qRFC is very useful way to call program many times chronologically. I've checked how to program and process types.

Strong points

Strong points of qRFC are as follows.

Process asynchronously
Process chronologically
When an error occurs, stop the queue and succeeding processes

The simplest program to use qRFC

The following program generates outbound queue. It's very simple!

Report YSIMPEST_QRFC

* Set an outbound queue name
  CALL FUNCTION 'TRFC_SET_QUEUE_NAME'
    EXPORTING
      qname              = 'YTEST01'
    EXCEPTIONS
      invalid_queue_name = 1
      OTHERS             = 2.
  IF sy-subrc <> 0.
    MESSAGE e001(00) WITH 'TRFC_SET_QUEUE_NAME error'.
  ENDIF.

* Call RFC module as qRFC
  CALL FUNCTION 'RFC_PING'
    IN BACKGROUND TASK
    AS SEPARATE UNIT.

  COMMIT WORK.
  IF sy-subrc <> 0.
    MESSAGE e001(00) WITH 'Commit error with return code:' sy-subrc.
  ENDIF.

3 ways to use qRFC

There are 3 ways to use qRFC. See the below picture.

Please see help portal page "qRFC Communication Model."

Type A: Outbound queue only

The following program uses outbound queue only.

REPORT YQRFC_OUTBOUND.

* Number of queues to be created
PARAMETERS p_queue TYPE i DEFAULT 1000.

START-OF-SELECTION.
  DO p_queue TIMES.

*   Set queue name
    CALL FUNCTION 'TRFC_SET_QUEUE_NAME'
      EXPORTING
        qname              = 'YTEST01'
      EXCEPTIONS
        invalid_queue_name = 1
        OTHERS             = 2.
    IF sy-subrc <> 0.
      MESSAGE e001(00) WITH 'Function TRFC_SET_QUEUE_NAME error'.
    ENDIF.

*   call as qRFC
    CALL FUNCTION 'RFC_PING'
      IN BACKGROUND TASK
      AS SEPARATE UNIT.

  ENDDO.

* Commit is necessary
  COMMIT WORK.
  IF sy-subrc <> 0.
    MESSAGE e001(00) WITH 'Commit error with sy-subrc:' sy-subrc.
  ENDIF.

Type B: Inbound queue only, Type C :Outbound and nbound queue

The below program generates only inbound queue or both outbound and inbound queue. When rfc destination is 'NONE' or omitted, it's type B.


REPORT  YQRFC_INBOUND.

PARAMETERS:
  p_num  TYPE i        DEFAULT 100,
  p_in   TYPE trfcqnam DEFAULT 'YTEST01_IN',
  p_out  TYPE trfcqnam DEFAULT 'YTEST01_OUT',
  p_rfc  TYPE rfcdest  DEFAULT 'NONE'.

START-OF-SELECTION.
  DO p_num TIMES.

    CALL FUNCTION 'TRFC_SET_QIN_PROPERTIES'
      EXPORTING
        qout_name          = p_out
        qin_name           = p_in
      EXCEPTIONS
        invalid_queue_name = 1
        OTHERS             = 2.
    IF sy-subrc <> 0.
      MESSAGE e001(00) WITH 'TRFC_SET_QIN_PROPERTIES error'.
    ENDIF.

    CALL FUNCTION 'RFC_PING'
      IN BACKGROUND TASK
      DESTINATION p_rfc
      AS SEPARATE UNIT.

  ENDDO.
  COMMIT WORK.
  IF sy-subrc <> 0.
    MESSAGE e001(00) WITH 'Commit error with return code:' sy-subrc.
  ENDIF.

As for type C, outbound queue is deleted when inbound queue is completely generated. The outbound queue's lifespan is not up to if inbound queue is finished or not.