PM99383: WMQ ABEND5C6 00C90900 IN CSQIMGE9 +00003620

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A failure occurs during publish processing (eg. queue full in
  which case messages will end up on the Dead Letter Queue).
  When CSQIMPUS ( or CSQIMPU2 ) detect the failure they will
  release all locks (including those for any previous messages
  put within the nested unit of work which may be messages
  intended for other subscribers). Since these locks are released
  these messages may be got even if they are actually not yet
  committed. Later, commit processing for publish completes and
  the get-cursor is updated to point to one of the messages that
  has been got. However, the page holding the message may have now
  been scavenged and used (as an example) for an IRHA. Then for
  the next MQGET against the queue the get-cursor is used to start
  searching for messages but as this points to an IRHA this abend
  results.
  .
  The above problem may also result in a 5C6-00C90B00 abend
  issued by CSQIMGE9.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
  *                 Release 0 Modification 1 and Release 1       *
  *                 Modification 0.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: A failure to deliver a publication to a *
  *                      subscriber's queue (for example, if the *
  *                      pageset or cfstruct is full) can cause  *
  *                      locks on messages put earlier in the    *
  *                      publish operation to be released        *
  *                      prematurely, leading to unpredictable   *
  *                      results.                                *
  *                                                              *
  *                      Observed symptoms can include:          *
  *                      - Uncommitted messages that were put    *
  *                        earlier in the same publish operation *
  *                        being returned on MQGET               *
  *                      - 5C6-00C90900 in CSQILPLM.CSQIMGE9     *
  *                      - 0C4 in CSQILPLM.CSQIKRCD              *
  *                      - Qmgr termination S6C6 REASON=00E50705 *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  While publishing to a topic with NPMSGDLV/PMSGDLV set to ALL or
  ALLDUR, a nested unit of work is started by CSQMTPUT.
  If an error occurs while putting to a subscriber queue,
  CSQLRELL is called to release all request locks acquired by the
  current put operation, however this call incorrectly releases
  locks relating to the put of messages to other subscribers by
  the same publish operation.
  Following this applications are able to get the messages put
  earlier in the publish operation prior to them being committed.
  This can lead to commit/abort processing referencing pages
  that have been deallocated and reused, leading to unpredictable
  results, including the reported abends.
  

Problem conclusion

• CSQLRELL is changed to only release request locks associated
  with the current request, when called within a nested unit of
  work (for example, a publish operation).
  010Y
  100Y
  CSQLGETL
  CSQLRELL
  CSQLRSAV
  CSQLSLKO
  CSQLSVTL
  CSQL1ALL
  CSQL1INI
  CSQL1RCL
  CSQL211M
  CSQWCBD
  CSQ7CBL
  CSQ7CBU
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

• ×**** PE14/05/08 FIX IN ERROR. SEE APAR PI14103  FOR DESCRIPTION
  

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UI14313 UI14314

Modules/Macros

• CSQLGETL CSQLRELL CSQLRSAV CSQLSLKO CSQLSVTL
  CSQL1ALL CSQL1INI CSQL1RCL CSQL211M CSQWCBD  CSQ7CBL  CSQ7CBU
  

Fix information

• Fixed component name

  WMQ Z/OS V7

• Fixed component ID

  5655R3600

Applicable component levels

• R010 PSY UI14313

     UP14/02/05 P F402 Ž

• R100 PSY UI14314

     UP14/02/05 P F402 Ž

Fix is available

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