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IZ44595: Exception in MQ application code leads to FDC with probe MQ000101 and the application process then exits.


You can track all active APARs for this component.


APAR status

  • Closed as program error.

Error description

  • Probe MQ000101 from MQ application process upon receipt of a
    synchronous signal.
    The MQ exception handler may fail to pass control to an
    application signal handler which was established prior to the
    first MQCONN in the process when multiple threads are
    connecting and disconnecting from the queue manager.
    After raising the FDC the application process exits with an
    exit code of the signal number. For example a SIGSEGV would
    typically lead to the process exiting with exit code 11.

Local fix

Problem summary

  • ****************************************************************
    This is a small timing window related to an synchronous signal
    (e.g SIGSEGV) being raised in the period when a new connection
    is established in a process with no other threads currently
    Note that java programs can be exposed to this error due to the
    JVM's use of synchronous signals.
    Platforms affected:
    AIX,HP-UX (Itanium),HP-UX (PA-RISC),Linux (Power),Linux (s390x),
    Linux (x86),Linux (x86-64),Linux (zSeries),Solaris (SPARC),
    Solaris (x86-64),iSeries
    The MQ exception handler receives control for an exception on a
    thread. When the signal handler gets control, it checks whether
    the exception is in MQ code, and whether the exception can be
    passed to any previously established signal handler.  A timing
    condition has been observed, that causes the MQ exception
    handler to incorrectly determine that an 'application process'
    is an MQ internal process and the signal is not passed on to any
    other signal handler, and the process is terminated. The timing
    condition relates to the state of other threads in the system.

Problem conclusion

  • The exception handler was changed to recognise this situation.
    The exception handler will now pass control to any previously
    established signal handler, or call abort() if no such signal
    handler exists. If abort() is called then a core file is
    produced where appropriate.
    The fix is targeted for delivery in the following PTFs:
    Platform           Fix Pack
    --------           --------------------
    AIX                U821719
    HP-UX (PA-RISC)    U821511
    HP-UX (Itanium)    U822328
    Solaris (SPARC)    U821514
    Solaris (x86-64)   U822359
    iSeries            tbc_p600_0_2_7
    Linux (x86)        U822325
    Linux (x86-64)     U822358
    Linux (zSeries)    U822329
    Linux (Power)      U822327
    Linux (s390x)      U822357
    Platform           Fix Pack
    --------           --------------------
    AIX                U823774
    HP-UX (PA-RISC)    U823665
    HP-UX (Itanium)    U823667
    Solaris (SPARC)    U823772
    Solaris (x86-64)   U824344
    iSeries            tbc_p700_0_1_0
    Linux (x86)        U823664
    Linux (x86-64)     U823773
    Linux (zSeries)    U823668
    Linux (Power)      U823666
    The latest available maintenance can be obtained from
    'WebSphere MQ Recommended Fixes'
    If the maintenance level is not yet available, information on
    its planned availability can be found in 'WebSphere MQ
    Planned Maintenance Release Dates'

Temporary fix


APAR Information

  • APAR number


  • Reported component name

    WMQ LIN X86 V6

  • Reported component ID


  • Reported release


  • Status


  • PE




  • Special Attention


  • Submitted date


  • Closed date


  • Last modified date


  • 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


Applicable component levels

  • R600 PSY


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Document Information

Modified date:
23 March 2009