IBM Support

IT35074: Potential memory leak during of cached resources in multi threaded asynchronous consume client application

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APAR status

  • Closed as program error.

Error description

  • When a thread releases shared memory pipe resources, they are
    placed in a cache for reuse.  A race condition exists whereby a
    shared memory block may be leaked if two threads compete to
    free up the resources at the same time.
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Multi-threaded asynchronous consume client applications
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    When a client thread ends or calls MQDISC, the associated
    resources for the connection are cleaned up and cached for reuse
    by another thread. When there were multiple threads ending their
    connections concurrently, a race condition existed that could
    allow a memory leak of the resource.
    

Problem conclusion

  • The MQ client application logic has been corrected to avoid this
    timing window, so that the cached resources are freed correctly.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v9.0 LTS   9.0.0.12
    v9.1 LTS   9.1.0.8
    v9.2 LTS   9.2.0.2
    v9.x CD    9.2.2
    
    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

    IT35074

  • Reported component name

    MQ BASE V9.2

  • Reported component ID

    5724H7281

  • Reported release

    920

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-11-26

  • Closed date

    2021-01-22

  • Last modified date

    2021-01-22

  • 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

    MQ BASE V9.2

  • Fixed component ID

    5724H7281

Applicable component levels

[{"Line of Business":{"code":"LOB36","label":"IBM Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"920"}]

Document Information

Modified date:
25 March 2021