IT10537: QUEUE MANAGER INCORRECTLY REPORTING LOG FULL WHEN THE LOG IS NOT FULL AND EXHIBITS SLOW PROCESSING

APAR status

• Closed as program error.

Error description

• Running a queue manager with long running transactions with a
  total log size of more than 4GB can lead to significant
  performance impact. MQ trace will show LOG FULL errors when the
  log is not full followed by delay in apiCheckPointPause
  function.
  
  Traces will show many entries for the following pieces of text:
  apiCheckPointPause
  hlgReserveLogSpace rc=hrcW_LOG_GETTING_VERY_FULL
  276850456  0x10806718  hrcW_LOG_GETTING_VERY_FULL
  Additional symptoms: AMQ7467 not advancing the
  linear log. Slow MQGET on cluster queue
  additional symptoms: trace Reserve Amount:
  LogBytesInUse:  also review active log space
  usage
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users using queue managers configured with recovery log size of
  more than 4 GB.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  A coding error resulted in an incorrect value comparison when
  checking recovery logs over 4 GB in size. This caused the queue
  manager to incorrectly determine that the recovery log was full,
  resulting in processing delays, and the incorrect messages being
  written to the queue manager's error log.
  

Problem conclusion

• This coding error in the MQ logger code has been addressed so
  that the value comparison is correct, and this false log full
  condition is not encountered.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.0       7.0.1.14
  v7.1       7.1.0.7
  v7.5       7.5.0.6
  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