IC97468: 32-BIT APPLICATIONS RESERVING LARGE AMOUNT OF HEAP MEMORY AND/OR SHARED MEMORY SEGMENTS FAIL TO CONNECT TO WMQ V7.X QMGR

WebSphere MQ V7.0 Fix Pack 7.0.1.12
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

• A 32-bit application which is memory intensive, such as
  WebSphere Application Server or WebSphere Message Broker, may
  fail to connect to a V7.x queue manager, as it may run short of
  process address space and consequently fail to attach to queue
  manager related shared memory resources.
  The error will accompany FDCs with probe ID XY129037 reporting
  errno=24 (EMFILE - The process file table is full) from shmat()
  function. Major Errorcode reported in the FDC will be:
  xecX_E_SEGMENT_TABLE_FULL
  The error logs under /var/mqm/errors directory will record
  "AMQ6207: Failed to attach shared memory segment as Segment
  table is Full." - error message.
  

Local fix

• See technote 1298595 for available options.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users using 32 bit applications which connect to queue manager
  in shared binding mode in AIX
  
  
  Platforms affected:
  AIX
  
  ****************************************************************
  PROBLEM SUMMARY:
  In order to connect to a local queue manager, MQ needs to attach
  to a trace shared memory segment and an IPCC shared memory
  segment. The IPCC shared memory segment used to be exactly
  256MB, but that meant that MQ needed at least two free
  segments to connect successfully. The APAR IY99425 introduced
  a change in MQ v6 to accommodate trace and ipcc segments in a
  single 256 MB shared memory segment by reducing the size of IPCC
  segment by the size of the trace segment. However in MQ V7 and
  higher versions, due to miscalculation in the trace segment
  size, MQ was not able to accommodate the trace and ipcc segments
  in a single 256 MB shared memory segment.
  

Problem conclusion

• MQ has been modified to correct the miscalculation in the
  trace segment size so that trace and shared memory segments
  can be accommodated in a single 256 MB shared memory segment.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.0       7.0.1.12
  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 BASE MULTIP

• Fixed component ID

  5724H7241

Applicable component levels

• R750 PSY

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