IBM Support

IT37576: MQ runmqlsr process might enter an infinite loop and consume a high amount of CPU

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APAR status

  • Closed as program error.

Error description

  • The runmqlsr process is consuming a high amount of CPU.
    
    The trace associated with the runmqlsr process is filled with:
    
        ----{  xcsConnectSharedMemSet
        ----}! xcsConnectSharedMemSet rc=xecL_E_INVALID_PARAM
    

Local fix

  • Restart of the listener.
    
    or
    
    If a restart of the listener alone does not help, restart both
    the listener and the queue manager.
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    All users of MQ.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    runmqlsr was attempting to start up a channel, and in the course
    of that activity, it encountered an internal error when trying
    to attach to a shared memory segment.  The handling of this
    internal error was incorrect, leading to a never-ending loop
    trying the same thing, which was always failing.
    

Problem conclusion

  • The MQ code has been corrected so that, in this error branch, an
    FDC record will be written, and the operation will correctly
    fail.  There will be no similar high-CPU condition.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v9.0 LTS   9.0.0.12
    v9.1 LTS   9.1.0.10
    v9.2 LTS   9.2.0.4
    v9.x CD    9.2.4
    
    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

    IT37576

  • Reported component name

    IBM MQ BASE M/P

  • Reported component ID

    5724H7261

  • Reported release

    900

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2021-07-12

  • Closed date

    2021-08-26

  • Last modified date

    2021-08-26

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    PH40143

Fix information

  • Fixed component name

    IBM MQ BASE M/P

  • Fixed component ID

    5724H7261

Applicable component levels

[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.0"}]

Document Information

Modified date:
27 August 2021