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PI89764: WMQ 7.1: ABN=5C6-00940001 AND CSQX206E DUE TO INVALID SEQUENCE OF XA FLOWS FROM CLIENT.

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APAR status

  • Closed as program error.

Error description

  • abd 5c6 and CSQX206E caused by the XA client sending an invalid
    sequence of flows.
    
    The client is sending:
    
    xa_end() with TMFAIL
    
    followed by:
    
    xa_end() with TMSUCCESS
    
    This is invalid (for the same XID) as after the TMFAIL, the
    specification states that this:
    
    "dissociates caller and marks transaction branch rollback-only"
    
    However, despite this combination being invalid, MQ is not
    handling the exception in a graceful manner and that is why the
    abend is occurring.
    

Local fix

  • investigate the client application to determine the incorrect
    sequence of xa calls
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
    *                 Release 1 Modification 0                     *
    ****************************************************************
    * PROBLEM DESCRIPTION: Issuing multiple XA_END calls for the   *
    *                      same MQ XA transaction with the         *
    *                      CSQSERVICE1 flag set, results in abend  *
    *                      5C6-00940001 in CSQMCPRH.               *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    With CSQSERVICE1, XA transactions can be prepared on a different
    client connection. However with this, when a XA_END call is made
    sucessfully, subsequent XA_END calls for the same XID result in
    abend 5C6-00940001 in CSQMCPRH, as the logic cannot find an XTE
    associated with the connection ACE. This also results in the
    subsequent XA_END calls for the XID failing unexpectedly with
    XAER_RMERR (-3).
    

Problem conclusion

  • XA_END processing has been altered, to correctly handle the case
    where there is no associated XTE, and ensure the correct reason
    code, XAER_PROTO is returned on the subsequent XA_END call. In
    this case the QMGR should no longer abend.
    100Y
    CSQMCPRH
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI89764

  • Reported component name

    WMQ Z/OS V7

  • Reported component ID

    5655R3600

  • Reported release

    100

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-11-06

  • Closed date

    2017-11-30

  • Last modified date

    2017-12-01

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

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

    PI90533 PI90544 UI52283

Modules/Macros

  • CSQMCPRH
    

Fix information

  • Fixed component name

    WMQ Z/OS V7

  • Fixed component ID

    5655R3600

Applicable component levels

  • R100 PSY

       UP



Document information

More support for: WebSphere MQ
APAR / Maintenance

Software version: 7.1

Reference #: PI89764

Modified date: 01 December 2017


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