IT23220: Once per hour MQPUT or MQOPEN for cluster queues can be slower than usual

APAR status

• Closed as program error.

Error description

• The MQ cluster cache is maintained approximately once per hour
  on each queue manager that participates in a cluster or
  clusters.
  
  During this time the local queue manager's cache cannot be
  queried by
  - MQOPEN calls that specify MQOO_BIND_ON_OPEN, or
  - MQPUT calls where the object handle was opened earlier by
  MQOPEN specifying MQOO_BIND_NOT_FIXED.
  
  In large scale environments (thousands of local or remote
  clustered queues known to the local queue manager, thousands of
  connected applications performing lookups) the hourly task was
  taking a few seconds, causing the above calls to wait, up to a
  few seconds.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users with thousands of cluster queues (locally or remotely
  defined) and thousands of connected applications on the local
  queue manager.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  There was an inefficiency in the algorithm that was checking
  whether memory areas could be freed.
  

Problem conclusion

• The inefficiency has been removed. In testing, a maintenance
  cycle that previously took ten seconds now completes in less
  than one second after the application of this change.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.5       7.5.0.9
  v8.0       8.0.0.10
  v9.0 LTS   9.0.0.5
  
  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:

  PI96655

Fix information

• Fixed component name

  IBM MQ BASE MP

• Fixed component ID

  5724H7251

Applicable component levels