IV52435: IF USING AIX 32 BIT APPLICATIONS DELAYS ARE SEEN IN MQCONN AND MQDISC

Fix Pack 7.1.0.5 for WebSphere MQ V7.1
WebSphere MQ V7.5 Fix Pack 7.5.0.4

APAR status

• Closed as program error.

Error description

• AIX shared-binding applications use shared memory to communicate
  with WebSphere MQ queue manager processes. Where a segment is
  being accessed by 32 bit applications, the time cost of the
  shmdt() AIX operating system call to detach shared memory is
  high. The effects of this can be seen in the MQCONN and MQDISC
  API calls, possibly taking up to 500 ms to return.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  AIX users with a high rate of MQCONN/MQDISC noticing delays
  
  
  Platforms affected:
  AIX
  
  ****************************************************************
  PROBLEM SUMMARY:
  This APAR will reduce the number of shmat/shmdt operating system
  calls being made by amqrmppa processes, which will reduce the
  cost of connect and disconnect activity across the MQ system
  as a a whole. Before this APAR, amqrmppa creates a shared memory
  attachment per thread.
  

Problem conclusion

• After the change in this APAR, a single shared memory attachment
  is created in amqrmppa that is shared by future threads. The
  number of shmat and shmdt operating system calls being made from
  the amqrmppa process is then reduced, which will reduce the
  possibility for performance bottlenecks in connect and
  disconnect activity taking place in all other WebSphere MQ
  programs.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.0       7.0.1.13
  v7.1       7.1.0.5
  v7.5       7.5.0.4
  
  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

  WMQ AIX V7

• Fixed component ID

  5724H7221

Applicable component levels

• R701 PSY

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