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PH13091: WEBSPHERE PLUG-IN HAS UNEVEN DISTRIBUTION WHEN MULTIPLE SERVERS HAVE A WEIGHT OF 0

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • WebSphere Plug-in cluster iterator does not get updated
    to the correct next member for load balancing
    

Local fix

  • N/A
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server                                      *
    ****************************************************************
    * PROBLEM DESCRIPTION: Round Robin could pick the same         *
    *                      server for a new request                *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    We found that with a large cluster of servers that has 1/2 of
    them set with a load balance weight of 0, the plugin round
    robin would pick the same server for each new request.
    

Problem conclusion

  • A bug was found within the Round Robin algorithym allowing the
    same server selection.  A fix was implemented to correctly
    track the last server picked which provides the correct
    starting point for the next new request.
    
    The fix for this APAR is currently targeted for inclusion in
    fix pack 8.5.5.17 & 9.0.5.2.  Please refer to the Recommended
    Updates page for delivery information:
    http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
    

Temporary fix

Comments

APAR Information

  • APAR number

    PH13091

  • Reported component name

    WEBS APP SERV N

  • Reported component ID

    5724H8800

  • Reported release

    850

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-06-07

  • Closed date

    2019-09-12

  • Last modified date

    2019-09-12

  • 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

    WEBS APP SERV N

  • Fixed component ID

    5724H8800

Applicable component levels

  • R850 PSY

       UP

  • R900 PSY

       UP

[{"Business Unit":{"code":"BU053","label":"Cloud \u0026 Data Platform"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"850","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
17 October 2021