IBM Support

IT09502: WMQ V8 QUEUE MANAGER EXHIBITS SLOW PROCESSING WHEN FORMATTING SECONDARY LOG EXTENTS DUE TO LONG RUNNING TRANSACTIONS

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Running WMQ v8 and processing long running transactions with a
    small number of primary log extents can lead to significant
    performance impacts while the queue manager formats its
    secondary log extents.
    

Local fix

  • Extending the number of primary logfiles can help to workaround
    the performance impact.
    

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    This issue affects users of MQ version 8 who are using
    transactions, and have configured a small number of primary log
    extents. This issue is more likely to be prevalent if the system
    also maintains long-running transactions.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    When the queue manager detects that primary log extents are
    approaching capacity, it is expected that the queue manager will
    delay lower priority log writes until more space is available. A
    logic error meant that the queue manager incorrectly detected
    the log full condition and applied this throttling to log
    updates, even though sufficient space was available. This lead
    to delays in processing.
    

Problem conclusion

  • The queue manager logic has been updated to prevent this
    erroneous detection of a log full condition.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v8.0       8.0.0.4
    
    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

    IT09502

  • Reported component name

    WMQ BASE MULTIP

  • Reported component ID

    5724H7251

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2015-06-18

  • Closed date

    2015-08-20

  • Last modified date

    2015-08-20

  • 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

    WMQ BASE MULTIP

  • Fixed component ID

    5724H7251

Applicable component levels

  • R800 PSY

       UP



Document information

More support for: IBM MQ

Software version: 8.0.0.0

Reference #: IT09502

Modified date: 20 August 2015