IBM Support

IT29528: Deadlock in publish/subscribe followed by queue manager hang with LONG_LOCK_WAIT FDCs

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • The queue manager hung when creating subscription or publishing
    message and FDCs XC514090 from component xlsRWMutexReques,
    error code xecL_W_LONG_LOCK_WAIT and the
    following function stacks.
    
    MQM Function Stack
    zlaMainThread
    zlaProcessMessage
    zlaProcessMQIRequest
    zlaMQPUT
    zsqMQPUT
    kpiMQPUT
    kqiPutTopic
    kqiTopicGetNextSubscriber
    xlsRWMutexRequest
    xcsFFST
    
    kpiMQSUB
    kqiSubscribeTopic
    kqiCreateSubscription
    kqiHandleRetainedPubs
    kqiDeliverRetainedPublication
    kqiTopicCalculateRetained
    kqiProcessRetainedIdCB
    kqiResolveTopic
    kqiTopicLocateParent
    xlsRWMutexRequest
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users using MQ Publish/Subscribe with retained publication.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    A defect in the MQ pub/sub code meant that the queue manager did
    not follow the appropriate pub/sub locking hierarchy when create
    a subscription with a retained publication. This introduced a
    timing window which could cause a deadlock between MQ threads
    and hang in the queue manager.
    

Problem conclusion

  • MQ pub/sub code has been modified to resolve the MQ pub/sub
    locking problem.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v8.0       8.0.0.14
    v9.0 LTS   9.0.0.9
    v9.1 CD    9.1.5
    v9.1 LTS   9.1.0.4
    
    The latest available maintenance can be obtained from
    'WebSphere MQ Recommended Fixes'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
    
    If the maintenance level is not yet available information on
    its planned availability can be found in 'WebSphere MQ
    Planned Maintenance Release Dates'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
    ---------------------------------------------------------------
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT29528

  • Reported component name

    IBM MQ BASE MP

  • Reported component ID

    5724H7271

  • Reported release

    910

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-06-24

  • Closed date

    2019-10-25

  • Last modified date

    2019-10-25

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

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

Fix information

  • Fixed component name

    IBM MQ BASE MP

  • Fixed component ID

    5724H7271

Applicable component levels

  • R910 PSY

       UP

[{"Line of Business":{"code":"LOB36","label":"IBM Automation"},"Business Unit":{"code":"BU053","label":"Cloud \u0026 Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"910"}]

Document Information

Modified date:
26 August 2021