PH56304: A TIMING WINDOW WHEN CSQ2QCP0 OPENS ITS INPUT QUEUE AND FAILS WITH CERTAIN REASON CODES INCLUDING MQRC_OBJECT_IN_USE.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The 5C6-00F2003F abend in CSQ2QCP0 is occurring after receiving
  a reqresync request, because the internal QTE control block has
  the wrong state. The state was set incorrectly after an earlier
  MQOPEN of a bridge queue failed with MQRC_OBJECT_IN_USE. The
  MQOPEN failed because the queue was defined with NOSHARE so the
  open was done with MQOO_INPUT_EXCLUSIVE, which failed because
  the shared queue was open on another QMGR in the QSG. Had the
  MQOPEN have succeeded, then the QTE state would have been set
  correctly.
  
  The MQOPEN failing for the input queue would usually lead to
  the task ending gracefully, but there is a timing window where
  a request is queued to the CSQ2QCP0 task before the CSQ2004E
  message is issued which can result in the abend.
  
  This problem is similar to that seen in APAR PK74394/PK74530,
  but for a different class of MQOPEN failures.
  
  The root cause of the abend is a timing window when CSQ2QCP0
  opens its input queue and fails with certain reason codes
  including MQRC_OBJECT_IN_USE.
  

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: When using an IMS bridge queue in a     *
  *                      queue sharing group, after              *
  *                      restarting either IMS, a queue          *
  *                      manager or altering a bridge queue to   *
  *                      GET(ENABLED), an attempt to open the    *
  *                      bridge queue fails with MQRC 2042       *
  *                      (MQRC_OBJECT_IN_USE) followed by a      *
  *                      5C6-00F2003F abend.                     *
  ****************************************************************
  The code which handles return codes for failed attempts to open
  an IMS bridge queue doesn't handle a scenario where
  resynchronization with IMS is in progress when the queue open
  fails with MQRC 2042. As a result, the task is left in an
  unexpected state, leading to an abend.
  

Problem conclusion

• The code has been changed to finish synchronizing with IMS in
  the case that a failure to open a bridge queue occurs during the
  startup of the IMS bridge queue control 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:

  UI98413 UI98414

Modules/Macros

• CSQ2QCP0
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R300 PSY UI98414

     UP24/09/25 P F409

• R400 PSY UI98413

     UP24/09/25 P F409

Fix is available

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