IBM Support

IT23218: Delay observed during strmqm when starting queue manager with many message on the SYSTEM.DURABLE.SUBSCRIBER.QUEUE

Subscribe to this APAR

By subscribing, you receive periodic emails alerting you to the status of the APAR, along with a link to the fix after it becomes available. You can track this item individually or track all items by product.

Notify me when this APAR changes.

Notify me when an APAR for this component changes.

 

APAR status

  • Closed as program error.

Error description

  • strmqm takes a long time to complete if there are thousands of
    messages on the SYSTEM.DURABLE.SUBSCRIBER.QUEUE.
    
    From AMQERR01.LOG the delay is observed between the following
    two messages:
    
    AMQ5051: The queue manager task 'DUR-SUBS-MGR' has started.
    AMQ5037: The queue manager task 'MARKINTSCAN' has started.
    

Local fix

  • na
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users with queue managers that serve many applications that
    create durable subscriptions.  These queue managers can validly
    have thousands of messages on their
    SYSTEM.DURABLE.SUBSCRIBER.QUEUE.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    A long delay (several minutes) during execution of the strmqm
    command, due to the large amount of processing required for the
    SYSTEM.DURABLE.SUBSCRIBER.QUEUE.
    
    The activity taking place on this queue during strmqm was
    "reconciling durable subscribers". This task involved reading
    back state information for each subscriber, and reconciling
    these into an active status record for each subscriber. To do
    this MQ has to access the queue many times, which may cause a
    delay if the number of messages on the queue is large.
    Efficiencies were identified which could reduce the overhead of
    this necessary processing.
    

Problem conclusion

  • A more efficient hashing mechanism has been implemented in order
    to reduce the amount of work required at this stage in queue
    manager startup.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v8.0       8.0.0.9
    v9.0 CD    9.0.5
    v9.0 LTS   9.0.0.3
    
    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

    IT23218

  • Reported component name

    IBM MQ BASE MP

  • Reported component ID

    5724H7251

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-11-23

  • Closed date

    2017-12-07

  • Last modified date

    2017-12-07

  • 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

    IBM MQ BASE MP

  • Fixed component ID

    5724H7251

Applicable component levels

  • R800 PSY

       UP

[{"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:
07 December 2017