batching                                     | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| slave_checkpoint_group                                   | 512                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| slave_checkpoint_period                                  | 300                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| slave_compressed_protocol                                | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| slave_exec_mode                                          | STRICT                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| slave_io_thread_max_wait_time                            | 86400                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| slave_load_tmpdir                                        | /home/mysql/log/tmp                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| slave_max_allowed_packet                                 | 1073741824                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| slave_max_expire_on_master_timeout                       | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| slave_net_timeout                                        | 60                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| slave_parallel_type                                      | LOGICAL_CLOCK                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| slave_parallel_workers                                   | 8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| slave_pending_jobs_size_max                              | 167772160                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| slave_preserve_commit_order                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| slave_rows_search_algorithms                             | INDEX_SCAN,HASH_SCAN                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| slave_skip_errors                                        | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| slave_sql_verify_checksum                                | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| slave_trans_sync_level                                   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| slave_transaction_retries                                | 10                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| slave_type_conversions                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| slow_launch_time                                         | 2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| slow_query_log                                           | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| slow_query_log_file                                      | /home/mysql/log/mysql/slow_query.log                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| socket                                                   | /home/mysql/log/tmp/mysql.sock                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| sort_buffer_size                                         | 1048576                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| sql_auto_is_null                                         | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| sql_big_selects                                          | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| sql_buffer_result                                        | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| sql_log_bin                                              | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| sql_log_off                                              | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| sql_mode                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| sql_notes                                                | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| sql_quote_show_create                                    | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| sql_require_primary_key                                  | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| sql_safe_updates                                         | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| sql_select_limit                                         | 18446744073709551615                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| sql_slave_skip_counter                                   | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| sql_warnings                                             | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| ssl_ca                                                   | ca.pem                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| ssl_capath                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| ssl_cert                                                 | server-cert.pem                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| ssl_cipher                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| ssl_crl                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| ssl_crlpath                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| ssl_fips_mode                                            | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| ssl_key                                                  | server-key.pem                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| stored_program_cache                                     | 256                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| stored_program_definition_cache                          | 256                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| super_read_only                                          | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| sync_binlog                                              | 1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| sync_master_info                                         | 10000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| sync_relay_log                                           | 10000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| sync_relay_log_info                                      | 10000                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| system_time_zone                                         | CST                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| table_definition_cache                                   | 16384                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| table_open_cache                                         | 16384                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| table_open_cache_instances                               | 32                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| tablespace_definition_cache                              | 256                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| temptable_max_ram                                        | 1073741824                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| thread_cache_size                                        | 256                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| thread_handling                                          | one-thread-per-connection                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| thread_stack                                             | 262144                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| time_zone                                                | SYSTEM                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| timestamp                                                | 1574475273.117658                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| tls_version                                              | TLSv1,TLSv1.1,TLSv1.2                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| tmp_table_size                                           | 2097152                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| tmpdir                                                   | /home/mysql/log/tmp                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| transaction_alloc_block_size                             | 8192                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| transaction_allow_batching                               | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| transaction_isolation                                    | READ-COMMITTED                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| transaction_prealloc_size                                | 4096                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| transaction_read_only                                    | OFF                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| transaction_write_set_extraction                         | XXHASH64                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| unique_checks                                            | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| updatable_views_with_limit                               | YES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| use_secondary_engine                                     | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| version                                                  | 8.0.13                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| version_comment                                          | Source distribution                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| version_compile_machine                                  | x86_64                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| version_compile_os                                       | Linux                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| version_compile_zlib                                     | 1.2.11                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| wait_timeout                                             | 86400                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| warning_count                                            | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| windowing_use_high_precision                             | ON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
+----------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
717 rows in set (0.01 sec)

バッファプールのサイズはメモリ 16GB に対して 12GB 程度なので MySQL としては常識的な設定値
ざっと見た感じで以下のような変数が追加されている（一部は ApsaraDB RDS for MySQL にも存在する模様）
- force_maximum_parallel_degree
- force_parallel_mode
- innodb_polar_で始まるもの
- innodb_primary_で始まるもの
- innodb_rds_で始まるもの
- innodb_replica_で始まるもの
- innodb_slave_で始まるもの
- max_parallel_degree
- parallel_partition_factor
- performance_point
- polar_で始まるもの
- polarfs_で始まるもの
- primary_degrade_binlog_dump_timeout
- primary_fast_lookup
- rds_で始まるもの

各クラスタエンドポイントからの接続先について

読み書き可能クラスタエンドポイントからの接続は、プライマリノード・読み取り専用ノードのそれぞれに動的に振り分けられるようです。
途中で更新系の SQL が実行された場合、その時点からプライマリノードに接続されるようです（先のリンク先に書かれている通り、設定に合わせた整合性確認が行われる模様）。

読み取り専用クラスタエンドポイントからの接続は、プライマリ以外の読み取り専用ノードに優先的に振り分けられるようです。

※SHOW VARIABLES LIKE 'innodb_read_only'で確認。hostname・server_id・server_uuidで接続先ノードを確認することも可能。

バッファプール関連の挙動

簡単なテーブルを用意し、データを 100 万行程度INSERTしておき、各種操作の後に全行読み込みの時間を確認することで、

メモリ（バッファプール）からの読み込み
ディスク（ストレージノード）からの読み込み

のどちらが行われたのかを確認（推測）しました。

**テーブル定義（プライマリノードで実行）**

テーブル定義

mysql> CREATE DATABASE bptest;
Query OK, 1 row affected (0.01 sec)

mysql> USE bptest;
Database changed
mysql> CREATE TABLE bptest (id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY, dummy_str1 VARCHAR(512) NOT NULL, val INT NOT NULL);
Query OK, 0 rows affected (0.57 sec)

**バッファプールにデータが載っているときの SELECT 実行時間**

バッファプールにデータが載っているときのSELECT実行時間

mysql> SELECT SUM(val) FROM bptest;
+----------+
| SUM(val) |
+----------+
|  1000000 |
+----------+
1 row in set (0.32 sec)

プライマリノードで`INSERT`した直後の読み取り専用ノード

ディスクからの読み込みになりました。当然と言えば当然です。

**プライマリノードで`INSERT`した直後の読み取り専用ノードで`SELECT`実行**

読み取り専用ノードでSELECT実行

mysql> SELECT SUM(val) FROM bptest;
+----------+
| SUM(val) |
+----------+
|  1000000 |
+----------+
1 row in set (12.03 sec)

ノード再起動後

ディスクからの読み込みとなりました。Aurora のような「DB を再起動してもバッファプールが維持される仕組み」は持たないようです。
なお、Aurora とは違い、ノードを再起動しても Primary / Read-only の切り替えは発生しないようです。

**プライマリノードで再起動後に`SELECT`実行**

プライマリノードでSELECT実行

mysql> SELECT SUM(val) FROM bptest;
ERROR 2013 (HY000): Lost connection to MySQL server during query
mysql> SELECT SUM(val) FROM bptest;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    96
Current database: bptest

+----------+
| SUM(val) |
+----------+
|  1000000 |
+----------+
1 row in set (11.07 sec)

Switch Primary Node 実行時

両ノードでSELECTを実行しバッファプールにデータが載っている状態で Switch Primary Node しました。

プライマリノードに昇格した側はバッファプールからの読み込みとなりました。
プライマリノードから降格した側はバッファプールが消えてディスクからの読み込みとなりました。

**Switch Primary Node**

![polar12_01.png](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/123899/f19e9f68-f96d-4d1d-96af-e327ebb27813.png) ![polar12_02.png](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/123899/baa696e1-5020-2bb4-b559-843bd0aa66fe.png) ※途中でクラスタを再作成したため、先のキャプチャとはエンドポイントやノードの ID が異なっています。

**Switch Primary Node 後にプライマリノードで`SELECT`実行**

プライマリノードでSELECT実行

mysql> SELECT SUM(val) FROM bptest;
ERROR 2013 (HY000): Lost connection to MySQL server during query
mysql> SELECT SUM(val) FROM bptest;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    1604
Current database: bptest

+----------+
| SUM(val) |
+----------+
|  1000000 |
+----------+
1 row in set (0.34 sec)

**Switch Primary Node 後に読み取り専用ノードで`SELECT`実行**

読み取り専用ノードでSELECT実行

mysql> SELECT SUM(val) FROM bptest;
ERROR 2013 (HY000): Lost connection to MySQL server during query
mysql> SELECT SUM(val) FROM bptest;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    1604
Current database: bptest

+----------+
| SUM(val) |
+----------+
|  1000000 |
+----------+
1 row in set (10.93 sec)

プライマリノードで`UPDATE`実行後の読み取り専用ノード

読み取り専用ノードですでにバッファプールに載っているデータに対し、プライマリノードでUPDATEしてみました。
結果、読み取り専用ノードでもバッファプールからの読み込みとなりました。
Aurora 同様、DB ノード間でバッファプールの整合性を保つための処理が実装されているようです。

**プライマリノードで`UPDATE`実行（読み書き可能クラスタエンドポイントより）**

プライマリノードでUPDATE実行

mysql> SHOW VARIABLES LIKE '%read_only';
+-----------------------+-------+
| Variable_name         | Value |
+-----------------------+-------+
| innodb_read_only      | ON    |
| read_only             | OFF   |
| super_read_only       | OFF   |
| transaction_read_only | OFF   |
+-----------------------+-------+
4 rows in set (0.02 sec)

※この時点では読み取り専用ノードに接続されている

mysql> SELECT SUM(val) FROM bptest;
+----------+
| SUM(val) |
+----------+
|  1000000 |
+----------+
1 row in set (0.37 sec)

mysql> UPDATE bptest SET val = 2;
Query OK, 1000000 rows affected (6.35 sec)

※接続先がプライマリノードに変更され、無事 UPDATE された 

mysql> SHOW VARIABLES LIKE '%read_only';
+-----------------------+-------+
| Variable_name         | Value |
+-----------------------+-------+
| innodb_read_only      | OFF   |
| read_only             | OFF   |
| super_read_only       | OFF   |
| transaction_read_only | OFF   |
+-----------------------+-------+
4 rows in set (0.00 sec)

**INSERT 直後の読み取り専用ノードで`SELECT`実行**

読み取り専用ノードでSELECT実行

mysql> SELECT SUM(val) FROM bptest;
+----------+
| SUM(val) |
+----------+
|  1000000 |
+----------+
1 row in set (10.24 sec)

※ここでプライマリノードに対し先の通り UPDATE 実行

mysql> SELECT SUM(val) FROM bptest;
+----------+
| SUM(val) |
+----------+
|  2000000 |
+----------+
1 row in set (0.32 sec)

参考：`SHOW ENGINE INNODB STATUS`について

プライマリエンドポイントで実行した結果を記します。

**`SHOW ENGINE INNODB STATUS`の結果**

InnoDBステータス

mysql> SHOW ENGINE INNODB STATUS\G
*************************** 1. row ***************************
  Type: InnoDB
  Name:
Status:
=====================================
2019-11-23 10:17:09 0x7f3758b39700 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 46 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 2290 srv_active, 0 srv_shutdown, 12 srv_idle
srv_master_thread log flush and writes: 0
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 5564
OS WAIT ARRAY INFO: reservation count 0
OS WAIT ARRAY INFO: reservation count 5068
OS WAIT ARRAY INFO: reservation count 0
OS WAIT ARRAY INFO: reservation count 5499
OS WAIT ARRAY INFO: reservation count 0
OS WAIT ARRAY INFO: reservation count 4970
OS WAIT ARRAY INFO: reservation count 0
OS WAIT ARRAY INFO: reservation count 5624
OS WAIT ARRAY INFO: reservation count 0
OS WAIT ARRAY INFO: reservation count 5130
OS WAIT ARRAY INFO: reservation count 0
OS WAIT ARRAY INFO: reservation count 5415
OS WAIT ARRAY INFO: reservation count 0
OS WAIT ARRAY INFO: reservation count 5126
OS WAIT ARRAY INFO: reservation count 0
OS WAIT ARRAY INFO: signal count 21161
RW-shared spins 3, rounds 6, OS waits 3
RW-excl spins 0, rounds 0, OS waits 0
RW-sx spins 0, rounds 0, OS waits 0
Spin rounds per wait: 2.00 RW-shared, 0.00 RW-excl, 0.00 RW-sx
------------
TRANSACTIONS
------------
Trx id counter 1989
Purge done for trx's n:o < 1988 undo n:o < 0 state: running but idle
History list length 1
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 421350604282336, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421350604281416, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421350604280496, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421350604279576, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421350604278656, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421350604277736, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421350604276816, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
--------
FILE I/O
--------
I/O thread 0 state: waiting for i/o request (insert buffer thread)
I/O thread 1 state: waiting for i/o request (log thread)
I/O thread 2 state: waiting for i/o request (read thread)
I/O thread 3 state: waiting for i/o request (read thread)
I/O thread 4 state: waiting for i/o request (read thread)
I/O thread 5 state: waiting for i/o request (read thread)
I/O thread 6 state: waiting for i/o request (write thread)
I/O thread 7 state: waiting for i/o request (write thread)
I/O thread 8 state: waiting for i/o request (write thread)
I/O thread 9 state: waiting for i/o request (write thread)
Pending normal aio reads: [0, 0, 0, 0] , aio writes: [0, 0, 0, 0] ,
 ibuf aio reads:, log i/o's:, sync i/o's:
Pending flushes (fsync) log: 0; buffer pool: 1
14362 OS file reads, 255159 OS file writes, 3378 OS fsyncs
5.85 reads/s, 1174 avg bytes/read, 132.37 writes/s, 1.48 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 0, seg size 2, 0 merges
merged operations:
 insert 0, delete mark 0, delete 0
discarded operations:
 insert 0, delete mark 0, delete 0
Hash table size 3187567, node heap has 2 buffer(s)
Hash table size 3187567, node heap has 2 buffer(s)
Hash table size 3187567, node heap has 3 buffer(s)
Hash table size 3187567, node heap has 0 buffer(s)
Hash table size 3187567, node heap has 0 buffer(s)
Hash table size 3187567, node heap has 0 buffer(s)
Hash table size 3187567, node heap has 2 buffer(s)
Hash table size 3187567, node heap has 3 buffer(s)
13.48 hash searches/s, 11.83 non-hash searches/s
---
LOG
---
Log sequence number          42318741
Log buffer assigned up to    42318741
Log buffer completed up to   42318741
Log written up to            42318741
Log flushed up to            42318741
Added dirty pages up to      42318741
Pages flushed up to          42318741
Last checkpoint at           42314975
246522 log i/o's done, 128.85 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 13359644672
Dictionary memory allocated 452734
Buffer pool size   786428
Free buffers       784407
Database pages     2009
Old database pages 0
Modified db pages  31
Pending reads      0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 1721, created 4857, written 3999
0.00 reads/s, 2.37 creates/s, 1.35 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 2009, unzip_LRU len: 0
I/O sum[496]:cur[0], unzip sum[0]:cur[0]
----------------------
INDIVIDUAL BUFFER POOL INFO
----------------------
---BUFFER POOL 0
Buffer pool size   98303
Free buffers       98053
Database pages     249
Old database pages 0
Modified db pages  0
Pending reads      0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 225, created 36, written 85
0.00 reads/s, 0.02 creates/s, 0.02 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 249, unzip_LRU len: 0
I/O sum[62]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 1
Buffer pool size   98303
Free buffers       98105
Database pages     196
Old database pages 0
Modified db pages  6
Pending reads      0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 181, created 21, written 846
0.00 reads/s, 0.00 creates/s, 0.26 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 196, unzip_LRU len: 0
I/O sum[62]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 2
Buffer pool size   98303
Free buffers       98096
Database pages     205
Old database pages 0
Modified db pages  6
Pending reads      0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 180, created 28, written 574
0.00 reads/s, 0.00 creates/s, 0.15 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 205, unzip_LRU len: 0
I/O sum[62]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 3
Buffer pool size   98303
Free buffers       98053
Database pages     248
Old database pages 0
Modified db pages  1
Pending reads      0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 229, created 397, written 86
0.00 reads/s, 2.35 creates/s, 0.04 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 248, unzip_LRU len: 0
I/O sum[62]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 4
Buffer pool size   98304
Free buffers       98088
Database pages     214
Old database pages 0
Modified db pages  0
Pending reads      0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 196, created 4152, written 170
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 214, unzip_LRU len: 0
I/O sum[62]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 5
Buffer pool size   98304
Free buffers       98025
Database pages     278
Old database pages 0
Modified db pages  9
Pending reads      0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 197, created 81, written 1027
0.00 reads/s, 0.00 creates/s, 0.43 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 278, unzip_LRU len: 0
I/O sum[62]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 6
Buffer pool size   98304
Free buffers       97942
Database pages     361
Old database pages 0
Modified db pages  9
Pending reads      0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 276, created 85, written 1085
0.00 reads/s, 0.00 creates/s, 0.41 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 361, unzip_LRU len: 0
I/O sum[62]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 7
Buffer pool size   98304
Free buffers       98045
Database pages     258
Old database pages 0
Modified db pages  0
Pending reads      0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 237, created 57, written 126
0.00 reads/s, 0.00 creates/s, 0.02 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 258, unzip_LRU len: 0
I/O sum[62]:cur[0], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Process ID=3928, Main thread ID=139860245473024 , state=sleeping
Number of rows inserted 3083045, updated 418, deleted 163, read 2058006
1474.51 inserts/s, 0.02 updates/s, 0.00 deletes/s, 956.91 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================

1 row in set (0.00 sec)

なお、読み書き可能なクラスタエンドポイントでは結果が表示され、読み取り専用のクラスタエンドポイントでは**Empty set**となりました。

参考：`SHOW PROCESSLIST`について

プライマリエンドポイントからの接続で実行するとプライマリノードの結果が返り、クラスタエンドポイントからの接続で実行すると複数ノードの結果が合成されるようです…が、処理が甘いのかエラーが出ていますね。

**プライマリエンドポイントから実行**

プライマリエンドポイントでのPROCESSLIST

mysql> SHOW PROCESSLIST;
+------+-----------------+----------------------+------+----------------+------+-------------------------+------------------+
| Id   | User            | Host                 | db   | Command        | Time | State                   | Info             |
+------+-----------------+----------------------+------+----------------+------+-------------------------+------------------+
|    4 | event_scheduler | localhost            | NULL | Daemon         | 3184 | Waiting on empty queue  | NULL             |
|   24 | root            | 127.0.0.1:59132      | NULL | Sleep          |    6 |                         | NULL             |
|   37 | root            | 127.0.0.1:59197      | NULL | Sleep          |    0 |                         | NULL             |
|   84 | root            | 127.0.0.1:59415      | NULL | Sleep          |    5 |                         | NULL             |
|  133 | root            | 127.0.0.1:59567      | NULL | Sleep          |   37 |                         | NULL             |
|  153 | replicator      | 11.198.20.195:44928  | NULL | Polar Log Dump |    0 | Reading log from innodb | NULL             |
|  154 | replicator      | 11.198.20.195:44929  | NULL | Polar Log Ack  |    0 | Receiving from client   | NULL             |
|  486 | replicator      | 11.194.242.232:51259 | NULL | Polar Log Dump |    0 | Reading log from innodb | NULL             |
|  488 | replicator      | 11.194.242.232:51261 | NULL | Polar Log Ack  |    0 | Receiving from client   | NULL             |
|  528 | aurora          | 11.112.240.32:54669  | NULL | Sleep          |    1 |                         | NULL             |
|  529 | aurora          | 11.112.239.96:42283  | NULL | Sleep          |    1 |                         | NULL             |
|  530 | aurora          | 11.112.240.32:54673  | NULL | RDS Push LSN   | 2881 | starting                | NULL             |
|  531 | aurora          | 11.112.239.96:42287  | NULL | RDS Push LSN   | 2881 | starting                | NULL             |
| 3316 | polaradmin      | 10.0.0.199:47360     | NULL | Query          |    0 | starting                | SHOW PROCESSLIST |
+------+-----------------+----------------------+------+----------------+------+-------------------------+------------------+
14 rows in set (0.00 sec)

**クラスタエンドポイントから実行**

クラスタエンドポイントでのPROCESSLIST

mysql> SHOW PROCESSLIST;
+----------+-----------------+----------------------+------+----------------+------+--------------------------------+------------------+
| Id       | User            | Host                 | db   | Command        | Time | State                          | Info             |
+----------+-----------------+----------------------+------+----------------+------+--------------------------------+------------------+
|        4 | event_scheduler | localhost            | NULL | Daemon         | 3589 | Waiting on empty queue         | NULL             |
|       24 | root            | 127.0.0.1:59132      | NULL | Sleep          |    1 |                                | NULL             |
|       37 | root            | 127.0.0.1:59197      | NULL | Sleep          |    0 |                                | NULL             |
|       84 | root            | 127.0.0.1:59415      | NULL | Sleep          |    0 |                                | NULL             |
|      133 | root            | 127.0.0.1:59567      | NULL | Sleep          |   22 |                                | NULL             |
|      153 | replicator      | 11.198.20.195:44928  | NULL | Polar Log Dump |    0 | Reading log from innodb        | NULL             |
|      154 | replicator      | 11.198.20.195:44929  | NULL | Polar Log Ack  |    0 | Receiving from client          | NULL             |
|      486 | replicator      | 11.194.242.232:51259 | NULL | Polar Log Dump |    0 | Reading log from innodb        | NULL             |
|      488 | replicator      | 11.194.242.232:51261 | NULL | Polar Log Ack  |    0 | Receiving from client          | NULL             |
|      528 | aurora          | 11.112.240.32:54669  | NULL | Sleep          |    1 |                                | NULL             |
|      529 | aurora          | 11.112.239.96:42283  | NULL | Sleep          |    1 |                                | NULL             |
|      530 | aurora          | 11.112.240.32:54673  | NULL | RDS Push LSN   | 3286 | starting                       | NULL             |
|      531 | aurora          | 11.112.239.96:42287  | NULL | RDS Push LSN   | 3286 | starting                       | NULL             |
|     3316 | polaradmin      | 10.0.0.199:47360     | NULL | Sleep          |  405 |                                | NULL             |
| 33575989 | polaradmin      | 10.0.0.199:40786     | NULL | Query          |    0 | starting                       | SHOW PROCESSLIST |
|        3 | system user     |                      | NULL | Connect        |    0 | Ack sender thread sending data | NULL             |
|        9 | root            | 127.0.0.1:54456      | NULL | Sleep          |    7 |                                | NULL             |
|       25 | root            | 127.0.0.1:54608      | NULL | Sleep          |   55 |                                | NULL             |
|       79 | root            | 127.0.0.1:55151      | NULL | Sleep          |    9 |                                | NULL             |
|       83 | root            | 127.0.0.1:55170      | NULL | Sleep          |    0 |                                | NULL             |
|      292 | aurora          | 11.112.240.32:22586  | NULL | Sleep          |    1 |                                | NULL             |
|      293 | aurora          | 11.112.239.96:28498  | NULL | Sleep          |    1 |                                | NULL             |
|      294 | aurora          | 11.112.240.32:22589  | NULL | RDS Push LSN   | 3286 | starting                       | NULL             |
|      295 | aurora          | 11.112.239.96:28504  | NULL | RDS Push LSN   | 3286 | starting                       | NULL             |
| 33575989 | polaradmin      | 10.0.0.199:40786     | NULL | Query          |    0 | starting                       | SHOW PROCESSLIST |
+----------+-----------------+----------------------+------+----------------+------+--------------------------------+------------------+
ERROR 2027 (HY000): Malformed packet
25 rows in set (0.00 sec)

…ところでRDS Push LSNしてるのは…お、auroraさん？

MySQLユーザ一覧

mysql> SELECT user, host FROM mysql.user;
+------------------+----------------+
| user             | host           |
+------------------+----------------+
| aurora           | %              |
| polaradmin       | %              |
| replicator       | %              |
| replicator       | 11.194.244.101 |
| replicator       | 11.198.18.167  |
| replicator       | 11.198.19.78   |
| root             | 127.0.0.1      |
| mysql.infoschema | localhost      |
| mysql.session    | localhost      |
| mysql.sys        | localhost      |
| root             | localhost      |
+------------------+----------------+
11 rows in set (0.00 sec)

mysql> SHOW GRANTS FOR `aurora`@`%`;
+----------------------------------------------------------------------------------------------------+
| Grants for aurora@%                                                                                |
+----------------------------------------------------------------------------------------------------+
| GRANT SELECT, RELOAD, PROCESS, SUPER, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO `aurora`@`%` |
| GRANT ALL PRIVILEGES ON `mysql`.* TO `aurora`@`%` WITH GRANT OPTION                                |
| GRANT ALL PRIVILEGES ON `test`.* TO `aurora`@`%` WITH GRANT OPTION                                 |
+----------------------------------------------------------------------------------------------------+
3 rows in set (0.00 sec)

次回以降、Advent Calendar 2019 （MySQL / PostgreSQL / alibabacloud）の記事として書いていく予定です。