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IV42468: HANG AND HIGH SHARED MEMORY USAGE WHEN QUERYING CONNECTION DATA (DIS CONN)

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • The queue manager likely to fail with one or more of the
    following FDCs.
    
    Probe Id :- XY132002
    Component :- xstCreateExtent
    Program Name :- amqzlaa0
    Probe Description :- AMQ6119: An internal WebSphere MQ error
    has occurred (Failed to get memory segment:
    shmget(0x00000000, 268435456) [rc=-1 errno=28] No space
    left on device)
    Comment2 :- No space left on device
    
    MQM Function Stack
    zlaMainThread
    zlaProcessMessage
    zlaProcessSPIRequest
    zlaSPIKernel
    zcpCreateMessage
    xcsAllocateMemBlock
    xstExtendSet
    xstCreateExtent
    xcsFFST
    
    On AIX only:
    
    Probe Id          :- XC267011
    Component         :- xehAsySignalMonitor
    Major Errorcode   :- xecE_W_UNEXPECTED_ASYNC_SIGNAL
    Probe Type        :- MSGAMQ6209
    Probe Severity    :- 3
    Probe Description :- AMQ6209: An unexpected asynchronous signal
    (33 : SIGDANGER) has been received and ignored.
    Arith1            :- 33 (0x21)
    Arith2            :- 10354928 (0x9e00f0)
    Comment1          :- SIGDANGER
    
    All platforms:
    
    "ipcs -a" output likely to show lot of shared memory segments
    allocated from mqm user
    
    This problem might also occur when querying non connection data
    (e.g. queue or channel data) that results in request for a
    bigger shared memory segment.
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users using queue managers with lot of connections in a system
    running with 8 or more CPUs will be more affected by this
    problem when comparing with a system running with 4 CPUs and
    same number of connections.
    
    Platforms affected:
    All Distributed (iSeries, all Unix and Windows)
    ****************************************************************
    PROBLEM SUMMARY:
    When allocating shared memory WebSphere MQ 7.1 and 7.5 use a
    resource locking optimization based on the number of
    processors. This optimization caused requests for large amounts
    of memory to fail and then retry until all of system shared
    memory was consumed.
    

Problem conclusion

  • The optimization has been modified to ensure that any
    allocation request considers the size of the request before
    using the calculation with the number of processors to ensure
    the allocation request is successful.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v7.1       7.1.0.4
    v7.5       7.5.0.3
    
    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

    IV42468

  • Reported component name

    WMQ LIN X86 V7

  • Reported component ID

    5724H7224

  • Reported release

    710

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2013-05-13

  • Closed date

    2013-05-31

  • Last modified date

    2014-06-23

  • 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 V7

  • Fixed component ID

    5724H7224

Applicable component levels

[{"Line of Business":{"code":"LOB36","label":"IBM Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSFKSJ","label":"WebSphere MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.1"}]

Document Information

Modified date:
25 March 2021