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IV52435: IF USING AIX 32 BIT APPLICATIONS DELAYS ARE SEEN IN MQCONN AND MQDISC

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APAR status

  • Closed as program error.

Error description

  • AIX shared-binding applications use shared memory to communicate
    with WebSphere MQ queue manager processes. Where a segment is
    being accessed by 32 bit applications, the time cost of the
    shmdt() AIX operating system call to detach shared memory is
    high. The effects of this can be seen in the MQCONN and MQDISC
    API calls, possibly taking up to 500 ms to return.
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    AIX users with a high rate of MQCONN/MQDISC noticing delays
    
    
    Platforms affected:
    AIX
    
    ****************************************************************
    PROBLEM SUMMARY:
    This APAR will reduce the number of shmat/shmdt operating system
    calls being made by amqrmppa processes, which will reduce the
    cost of connect and disconnect activity across the MQ system
    as a a whole. Before this APAR, amqrmppa creates a shared memory
    attachment per thread.
    

Problem conclusion

  • After the change in this APAR, a single shared memory attachment
    is created in amqrmppa that is shared by future threads. The
    number of shmat and shmdt operating system calls being made from
    the amqrmppa process is then reduced, which will reduce the
    possibility for performance bottlenecks in connect and
    disconnect activity taking place in all other WebSphere MQ
    programs.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v7.0       7.0.1.13
    v7.1       7.1.0.5
    v7.5       7.5.0.4
    
    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

    IV52435

  • Reported component name

    WMQ AIX V7

  • Reported component ID

    5724H7221

  • Reported release

    701

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-11-22

  • Closed date

    2014-01-20

  • Last modified date

    2014-01-20

  • 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 AIX V7

  • Fixed component ID

    5724H7221

Applicable component levels

  • R701 PSY

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Document Information

Modified date:
20 January 2014