IBM Support

IT31820: PipeLineLength=2 channel ends and writes FDC with probe XC006001including error code xecS_I_PRIVATE_MEMORY_ERROR

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APAR status

  • Closed as program error.

Error description

  • When a PipeLineLength=2 ("Dual Unit of Work") channel thread
    terminates it fails to free a block of memory and generates the
    following FDC:
    
        Probe Id          :- XC006001
        Component         :- xcsFreeMemFn
        Program Name      :- amqrmppa
        Major Errorcode   :- xecS_I_PRIVATE_MEMORY_ERROR
        Probe Description :- AMQ6091: An internal IBM MQ error has
    occurred
        Comment1          :- invalid head tag
    
    MQM Function Stack
    rriRecvThread2
    xcsFreeMemFn
    xcsFFST
    

Local fix

  • Set PipeLineLength=1 in qm.ini so Dual-Unit of Work threads are
    not used.
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    MQ users who make use of the Dual-Unit of Work feature, by
    setting PipeLineLength=2 in qm.ini.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    The pointer to a memory area used by MQ to receive incoming
    messages was incorrect at the point a terminating Dual-Unit of
    Work thread was trying to free the memory to the system. This
    caused a Private Memory FDC to be generated which reported an
    "invalid head tag".
    

Problem conclusion

  • The MQ code has been corrected so that the memory block for the
    stage area is correctly freed, preventing the FDC.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v9.0 LTS   9.0.0.10
    v9.1 LTS   9.1.0.6
    v9.x CD    9.2.0
    
    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

    IT31820

  • 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

    2020-02-11

  • Closed date

    2020-04-28

  • Last modified date

    2021-09-01

  • 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

    IBM MQ BASE M/P

  • Fixed component ID

    5724H7261

Applicable component levels

[{"Line of Business":{"code":"LOB36","label":"IBM Automation"},"Business Unit":{"code":"BU053","label":"Cloud \u0026 Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.0"}]

Document Information

Modified date:
02 September 2021