IBM Support

IT23815: The IBM MQ amqfcxba process consumes large amounts of memory.

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APAR status

  • Closed as program error.

Error description

  • Operating system commands to measure memory use show that the
    amqfcxba process
    consumes large amounts of memory.  This memory use increases
    over a period of
    time.
    

Local fix

  • The leak should in most cases occur relatively slowly and so it
    may be possible to schedule suitably regular queue manager
    restarts to work around the problem.
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    The problem may affect users of IBM MQ 7.5 who are using
    distributed publish/subscribe.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    When using distributed publish/subscribe to publish messages
    across multiple queue managers then a routing fingerprint is
    added to each published message by the queue manager:
    
    https://www.ibm.com/support/knowledgecenter/en/SSFKSJ_8.0.0/com.
    ibm.mq.tro.doc/q005490_.htm
    
    When adding this routing fingerprint, around 250 bytes of memory
    was potentially leaked from the amqfcxba process.  A system with
    a very high volume of published messages may have been at risk
    of eventually running out of memory.
    

Problem conclusion

  • The code was corrected so that allocated memory is correctly
    freed.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v7.5       7.5.0.9
    v8.0       8.0.0.5
    
    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

    IT23815

  • Reported component name

    WEBSPHERE MQ 7.

  • Reported component ID

    5724H7240

  • Reported release

    750

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2018-01-23

  • Closed date

    2018-02-23

  • Last modified date

    2018-02-23

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

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

    PI94207

Fix information

  • Fixed component name

    WEBSPHERE MQ 7.

  • Fixed component ID

    5724H7240

Applicable component levels



Document information

More support for: WebSphere MQ
APAR / Maintenance

Software version: 7.5

Reference #: IT23815

Modified date: 23 February 2018


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