IT29480: High CPU observed in amqzmur0 and/or amqzmuc0 processes when using SuppressMessage tuning attribute

APAR status

• Closed as program error.

Error description

• If the queue manager is configured to suppress messages in the
  error
  log file and if the qm.ini SuppressMessage property contains a
  message ID, then the amqzmur0 and/or amqzmuc0 processes consume
  high CPU.
  
  Here is an example of setting the qm.ini file which triggers
  high CPU:
  
  QMErrorLog:
     SuppressMessage=9202
     SuppressInterval=30
  

Local fix

• To prevent high CPU usage, remove the SuppressMessage property
  from the qm.ini QMErrorLog stanza.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users of the SuppressMessage qm.ini stanza may be affected by
  this problem.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  A logic error meant that a tight loop occured when the
  SuppressInterval expires and there are outstanding messages
  matching the SuppressMessage configuration.
  

Problem conclusion

• The code was modified so that any suppressed messages are
  processed once the expiry defined by SuppressInterval is
  reached.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.1 CD    9.1.5
  v9.1 LTS   9.1.0.4
  
  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

  IBM MQ BASE MP

• Fixed component ID

  5724H7271

Applicable component levels