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IT15281: IBM MQ CLUSTERING WORKLOAD IS NOT BALANCING

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APAR status

  • Closed as program error.

Error description

  • When messages are put to a queue where many instances exist in a
    cluster, not all available destinations receive those messages
    as might be expected.
    
    The cluster cache information for those destinations not
    receiving those messages,
    indicates that the corresponding channels (either CLUSSDR or
    CLUSRCVR for the local queue manager) are not in RUNNING state.
    This is inconsistent with the actual channel state as indicated
    by MQSC (dis chs) and causes the destination not to be selected
    by the workload management algorithm.
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users using queue manager clusters.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    Workload balancing did not function correctly due to stale
    channel status being stored in the cluster cache.
    
    For example,  if the channel status stored in the cluster
    repository cache was STARTING while the channel was actually
    RUNNING (and there are other available destinations with RUNNING
    channels) this channel was considered to be less significant to
    the workload management algorithm and therefore not chosen for
    load balancing.
    

Problem conclusion

  • The code has been modified to pick the current status of the
    channel from the channel status table and also update the
    cluster cache with the current information obtained.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v7.5       7.5.0.8
    v8.0       8.0.0.2
    
    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

    IT15281

  • Reported component name

    WEBSPHERE MQ 7.

  • Reported component ID

    5724H7240

  • Reported release

    750

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-05-23

  • Closed date

    2016-10-25

  • Last modified date

    2017-11-24

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

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

    PI71165

Fix information

  • Fixed component name

    WEBSPHERE MQ 7.

  • Fixed component ID

    5724H7240

Applicable component levels

[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSCPQ63","label":"APAR \/ Maintenance"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.5","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
24 November 2017