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IV25859: Probe ZC045010 and XC332063 FDCs for application using Shared HCONNs with Linux Threads at MQ 6.0.2.11 or later.

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APAR status

  • Closed as program error.

Error description

  • Probe ZC045010 FDCs from function zcpError and probe XC332063
    FDCs from xlsWaitEvent, together with those FDCs identifying
    that the ThreadingModel is LinuxThreads, is a good indicator of
    encountering this issue.
    
    The issue also requires that the application reporting the probe
    XC332063 FDCs is using shared HCONNs. This is indicated if the
    FDC Trace History shows references to zutAquireSharedPCD and
    zutReleaseSharedPCD functions.
    

Local fix

  • If there is no specific need, avoid the use of the Linux
    threading model by removing the LD_ASSUME_KERNEL=2.4.19
    environment variable setting for the queue manager and
    applications.
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    You may be exposed to this issue if you have ALL of the
    following: using MQ V6.0.2.11 or later MQ V6 fixpacks; using
    the Linux thread model (because you have set environment
    variable LD_ASSUME_KERNEL=2.4.19); and you have applications
    using shared HCONNs.
    
    Platforms affected:
    Linux (Power),Linux (s390x),Linux (x86),Linux (x86-64),
    Linux (zSeries)
    
    ****************************************************************
    PROBLEM SUMMARY:
    Use of Linux threads causes particular difficulties for the
    queue manager checking the liveness of processes. The queue
    manager must be particularly careful to ensure the check is made
    against the process id, not against the Linux thread-process.
    
    Unfortunately, some cleanup checking introduced at MQ 6.0.2.11
    mistakenly did use the thread-process, causing an issue in the
    circumstance where the connecting application used a shared
    HCONN.
    

Problem conclusion

  • The cleanup checking was corrected to avoid making a liveness
    check against a Linux thread-process.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
                       v6.0
    Platform           Fix Pack 6.0.2.12
    --------           --------------------
    Linux (x86)        U842210
    Linux (x86-64)     U842215
    Linux (zSeries)    U842211
    Linux (Power)      U842212
    Linux (s390x)      U842214
    
    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

    IV25859

  • Reported component name

    WMQ LIN X86 V6

  • Reported component ID

    5724H7204

  • Reported release

    602

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-08-07

  • Closed date

    2012-08-21

  • Last modified date

    2012-08-21

  • 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

  • R602 PSY

       UP

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Document Information

Modified date:
21 August 2012