IV37600: WEBSPHERE MQ .NET CLIENT APPLICATION THAT IS BUSY DELIVERING MESSAGES, TAKES LONGER TIME TO REGISTER A MESSAGE LISTENER.

WebSphere MQ V7.0 Fix Pack 7.0.1.11

APAR status

• Closed as program error.

Error description

• WebSphere MQ 7.0.1 dot net client application is taking around
  2 minutes and sometimes even longer time to register a message
  listener. No explicit errors reported, traces shows delay in
  registering message listener.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of WebSphere MQ v7.0.1 who utilize
  asynchronous message delivery in a .Net application along with
  Read Ahead Enabled
  
  Platforms affected:
  All Distributed (iSeries, all Unix and Windows)
  ****************************************************************
  PROBLEM SUMMARY:
  When ReadAhead is enabled and DispatcherThread has a load of
  messages to be delivered, while delivering the messages,
  DispatcherThread takes DispatchLock for complete time. At the
  same time, Main thread is trying to register a message
  listener(MQCB), this requires suspending Async Service (MQCTL -
  MQOP_SUSPEND). This means MQCTL is waiting for DispatchLock to
  be released and this time difference is observed as 2 and half
  minutes. Sometimes based on number of dispatchers and messages,
  the time taken to register a message listener further increases.
  

Problem conclusion

• WebSphere MQ NMQI layer Code is modified such that MQCTL-
  MQOP_SUSPEND is issued, even before waiting for dispatchLock
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
                     v7.0
  Platform           Fix Pack 7.0.1.11
  --------           --------------------
  Windows            7.0.1.11
  AIX                7.0.1.11
  HP-UX (PA-RISC)    7.0.1.11
  HP-UX (Itanium)    7.0.1.11
  Solaris (SPARC)    7.0.1.11
  Solaris (x86-64)   7.0.1.11
  iSeries            7.0.1.11
  Linux (x86)        7.0.1.11
  Linux (x86-64)     7.0.1.11
  Linux (zSeries)    7.0.1.11
  Linux (Power)      7.0.1.11
  
  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 AIX V7

• Fixed component ID

  5724H7221

Applicable component levels

• R701 PSY

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