IT37483: High CPU usage reported for an agent process amqzlaa0 when ending the MQ queue manager

APAR status

• Closed as program error.

Error description

• MQ trace of the high CPU agent process captured while the queue
  managed ended shows one thread running repeatedly through
  following functions with no delay:
  -{  zcpReceiveOnPipe
      -}! zcpReceiveOnPipe rc=zrcC_E_SHUTDOWN FunctionTime=4
      -{  xcsCheckProcess
      -}  xcsCheckProcess rc=OK FunctionTime=7
      -{  xlsRequestMutex
      -}  xlsRequestMutex rc=OK FunctionTime=7
           ulThreadsCreated: 2085, ulThreadsCompleted: 2084,
  ulThreadsAbended: 0, ulThreadsAborted: 0, ulThreadCount: 1
      -{  xcsCheckProcess
      -}  xcsCheckProcess rc=OK FunctionTime=7
      -{  xlsReleaseMutex
      -}  xlsReleaseMutex rc=OK FunctionTime=4
      -{  zapInquireStatus
      -}  zapInquireStatus rc=OK FunctionTime=2
  
  The low FunctionTime values indicates each function took only a
  few microseconds to complete.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Any MQ administrator stopping a queue manager.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When an MQ administrator stops a queue manager, there was a
  small chance that one or more of the queue manager agent
  processes (amqzlaa0) which perform work on behalf of connected
  applications could show high CPU before terminating.  The high
  CPU does not cause any FDCs or error messages but might delay
  the completion of the endmqm command.
  

Problem conclusion

• The queue manager agent process has been corrected to ensure it
  no longer consumes high CPU cycles while the queue manager is
  ending.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.2 LTS   9.2.0.15
  v9.3 LTS   9.3.0.5
  v9.x CD    9.3.3
  
  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

  MQ BASE V9.2

• Fixed component ID

  5724H7281

Applicable component levels