PH32757: MQ FOR Z/OS: ABEND5C6-00E50002 IN CSQMCPRH

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• An ABEND occurred with the following dump title:
  ABN=5C6-00E50002,U=SYSOPR,C=MQ900.910.CICS-CSQCECTX,
    M=CSQGFRCV,LOC=CSQMCGLM.CSQMCPRH
  
  Reason code 00E50002 means "UNLATCH REQUEST AND LATCH NOT OWNED
  BY REQUESTING EB".
  
  The latch was in the AMGS control block.
  
  The abend occurred for a thread for a CICS task, which was
  suspended in CSQCECTX. It was presumably waiting to obtain the
  AMGSLTCH along with many other address spaces/tasks. While it
  was suspended, the CICS job was cancelled causing ABEND33E.
  CSQCECTX's critical_prr got control but did not reestablish
  addressability to the AMGS before attempting to free the latch.
  This resulted in the 5C6-00E50002 abend. The code should also
  test whether the thread owns the latch before trying to free
  it.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 1 Modification 0 and Release 2       *
  *                 Modification 0.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: If, when multiple CICS systems          *
  *                      connected to a qmgr are shut down some  *
  *                      suffer delays and therefore a cancel is *
  *                      issued, an abend 5C6-00E50002 from      *
  *                      CSQCECTX may occur.                     *
  ****************************************************************
  The failing task was suspended in CSQCECTX, waiting on the
  AMGSLTCH latch being held by another CICS region. The cancel
  triggered the recovery routine in CSQCECTX which did not
  reestablish addressability to the AMGS before attempting to free
  the latch. Due to an incorrect latch address, the unlatch
  request determined that this EB did not hold the latch and
  issued the abend 5C6-00E50002.
  

Problem conclusion

• The recovery routine code has been updated to free the latch
  correctly.
  

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:

  UI74493 UI74494

Modules/Macros

• CSQCECTX CSQMCGEL
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R100 PSY UI74494

     UP21/03/25 P F103 ¢

• R200 PSY UI74493

     UP21/03/25 P F103 ¢

Fix is available

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