IBM Support

IT14042: IBM MQ C client application fails to reconnect reporting memory access violation while the queue manager is ending

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APAR status

  • Closed as program error.

Error description

  • The application is running with WebSphere MQ 8.0 client. When
    the queue manager is ending, the application fails to reconnect
    and reports access violation. The error is reported in a Failure
    Data Capture (FDC) file as below:
    
    +++Begin+++
    | Probe Id          :- XC130031
    | Component         :- xehExceptionHandler
    | Major Errorcode   :- xecF_E_UNEXPECTED_SYSTEM_RC
    | Comment1          :- Access Violation at address 00000034
    when writing
    ....
    MQM Function Stack
    MQCONNX
    trmzstMQCONNX
    reqDoConnect
    reqConnectChl
    ccxCloneConv
    xcsFFST
    +++End+++
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users of IBM MQ client applications which attempt to reconnect
    and reuse a broken connection handle mutliple times.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    When a reconnectable IBM MQ client experiences a
    MQRC_CONNECTION_BROKEN error, it then issues a new MQCONNX call
    on the same thread with the HCONN that exists from the previous
    connection.
    
    During this process an error in the MQ client code caused it to
    invalidate some internal information in the client's internal
    channel status table. On subsequent reconnection attempts, this
    status information caused an invalid memory access, which
    generated the FDC file and caused the connection attempt to
    fail.
    

Problem conclusion

  • The MQ client code has been corrected to prevent invalidating
    the information in the internal channel status table.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v8.0       8.0.0.6
    v9.0 LTS   9.0.0.5
    
    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

    IT14042

  • Reported component name

    WMQ BASE MULTIP

  • Reported component ID

    5724H7251

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-02-29

  • Closed date

    2018-04-23

  • Last modified date

    2018-04-23

  • 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 BASE MULTIP

  • Fixed component ID

    5724H7251

Applicable component levels

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"8.0.0.0","Edition":"","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
23 April 2018