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IT15770: MQV8 MEMORY LEAK IN PUBSUB TOPIC SCAVENGER ROUTINE

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APAR status

  • Closed as program error.

Error description

  • Available memory on the system may either become exhausted or
    may be seen to be increasing in an unbounded manner.
    
    Further investigation may show that the Java JVM process and the
    MQ amqzmuc0 process are using a large amount of memory.
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users with large number of topic nodes in their topic tree may
    encounter this issue.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    The topic scavenger routine which checks and reclaims the space
    used
    by dynamic topic nodes did not correctly free all allocated
    memory for nodes
    in the topic tree, once the memory was no longer required,
    resulting in a rise in reported memory usage.
    

Problem conclusion

  • The code has been modified to free memory associated with a
    topic node once it is removed from the tree.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v8.0       8.0.0.7
    v9.0 CD    9.0.2
    v9.0 LTS   9.0.0.2
    
    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

    IT15770

  • 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

    2016-06-17

  • Closed date

    2017-02-20

  • Last modified date

    2020-07-27

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

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

    PH27898

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"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"8.0.0.0","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
28 July 2020