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PI40139: MQGET OF NON-PERSISTENT MESSAGE INCORRECTLY BACKED OUT DURING PEER LEVEL RECOVERY FOLLOWING LOSS OF CONNECTIVITY

A fix is available

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APAR status

  • Closed as program error.

Error description

  • MQGET of non-persistent message incorrectly backed out during
    peer level recovery following loss of connectivity
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
    *                 Release 1 Modification 0.                    *
    ****************************************************************
    * PROBLEM DESCRIPTION: If connection is lost to the CF during  *
    *                      a get of a non-persistent message from  *
    *                      a shared queue with                     *
    *                      MQGMO_SYNCPOINT_IF_PERSISTENT then the  *
    *                      got message may unexpectedly still be   *
    *                      on the queue.                           *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    When a MQGET is performed for a non-persistent message from a
    shared queue, the get processing calls CSQESYNC to commit the
    in-progress get. However if connection is lost to the coupling
    facility during this processing, the message may be returned and
    also backed out from the uncommitted queue, returning the
    message to the queue, resulting in the message being possibly
    duplicated.
    

Problem conclusion

  • CSQESYNC processing has been updated to correct this scenario,
    to not return the message in this case, when connectivity is
    lost to the CF. This ensures the message will be correctly
    backed off the uncommitted queue when connectivity is restored
    to the CF. This ensures the message is not duplicated, and is
    not returned more than once.
    100Y
    CSQESYNC
    CSQIMGES
    

Temporary fix

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

Comments

APAR Information

  • APAR number

    PI40139

  • Reported component name

    WMQ Z/OS V7

  • Reported component ID

    5655R3600

  • Reported release

    100

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2015-05-01

  • Closed date

    2016-04-26

  • Last modified date

    2016-06-02

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

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

    UI37324

Modules/Macros

  • CSQESYNC CSQIMGES
    

Fix information

  • Fixed component name

    WMQ Z/OS V7

  • Fixed component ID

    5655R3600

Applicable component levels

  • R100 PSY UI37324

       UP16/05/26 P F605 Ž

Fix is available

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Document Information

Modified date:
02 June 2016