IBM Support

PH08454: MQ Z/OS V9:ABN=5C6-00E50001,LOC=CSQELPLM.CSQEWCMQ+00000712

A fix is available

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Customer complained that one queue manager in queue sharing
    group took following abend:
    CSQA,ABN=5C6-00E50001,U=SYSOPR  ,
    -CSQEWCMQ,M=CSQGFRCV,LOC=CSQELPLM.CSQEWCMQ
    
    The abend occurred while resolving an indoubt QSG disposition
    unit of work, where the unit of work contained puts to a shared
    queue that were performed on a qmgr other than the one
    performing the resolve, and which is no longer running.
    CSQERRIN obtained a latch to serialise remote resolve
    processing, and called CSQERIND, which rebuilt the control
    blocks representing the uow operations. It then called CSQESYNC
    to commit the UOW. As part of this CSQEKATM was called to
    determine if the committed puts required any  other qmgrs to be
    notified (for example, due to triggering).
    However the IVSA pointer for the queue was not set, leading to
    these  checks being done using the contents of low core.
    Normally this results in it determining that no broadcast is
    required,  however in this instance, the values in low core
    caused CSQEWCMQ to be called to perform the notification - this
    requested the PCT latch, but as this has the same class as the
    remote resolve latch, a hierarchy violation was detected and
    the abend occurred.
    
    Additional Symptom(s) Search Keyword(s):
    

Local fix

  • n/a
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
    *                 Release 0 Modification 0 and Release 1       *
    *                 Modification 0.                              *
    ****************************************************************
    * PROBLEM DESCRIPTION: Abend 5C6-00E50001 occurs in CSQEWCMQ   *
    *                      when an indoubt group unit of recovery  *
    *                      is resolved by committing the UR.       *
    ****************************************************************
    While committing an indoubt group unit of recovery for an
    inactive peer, CSQERIND calls CSQESYNC to commit any shared
    queue operations in the UR, while holding the remote resolve
    latch.
    CSQESYNC then calls CSQEKATM to check if any K&T notifications
    should be broadcast to other queue managers.
    However, the ivsa address is not available, leading to the
    notifications being generated based on values in low core.
    
    If any notifications are generated, CSQEWCMQ is called and
    attempts to get the PCT latch. However this latch conflicts
    with the remote resolve latch already held, leading to the
    reported latch hierarchy violation abend.
    

Problem conclusion

  • CSQEKATM is changed to check if the IVSA address is set before
    using it to check if any notifications are required.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PH08454

  • Reported component name

    IBM MQ Z/OS V9

  • Reported component ID

    5655MQ900

  • Reported release

    000

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-02-12

  • Closed date

    2019-02-27

  • Last modified date

    2019-05-02

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

    PI91842

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

    UI61532 UI61533

Modules/Macros

  • CSQEKATM
    

Fix information

  • Fixed component name

    IBM MQ Z/OS V9

  • Fixed component ID

    5655MQ900

Applicable component levels

  • R000 PSY UI61532

       UP19/04/11 P F904

  • R100 PSY UI61533

       UP19/04/11 P F904

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.



Document information

More support for: IBM MQ

Software version: 9.0

Reference #: PH08454

Modified date: 02 May 2019