IBM Support

PM99286: WMQ Z/OS: QUEUE MANAGER HANGS DURING SHUTDOWN IF STRUCTURE FAILURE OCCURS

A fix is available

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • If a structure failure occurs during normal QMGR shut-down, it
    is possible that structure failure processing gets into a
    deadlock with the shutdown checkpoint, causing both to hang.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
    *                 Release 1 Modification 0.                    *
    ****************************************************************
    * PROBLEM DESCRIPTION: The queue manager hangs during the      *
    *                      shutdown process if a structure failure *
    *                      occurred.                               *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    During checkpoint processing, the queue manager goes through
    shared queues that are open in the CF manager. If the queue
    manager is processing the termination checkpoint, all queues are
    closed.
    To do so, the TCB on which checkpoint processing runs obtains
    the IVSA latch, and schedules a synchronous close request to the
    CF manager.
    At the same time the CF manager receives a structure failure
    event for the CF structure and starts processing to handle it.
    This includes scanning through the chain of open queues and
    closing them, which also requires the IVSA latch.
    As the close request is scheduled on the same task where
    structure failure processing is running in an SRB, a dead-lock
    occurs and both checkpoint processing and structure failure
    processing are hanging, rendering the structure unusable and
    preventing the checkpoint from completing, causing the queue
    manager to hang.
    

Problem conclusion

  • The code was changed to stop structure failure processing for a
    tolerated failure if the queue manager is shutting down,
    allowing the termination checkpoint to complete and the queue
    manager to end.
    100Y
    CSQEESTP
    CSQESTFA
    

Temporary fix

Comments

APAR Information

  • APAR number

    PM99286

  • 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

    2013-10-16

  • Closed date

    2014-01-13

  • Last modified date

    2014-03-03

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

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

    UI14174

Modules/Macros

  • CSQEESTP CSQESTFA
    

Fix information

  • Fixed component name

    WMQ Z/OS V7

  • Fixed component ID

    5655R3600

Applicable component levels

  • R100 PSY UI14174

       UP14/02/05 P F402

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.

[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG19M","label":"APARs - z\/OS environment"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.1","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
03 March 2014