artisan cache:clear したらセッションがふっとんだ

現象

CACHE_DRIVERとSESSION_DRIVERをどちらもredisにしたうえで

$ php artisan cache:clear

したところセッションが消えてこまった

原因

CacheとSessionで使っているRedisのDBが同じだから

対策

Cache用のDBと、Session用のDBを分けてやればよい

具体例

config/database.php でセッション用のredisの接続を定義して
config/session.php でその接続を指定するようにしました

config/database.php

...
    /*
    |--------------------------------------------------------------------------
    | Redis Databases
    |--------------------------------------------------------------------------
    |
    | Redis is an open source, fast, and advanced key-value store that also
    | provides a richer set of commands than a typical key-value systems
    | such as APC or Memcached. Laravel makes it easy to dig right in.
    |
    */

    'redis' => [

        'client' => 'predis',

        'default' => [
            'host' => env('REDIS_HOST', '127.0.0.1'),
            'password' => env('REDIS_PASSWORD', null),
            'port' => env('REDIS_PORT', 6379),
            'database' => 0,
        ],

        'session' => [
            'host' => env('REDIS_HOST', '127.0.0.1'),
            'password' => env('REDIS_PASSWORD', null),
            'port' => env('REDIS_PORT', 6379),
            'database' => 1,
        ],

    ],
...

config/session.php

...
    /*
    |--------------------------------------------------------------------------
    | Session Database Connection
    |--------------------------------------------------------------------------
    |
    | When using the "database" or "redis" session drivers, you may specify a
    | connection that should be used to manage these sessions. This should
    | correspond to a connection in your database configuration options.
    |
    */

    'connection' => 'session',
...