IBM Support

IZ54623: MQ JAVA AND JMS CLIENT MESSAGE BUFFER NOT REDUCED IF MESSAGES ARE NOT RECEIVED

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • When receiving messages in either the WebSphere MQ Java or Java
    Message Service (JMS) client, the message buffer is
    automatically increased when needed to accommodate larger
    messages. If the buffer is detected to be too large for 10
    received messages, the buffer size is reduced to prevent
    excessive resource usage.
    
    If 10 messages are not received, and the requests for messages
    return 2033 (MQRC_NO_MSG_AVAILABLE), then the buffer size is not
    reduced. This can result in high Java Garbage collector
    activity.
    

Local fix

  • MQ Java client message buffer not reduced if messages are not
    received
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    This issue affects users of the WebSphere MQ classes for Java
    and classes for JMS whose applications may process large
    messages followed by small messages at a slow message rate.
    
    Platforms affected:
     All Distributed (iSeries, all Unix and Windows) +Java
    ****************************************************************
    PROBLEM SUMMARY:
    The logic to determine when to reduce the size of the message
    buffer in use did not account for the case when no message was
    received. This meant that the buffer did not reduce as quickly
    as expected.
    

Problem conclusion

  • The WebSphere MQ Java and JMS clients now reduce the incoming
    message buffer when either a series of small messages have been
    received, or after a series of 2033 (MQRC_NO_MSG_AVAILABLE)
    return codes, or a combination of both.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
                       v6.0
    Platform           Fix Pack 6.0.2.8
    --------           --------------------
    Windows            U200309
    AIX                U825517
    HP-UX (PA-RISC)    U824678
    HP-UX (Itanium)    U825875
    Solaris (SPARC)    U825511
    Solaris (x86-64)   U825872
    iSeries            tbc_p600_0_2_8
    Linux (x86)        U825181
    Linux (x86-64)     U825874
    Linux (zSeries)    U825516
    Linux (Power)      U825182
    Linux (s390x)      U825873
    
                       v7.0
    Platform           Fix Pack 7.0.1.1
    --------           --------------------
    Windows            U200310
    AIX                U827232
    iSeries            tbc_p700_0_1_1
    
    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

    IZ54623

  • Reported component name

    WMQ LIN X86 V6

  • Reported component ID

    5724H7204

  • Reported release

    601

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2009-07-06

  • Closed date

    2009-07-30

  • Last modified date

    2009-09-29

  • 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 LIN X86 V6

  • Fixed component ID

    5724H7204

Applicable component levels

  • R601 PSY

       UP

[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSCPQ5M","label":"APAR"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.0.1","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
29 September 2009