PM99531: WMQ Z/OS: MQGET HUNG DURING CONVERSION PROCESS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Multiple application threads (WMB for example) getting messages
  from a queue that require the same data conversion and the
  conversion table is not available can leave one of the threads
  hanging forever. When the hanging thread is cancelled the
  message is rolled back to the input queue.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of WebSphere MQ Version 7          *
  *                 Release 0 Modification 1 and                 *
  *                 Release 1 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: Application threads hang during MQGET   *
  *                      when they request the same data         *
  *                      conversion (same from/to CCSIDs) and    *
  *                      the conversion table is not available.  *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  In the situation where multiple threads request the same data
  conversion table to be loaded simultaneously and the table is
  not available, it can happen that one or more of those threads
  are left waiting forever for the table to load due to a
  synchronization problem.
  

Problem conclusion

• The code has been changed to improve synchronization around
  loading conversion tables, ensuring that all threads waiting
  for the tables to load are resumed.
  010Y
  100Y
  CSQALOCT
  CSQMLOCT
  CSQXLOCT
  

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:

  UI12187 UI12188

Modules/Macros

• CSQALOCT CSQMLOCT CSQXLOCT
  

Fix information

• Fixed component name

  WMQ Z/OS V7

• Fixed component ID

  5655R3600

Applicable component levels

• R010 PSY UI12187

     UP13/11/20 P F311

• R100 PSY UI12188

     UP13/11/20 P F311

Fix is available

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