PH41876: WITHIN AN MQ QSG APPLICATIONS WAITING FOR MESSAGES MAY INVALIDLY BE RETURNED MQRC 2033 EVEN THOUGH MESSAGES ARE AVAILABLE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• MQ Development finds that MQ may invalidly determine, for a
  shared queue, that key range monitoring is active when actually
  it has not yet been turned on. For those MQ instances, if a
  list transition occurs, none will be seen for the queue GET is
  issued for. This results in only some MQ instances processing
  the messages, while the other queue managers are posted with
  MQRC 2033. This APAR intends to amend the code to ensure that
  key range monitoring is enabled for the queue to ensure that
  all MQ instances can participate in processing workload
  directed to the QSG.
  .
  Additional keywords:
  MQGET MQRC_NO_MSG_AVAILABLE
  

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 and                 *
  *                 Release 3 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: An application that is waiting on a     *
  *                      message to be put to a shared queue     *
  *                      incorrectly receives MQRC 2033 even     *
  *                      though there are messages available on  *
  *                      the queue.                              *
  ****************************************************************
  In some cases MQ can internally record key range monitoring as
  being active on a shared queue when it has not actually been
  turned on yet. This can lead to an application that is waiting
  on that queue receiving MQRC 2033 (MQRC_NO_MSG_AVAILABLE) even
  though there are messages available on the queue.
  

Problem conclusion

• The MQ code has been corrected so that the state of whether key
  range monitoring is active or not is correctly reflected in MQ
  to avoid its state being recorded inconsistently.
  

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:

  UI83143 UI83144 UI83145

Modules/Macros

• CSQMTRGS
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R100 PSY UI83145

     UP22/11/29 P F211

• R200 PSY UI83144

     UP22/11/29 P F211

• R300 PSY UI83143

     UP22/11/29 P F211

Fix is available

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