IT34273: Performance overheads due to frequent loading and unloading of deep queues.

APAR status

• Closed as program error.

Error description

• When accessing deep queues, the users might observe delays in
  MQAPIs
  (MQGET, MQPUT, MQOPEN etc). FDCs with LONG_LOCK_WAIT errors
  might
  also be generated.
  

Local fix

• Ensure deep queues are not loaded/unloaded often by maintaining
  an open handle on the queues.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users using MQ with deep queues
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When a queue is infrequently referenced it is unloaded and
  reloaded at each reference.
  If the queue is deep and if it is loaded/unloaded often then it
  affects MQ performance.
  
  This unloading is only performed for queues which have no open
  application handles (input or output) against them at the point
  at which the cleanup is performed.
  

Problem conclusion

• The queue manager logic has been modified to consider the queue
  depth when unloading infrequently referenced queues.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.0 LTS   9.0.0.11
  v9.x CD    9.2.2
  
  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 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 M/P

• Fixed component ID

  5724H7261

Applicable component levels