PH51868: ABEND ABN=5C6-00D40016,U=XXXXXXXX,C=MQ900.920.MMC -CSQMCNA3,M=CSQGFRCV,LOC=CSQMLPLM.CSQMCNA3+00000A80

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Abend ABN=5C6-00D40016,U=XXXXXXXX,C=MQ900.920.MMC
  -CSQMCNA3,M=CSQGFRCV,LOC=CSQMLPLM.CSQMCNA3+00000A80 occurs when
  either an alter or a define replace command is issued for an
  existing qalias object. If the command results in the target
  queue being set to the same name as the qalias and the
  get(enabled/disabled) status is changed, CSQMCNA3 does not
  correctly track which locks have been obtained. This results in
  an attempt to free a lock twice, and MQ abends the task with
  5C6-00D40016.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 2 Modification 0 and                 *
  *                 Release 3 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: When altering or replacing an Alias     *
  *                      queue where the BaseQName is the same   *
  *                      as the Alias queue name and the Alias   *
  *                      queues InhibitGet attribute is swapped  *
  *                      between MQQA_GET_ALLOWED and            *
  *                      MQQA_GET_INHIBITED a 5C6-00D40016 abend *
  *                      is issued in the Queue Manager address  *
  *                      space.                                  *
  ****************************************************************
  When altering or replacing an Alias queue and the InhibitGet
  attribute is swapped between MQQA_GET_ALLOWED and
  MQQA_GET_INHIBITED a lock on the BaseQName is required so that
  any get wait applications that currently have the Base queue
  open can be cancelled.
  
  In the case where the BaseQName is the same as the Alias queue
  name, we already hold a lock on the name of the Alias queue name
  and hence will fail to get a lock on the BaseQName as we already
  have it. However, internally we track that we now hold 2 locks
  and during cleanup 2 attempts are made to release the locks.
  
  The second attempt to release the lock fails and issues the
  5C6-00D40016 abend.
  

Problem conclusion

• The code has been corrected so that in the case where the
  BaseQName is the same as the Alias queue name we will not
  attempt to get a lock on the BaseQName or try and release a lock
  that we do not have.
  

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:

  UI94307 UI94308

Modules/Macros

• CSQMCNA3
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R200 PSY UI94308

     UP23/11/15 P F311

• R300 PSY UI94307

     UP23/11/15 P F311

Fix is available

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