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

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 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