PH08454: MQ Z/OS V9:ABN=5C6-00E50001,LOC=CSQELPLM.CSQEWCMQ+00000712

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Customer complained that one queue manager in queue sharing
  group took following abend:
  CSQA,ABN=5C6-00E50001,U=SYSOPR  ,
  -CSQEWCMQ,M=CSQGFRCV,LOC=CSQELPLM.CSQEWCMQ
  
  The abend occurred while resolving an indoubt QSG disposition
  unit of work, where the unit of work contained puts to a shared
  queue that were performed on a qmgr other than the one
  performing the resolve, and which is no longer running.
  CSQERRIN obtained a latch to serialise remote resolve
  processing, and called CSQERIND, which rebuilt the control
  blocks representing the uow operations. It then called CSQESYNC
  to commit the UOW. As part of this CSQEKATM was called to
  determine if the committed puts required any  other qmgrs to be
  notified (for example, due to triggering).
  However the IVSA pointer for the queue was not set, leading to
  these  checks being done using the contents of low core.
  Normally this results in it determining that no broadcast is
  required,  however in this instance, the values in low core
  caused CSQEWCMQ to be called to perform the notification - this
  requested the PCT latch, but as this has the same class as the
  remote resolve latch, a hierarchy violation was detected and
  the abend occurred.
  
  Additional Symptom(s) Search Keyword(s):
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 0 Modification 0 and Release 1       *
  *                 Modification 0.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Abend 5C6-00E50001 occurs in CSQEWCMQ   *
  *                      when an indoubt group unit of recovery  *
  *                      is resolved by committing the UR.       *
  ****************************************************************
  While committing an indoubt group unit of recovery for an
  inactive peer, CSQERIND calls CSQESYNC to commit any shared
  queue operations in the UR, while holding the remote resolve
  latch.
  CSQESYNC then calls CSQEKATM to check if any K&T notifications
  should be broadcast to other queue managers.
  However, the ivsa address is not available, leading to the
  notifications being generated based on values in low core.
  
  If any notifications are generated, CSQEWCMQ is called and
  attempts to get the PCT latch. However this latch conflicts
  with the remote resolve latch already held, leading to the
  reported latch hierarchy violation abend.
  

Problem conclusion

• CSQEKATM is changed to check if the IVSA address is set before
  using it to check if any notifications are required.
  

Temporary fix

Comments

APAR Information

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

  PI91842

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

  UI61532 UI61533

Modules/Macros

• CSQEKATM
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R000 PSY UI61532

     UP19/04/11 P F904

• R100 PSY UI61533

     UP19/04/11 P F904

Fix is available

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