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Parallel asynchronous RFC

This example demonstrates parallel asynchronous RFC processing.

Other versions: 7.31 | 7.40 | 7.54

Source Code

    DATA: snd_jobs  TYPE i,
          exc_flag  TYPE i,
          indx      TYPE c LENGTH 4,
          name      TYPE c LENGTH 8.

    DATA(out) = cl_demo_output=>new( ).

    DO 10 TIMES.
      indx = sy-index.
      name = 'Task' && indx.
      CALL FUNCTION 'RFC_SYSTEM_INFO'
        STARTING NEW TASK name
        DESTINATION IN GROUP DEFAULT
        CALLING callbback_meth ON END OF TASK
        EXCEPTIONS
          system_failure        = 1 MESSAGE mess
          communication_failure = 2 MESSAGE mess
          resource_failure      = 3.
      CASE sy-subrc.
        WHEN 0.
          snd_jobs = snd_jobs + 1.
        WHEN 1 OR 2.
          out->write_text( mess ).
        WHEN 3.
          IF snd_jobs >= 1 AND
             exc_flag = 0.
             exc_flag = 1.
            WAIT UNTIL rcv_jobs >= snd_jobs
                 UP TO 5 SECONDS.
          ENDIF.
          IF sy-subrc = 0.
            exc_flag = 0.
          ELSE.
            out->display( 'Resource failure' ).
          ENDIF.
        WHEN OTHERS.
          out->display( 'Other error' ).
      ENDCASE.
    ENDDO.
    WAIT UNTIL rcv_jobs >= snd_jobs.
    out->display( task_list ).

Description

Parallel asynchronous processing of the function module RFC_SYSTEM_INFO using asynchronous remote function calls. Ten calls with different task IDsname are made, which each run in a separate work process. The callback routine callbback_meth counts the completed function modules and receives information about the target system.

The addition GROUP DEFAULT is used to distribute the execution among all application servers for the current system. If no further work process is available after at least one successful call, the system interrupts execution of the program until all function modules that have already been started have been completed. This interruption is limited to a maximum of five seconds.

After starting all function modules, the system waits until all callback routines have been executed. Then it outputs the internal table task_list it has filled. The output shows the sequence in which the individual tasks were completed and the application server each one was executed on.