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IV09149: A corrupt channel synchronization file may cause channel code to enter an infinite loop without an obvious error report

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • The channel synchronization file AMQRSYNA.DAT is located within
    the queue manager data area. This file is used as part of the
    channel synchronization mechanism. If a queue manager process
    is killed whilst this file is being updated, then as with any
    file, this action may corrupt it.
    
    A particular corruption would cause records within that file to
    be self-linked, resulting in an infinite lookup within channel
    processes.
    
    In that circumstance, it is possible that channels would fail
    to function and an FDC similar to the following could be
    written periodically (perhaps every 20 minutes). This shows an
    interminable wait for a lock within the "getkey" function.
    
    FDC file generated:
    LVLS              :- 7.0.1.2
    Probe Id          :- XC307070
    Application Name  :- MQM
    Component         :- xlsRequestMutex
    Program Name      :- amqrmppa
    Major Errorcode   :- xecL_W_LONG_LOCK_WAIT
    Probe Type        :- MSGAMQ6150
    Probe Severity    :- 3
    Probe Description :- AMQ6150: WebSphere MQ semaphore is busy.
    Comment1          :- OwningProcess(4283) Status(ACTIVE)
    Comment2          :- S (sleeping)
    MQM Function Stack
    rriCallerEntry
    rriCheckSync
    rriAccessSync
    rrxReadSync
    getkey
    xcsRequestMutexSem
    xlsRequestMutex
    xcsFFST
    

Local fix

  • If linear logging is used, the command  "rcrmqobj -m QMGRNAME -t
    syncfile" can be used to recover AMQRSYNA.DAT to a good state.
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users affected are those who have a channel synchronization
    file (AMQRSYNA.DAT) that becomes corrupted, possibly due to
    killing queue manager processes whilst it is being updated.
    
    Platforms affected:
    All Distributed (iSeries, all Unix and Windows)
    ****************************************************************
    PROBLEM SUMMARY:
    This APAR follows on from an earlier APAR IZ95863 which
    introduced a particular, specific, check to detect looping when
    processing the AMQRSYNA.DAT file. The aim with this new APAR is
    to add a check to detect any kind of corruption that could lead
    to looping.
    
    If the AMQRSYNA.DAT file is found to be corrupted then it
    should be recoverable; it may need to be manually removed first
    during a queue manager recycle. This would normally be
    undertaken through advice from IBM Service, and care should be
    taken to preserve all evidence in the event that this matter
    needs to be investigated further.
    

Problem conclusion

  • A general check for badly-linked records has been added to the
    code that manages the channel synchronization file
    AMQRSYNA.DAT. This check will report, via FDCs, that the file is
    corrupted if a badly-linked record is encountered.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
                       v6.0
    Platform           Fix Pack 6.0.2.12
    --------           --------------------
    Windows            U200331
    AIX                U842074
    HP-UX (PA-RISC)    U842208
    HP-UX (Itanium)    U842213
    Solaris (SPARC)    U842209
    Solaris (x86-64)   U842216
    iSeries            tbc_p600_0_2_12
    Linux (x86)        U842210
    Linux (x86-64)     U842215
    Linux (zSeries)    U842211
    Linux (Power)      U842212
    Linux (s390x)      U842214
    
                       v7.0
    Platform           Fix Pack 7.0.1.8
    --------           --------------------
    Windows            U200335
    AIX                U845856
    HP-UX (PA-RISC)    U847965
    HP-UX (Itanium)    U847970
    Solaris (SPARC)    U847966
    Solaris (x86-64)   U847972
    iSeries            7.0.1.8
    Linux (x86)        U847967
    Linux (x86-64)     U847971
    Linux (zSeries)    U847968
    Linux (Power)      U847969
    
                       v7.1
    Platform           Fix Pack 7.1.0.1
    --------           --------------------
    Windows            U200338
    AIX                U849732
    HP-UX (Itanium)    U850307
    Solaris (SPARC)    U850303
    Solaris (x86-64)   U850309
    iSeries            7.1.0.1
    Linux (x86)        U850304
    Linux (x86-64)     U850308
    Linux (zSeries)    U850305
    Linux (Power)      U850306
    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

    IV09149

  • 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

    2011-10-18

  • Closed date

    2012-05-24

  • Last modified date

    2012-05-24

  • 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

       UP

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Document Information

Modified date:
24 May 2012