IT31311: MQRC_HCONN_ERROR, FDC with probe ID RM632001 generated from a call to reqGetConn

APAR status

• Closed as program error.

Error description

• <span style="background-color:rgb(255, 255, 255)">During calls
  to MQOPEN, MQCTL or MQGET a </span>
  race condition can cause MQ to generate the
  following failure data capture (FDC) record:
  
  Probe Id               :- <span style="background-color:rgb(255,
  255, 255)">RM632001</span>
  Component          :- <span style="background-color:rgb(255,
  255, 255)">reqGetConn</span>
  <span style="background-color:rgb(255, 255, 255)">Major
  Errorcode   :- MQRC_HCONN_ERROR</span>
  
  The generation of the FDC does not happen
  consistently since it is subject to the timing of two threads.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  All MQ users making calls to MQOPEN, MQCTL or MQGET.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  An error in the MQ code created a race condition where two
  threads
  attempting to access information on the same connection handle
  could interfere with
  each other and generate an FDC.
  

Problem conclusion

• The MQ code has been corrected so that the lock used to access
  connection handle
  information is now released at the correct time. This means
  multiple
  threads accessing the same connection handle information
  simultaneously will
  now wait for each other correctly, and no longer cause FDCs to
  be generated.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.1 CD    TBC.
  v9.1 LTS   9.1.0.5
  
  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 MP

• Fixed component ID

  5724H7271

Applicable component levels