PH08548: THE NUMBER OF CONCURRENT SUB JOBS RUNNING UNDER A TOP-LEVEL BATCH JOB MAY EXCEED THE CONFIGURED MAXIMUM

9.0.5.0: WebSphere Application Server traditional Version 9.0.5 Refresh Pack
9.0.5.1: WebSphere Application Server traditional Version 9.0.5 Fix Pack 1
9.0.5.2: WebSphere Application Server traditional Version 9.0.5 Fix Pack 2
8.5.5.17: WebSphere Application Server V8.5.5 Fix Pack 17
9.0.5.3: WebSphere Application Server traditional Version 9.0.5 Fix Pack 3
8.5.5.20: WebSphere Application Server V8.5.5.20
8.5.5.18: WebSphere Application Server V8.5.5 Fix Pack 18
8.5.5.19: WebSphere Application Server V8.5.5 Fix Pack 19
8.5.5.16: WebSphere Application Server V8.5.5 Fix Pack 16
8.5.5.21: WebSphere Application Server V8.5.5.21

APAR status

• Closed as program error.

Error description

• Even with com.ibm.ws.batch.parallel.MAXIMUM_CONCURRENT_SUBJOBS
  set to a value of 1, a WebSphere Application Server Batch
  top-level job was observed running more than one sub job
  concurrently.
  

Local fix

• Setting the WebSphere variable
  GRID_ENDPOINT_PJM_JOB_STATUS_WAIT_INTERVAL
  to a higher value on the endpoint servers may reduce the
  liklihood of hitting the window in which the code inadvertantly
  allows additional subjobs to be run
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server Java Batch                           *
  ****************************************************************
  * PROBLEM DESCRIPTION: The value of the                        *
  *                      com.ibm.ws.batch.parallel.MAXIMUM_CONCU *
  *                      RRENT_SUBJOBS property specifies the    *
  *                      maximum number of sub jobs that can     *
  *                      run concurrently.  However, a timing    *
  *                      issue can occur where this can be       *
  *                      exceeded.                               *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The top level job handles the submission and completion
  processing of sub jobs.  Only the number of subjobs specified
  by the com.ibm.ws.batch.parallel.MAXIMUM_CONCURRENT_SUBJOBS
  should be running at once.  However, a timing issue exists
  such that this could be exceeded.  There is a fallback type of
  check in place that is intended to handle the case where the
  top level job does not receive a notification that a subjob
  has completed.  Periodically, if the top level job sees that
  it has not received a notification in some time, it will query
  the sub job status.  If it sees that it is complete, it will
  release a job from the queue to start running.  If this check
  and release happens just at the right time while the job
  completes through the normal channel of communication, this is
  where the extra job can be submitted.
  

Problem conclusion

• A code update has been to synchronize the handling of missed
  notifications, such that an extra job beyond the specified
  concurrent sub jobs limit can no longer be submitted.
  
  The fix for this APAR is currently targeted for inclusion in
  fix pack 9.0.5.0 and 8.5.5.16  Please refer to the Recommended
  Updates page for delivery information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  WEBSPHERE FOR Z

• Fixed component ID

  5655I3500

Applicable component levels

• R850 PSY

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