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PI23325: WEBSPHERE MQ, INCONSISTENT RESULT BETWEEN WMQ AND DB2 DURING 2 PHASE COMMIT VIA RRS.

A fix is available

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APAR status

  • Closed as unreproducible in next release.

Error description

  • The problem occurs when the first operation in a unit of work
    is non-persistent and involves a shared queue (in this case
    URID 0015EF4C6000 performed an in-syncpoint MQGET of a
    non-persistent shared queue message, followed by an
    in-syncpoint MQPUT of a persistent shared queue message). When
    the MQGET was issued, the queue-manager expressed persistent
    interest in the RRS UR. However, the queue-manager had not yet
    created a UR, and hence an incorrect value was stored in the
    persistent interest data associated with the queue-managers
    interest in the RRS UR (the interest data should contain the
    URID of the queue-manager UR). Therefore, when the
    queue-manager was restarted after the LPAR outage, the
    queue-manager performed resync processing with RRS (ATRIRNI
    calls), but as the persistent interest data returned was
    incorrect, URID 0015EF4C6000 was backed-out.
    
    
    Additional Symptom(s) Search Keyword(s): MQ, DB2, RRS, UR,
    integrity, inconsistent
    

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: Performing an in-syncpoint MQGET of a   *
    *                      non-persistent message from a shared    *
    *                      queue followed by a MQPUT of a          *
    *                      persistent message to a shared queue,   *
    *                      without a commit in-between may result  *
    *                      in an in-doubt unit of work being       *
    *                      created if an error occurs before a     *
    *                      commit can take place. This occurs when *
    *                      the application is linked using a RRS   *
    *                      stub.                                   *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    An in-syncpoint MQGET of a non-persistent message from a shared
    queue results in the queue manager registering persistent
    interest in a RRS UR. In this scenario a MQ UR is not started
    during the MQGET, this results in the persistent interest data
    being incorrectly set. During the MQPUT call, the MQ UR is
    started, but the persistent interest is not updated in the RRS
    UR. This can result in an inconsistent state during 2 phase
    commit processing in RRS, resulting in an indoubt UR.
    

Problem conclusion

Temporary fix

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

Comments

  • The code was changed to ensure the persistent interest data in
    the RRS UR is updated when the related MQ UR is started. This
    ensures the UR data is consistent and does not result in an
    indoubt UR.
    ×**** PE14/10/31 FIX IN ERROR. SEE APAR PI28769  FOR DESCRIPTION
    

APAR Information

  • APAR number

    PI23325

  • Reported component name

    WMQ Z/OS V7

  • Reported component ID

    5655R3600

  • Reported release

    010

  • Status

    CLOSED UR1

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2014-08-05

  • Closed date

    2014-09-24

  • Last modified date

    2014-11-07

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

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

    UI21631 UI21632

Modules/Macros

  • CSQIDLM1 CSQILOGS CSQILOG1 CSQIRRSI CSQI201M
    CSQMCBCK CSQMCCMT CSQ3BCK  CSQ3CMIT CSQ3ONLY CSQ3RRSR
    

Fix information

  • Fixed component name

    WMQ Z/OS V7

  • Fixed component ID

    5655R3600

Applicable component levels

  • R010 PSY UI21631

       UP14/10/17 P F410 Ž

  • R100 PSY UI21632

       UP14/10/17 P F410 Ž

Fix is available

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Document Information

Modified date:
07 November 2014