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PH27803: MQ QUEUE MANAGER DOES NOT QUIESCE AFTER STOP QMGR, THEN CANCEL, AND FORCE ARE DONE

A fix is available

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APAR status

  • Closed as program error.

Error description

  • After concurrent issues within other system applications it is
    necessary to issue a STOP against MQ. The queue manager does
    not quiesce. Subsequently, z/OS CANCEL and FORCE commands
    issued against the MQ subsystem also are unable to terminate
    it, resulting in a necessary IPL. The SRM state of MQ is left
    as "CANCEL IN PROGRESS", as MQ continues to hold an ENQueue
    against resource SYSZCSQ3 ERLYOLRH.
    .
    Additional keywords:
    ACECHNA loop
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
    *                 Release 0 Modification 0, Release 1          *
    *                 Modification 0 and Release 2 Modification 0. *
    ****************************************************************
    * PROBLEM DESCRIPTION: Various problems encountered when an    *
    *                      application connected to a queue        *
    *                      manager are terminated abnormally (for  *
    *                      example, Cancel, Force, Memterm).       *
    *                      Symptoms can include:                   *
    *                      - High CPU usage in the application,    *
    *                        queue manager, or MASTER address      *
    *                        space                                 *
    *                      - Application and/or Queue manager      *
    *                        address spaces do not end, and cannot *
    *                        be canceled or forced                 *
    *                      - Other applications hang waiting for   *
    *                        resources held by MQ                  *
    *                      In extreme cases an IPL is required to  *
    *                      resolve the problem.                    *
    ****************************************************************
    A loop was introduced into the VLCAAACE chain for an application
    address space. The cause of the loop is unknown.
    
    When the application goes through end of memory processing, or
    when the queue manager is abnormally terminated, the VLCAAACE
    chain(s) are scanned for any ACEs that require cleaning up.
    
    However due to the loop in the chain, this processing (which
    can occur in the application address space, queue manager
    address space, or MASTER (0001) address space, began looping
    indefinitely.
    

Problem conclusion

  • MQ End of Memory and Termination processing are changed to
    detect unexpected loops in the VLCAAACE chains.
    In the event of a loop being found, the queue manager is
    terminated abnormally, preventing the error impacting on other
    applications/services on the system.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PH27803

  • Reported component name

    IBM MQ Z/OS V9

  • Reported component ID

    5655MQ900

  • Reported release

    100

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-07-23

  • Closed date

    2020-12-17

  • Last modified date

    2021-03-25

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

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

    UI72157 UI72158 UI73202

Modules/Macros

  • CSQ3SSI1 CSQ3SSI2 CSQVATRM
    

Fix information

  • Fixed component name

    IBM MQ Z/OS V9

  • Fixed component ID

    5655MQ900

Applicable component levels

  • R000 PSY UI73202

       UP21/01/28 P F101

  • R100 PSY UI72157

       UP P F011

  • R200 PSY UI72158

       UP21/01/04 P F012

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.

[{"Line of Business":{"code":"LOB36","label":"IBM Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"100"}]

Document Information

Modified date:
26 March 2021