PH38869: MQ Z/OS: IMS SHARED BRIDGE QUEUE IS NOT PROCESSED BY OTHER QUEUE MANAGERS WHEN STOP OTMA IS DONE ON ONE MEMBER OF THE QSG

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• An MQ IMS Bridge queue is defined with QSGDISP(SHARED).
  
  In the reported case, there are 3 queue managers (CSQ1, CSQ2,
  and CSQ3) in the Queue Sharing Group (QSG) group that run on 3
  separate LPARs. There is an IMS running on each of these LPARS.
  
  Under normal processing, all 3 queue managers have the queue
  open for input (IPPROCS is non-zero).  It is open for output
  only on queue manager CSQ1.
  
  When STOP OTMA is done on CSQ1, the shared queue should
  continue to be processed by CSQ2 and CSQ3.  Those two queue
  managers still have the queue open, but messages build up on
  the queue because the messages are not being processed.  The
  two queue managers are not notified that there are messages on
  the queue although CSQ1 knows there is a non-zero CURDEPTH.
  The messages start being processed again when OTMA is restarted
  for CSQ1.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 0 Modification 0, Release 1          *
  *                 Modification 0 and Release 2 Modification 0. *
  ****************************************************************
  * PROBLEM DESCRIPTION: When a shared IMS bridge queue is open  *
  *                      for input on more than one queue        *
  *                      manager, if the connection to IMS is    *
  *                      closed on one qmgr then messages on the *
  *                      bridge queue may not be processed by    *
  *                      the other queue managers leading to a   *
  *                      build up of messages on the queue.      *
  ****************************************************************
  A combination of a flag and a timer is used during the
  processing of IMS bridge queues. While messages are being
  processed by two queue managers, there is a circumstance
  whereby the timer on one queue manager can be cancelled while
  the flag for processing a specific queue is set off.
  This can happen when a resume occurs for the tpipe on this queue
  manager, for instance if a tpipe is started when it is already
  running. Messages on this bridge queue will no longer be
  processed by this queue manager.
  If the connection from the other queue manager to IMS goes down,
  then messages build up on the bridge queue.
  

Problem conclusion

• CSQ2QCP0 has been changed to correctly set the flag so that the
  bridge queue will be processed by other queue managers that have
  it open for input.
  

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:

  UI77164 UI77165 UI77166

Modules/Macros

• CSQ2QCP0
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R000 PSY UI77166

     UP21/09/29 P F109 ¢

• R100 PSY UI77165

     UP21/09/29 P F109 ¢

• R200 PSY UI77164

     UP21/09/29 P F109 ¢

Fix is available

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