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IT10537: QUEUE MANAGER INCORRECTLY REPORTING LOG FULL WHEN THE LOG IS NOT FULL AND EXHIBITS SLOW PROCESSING

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Running a queue manager with long running transactions with a
    total log size of more than 4GB can lead to significant
    performance impact. MQ trace will show LOG FULL errors when the
    log is not full followed by delay in apiCheckPointPause
    function.
    
    Traces will show many entries for the following pieces of text:
    apiCheckPointPause
    hlgReserveLogSpace rc=hrcW_LOG_GETTING_VERY_FULL
    276850456  0x10806718  hrcW_LOG_GETTING_VERY_FULL
    Additional symptoms: AMQ7467 not advancing the
    linear log. Slow MQGET on cluster queue
    additional symptoms: trace Reserve Amount:
    LogBytesInUse:  also review active log space
    usage
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users using queue managers configured with recovery log size of
    more than 4 GB.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    A coding error resulted in an incorrect value comparison when
    checking recovery logs over 4 GB in size. This caused the queue
    manager to incorrectly determine that the recovery log was full,
    resulting in processing delays, and the incorrect messages being
    written to the queue manager's error log.
    

Problem conclusion

  • This coding error in the MQ logger code has been addressed so
    that the value comparison is correct, and this false log full
    condition is not encountered.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v7.0       7.0.1.14
    v7.1       7.1.0.7
    v7.5       7.5.0.6
    v8.0       8.0.0.4
    
    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

    IT10537

  • Reported component name

    WMQ BASE MULTIP

  • Reported component ID

    5724H7251

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2015-08-06

  • Closed date

    2015-10-06

  • Last modified date

    2017-01-31

  • 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

    WMQ BASE MULTIP

  • Fixed component ID

    5724H7251

Applicable component levels

  • R800 PSY

       UP



Document information

More support for: IBM MQ

Software version: 8.0.0.0

Reference #: IT10537

Modified date: 31 January 2017