PH63769: MQ Z/OS: ABN= 0C4-00000011 IN CSQ5MGX0

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• At normal queue manager shutdown the following 0C4 abend occurs
  when the queue manager is disconnecting from the CF structures:
  IEA794I SVC DUMP HAS CAPTURED: DUMPID=010 REQUESTED BY JOB
  (CSQ1MSTR) DUMP TITLE=CSQ1,ABN=
  0C4-00000011,C=MQ900.930.DB2M,M=CSQ5MFRR,P SW=070C0000AFEC7170
  DUMP CAPTURED USING OPTIMIZE=YES The S0C4 abend occurred in
  CSQ5MGX0 during QMGR shutdown. CSQ5MGX0 is driven for the QSG
  XCF MSGEXIT, which a QSG uses for sending kiss-and-tell messages
  to notify other QMGRs that shared state has changed. The root
  cause of the abend is a timing window when the DXWB quick cell
  storage pool is expanded by a QMGR service task, and then an XCF
  message is received by the QMGR during shutdown after the
  service task has been detached and has been through end of task
  processing.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 3 Modification 0 and Release 4       *
  *                 Modification 0.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Abend 0C4 occurs during queue manager   *
  *                      shutdown of a queue manager in a queue  *
  *                      sharing group.                          *
  ****************************************************************
  While processing XCF notifications sent from other queue
  managers in the QSG (for example, due to triggering), the QPHB
  for DXWB control blocks was expanded. In some scenarios, the new
  extent of the QPHB can be owned by a queue manager task (for
  example the IGQ Agent task) rather than the job step task. When
  the queue manager is subsequently shutdown, there is a timing
  window between the owning task ending (causing the storage to be
  freed) and the queue manager completing shutdown. If a
  notification arrives during this window, an attempt can be made
  to reference the now-freed storage, leading to the reported
  abend.
  

Problem conclusion

• The new extent of the QPHB is now owned by the queue manager job
  step task.
  

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:

  UO05376 UO05377

Modules/Macros

• CSQEWCMQ
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R300 PSY UO05377

     UP25/11/12 P F511

• R400 PSY UO05376

     UP25/11/12 P F511

Fix is available

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