IT31820: PipeLineLength=2 channel ends and writes FDC with probe XC006001including error code xecS_I_PRIVATE_MEMORY_ERROR

APAR status

• Closed as program error.

Error description

• When a PipeLineLength=2 ("Dual Unit of Work") channel thread
  terminates it fails to free a block of memory and generates the
  following FDC:
  
      Probe Id          :- XC006001
      Component         :- xcsFreeMemFn
      Program Name      :- amqrmppa
      Major Errorcode   :- xecS_I_PRIVATE_MEMORY_ERROR
      Probe Description :- AMQ6091: An internal IBM MQ error has
  occurred
      Comment1          :- invalid head tag
  
  MQM Function Stack
  rriRecvThread2
  xcsFreeMemFn
  xcsFFST
  

Local fix

• Set PipeLineLength=1 in qm.ini so Dual-Unit of Work threads are
  not used.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  MQ users who make use of the Dual-Unit of Work feature, by
  setting PipeLineLength=2 in qm.ini.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  The pointer to a memory area used by MQ to receive incoming
  messages was incorrect at the point a terminating Dual-Unit of
  Work thread was trying to free the memory to the system. This
  caused a Private Memory FDC to be generated which reported an
  "invalid head tag".
  

Problem conclusion

• The MQ code has been corrected so that the memory block for the
  stage area is correctly freed, preventing the FDC.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.0 LTS   9.0.0.10
  v9.1 LTS   9.1.0.6
  v9.x CD    9.2.0
  
  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 M/P

• Fixed component ID

  5724H7261

Applicable component levels