IT14042: IBM MQ C client application fails to reconnect reporting memory access violation while the queue manager is ending

APAR status

• Closed as program error.

Error description

• The application is running with WebSphere MQ 8.0 client. When
  the queue manager is ending, the application fails to reconnect
  and reports access violation. The error is reported in a Failure
  Data Capture (FDC) file as below:
  
  +++Begin+++
  | Probe Id          :- XC130031
  | Component         :- xehExceptionHandler
  | Major Errorcode   :- xecF_E_UNEXPECTED_SYSTEM_RC
  | Comment1          :- Access Violation at address 00000034
  when writing
  ....
  MQM Function Stack
  MQCONNX
  trmzstMQCONNX
  reqDoConnect
  reqConnectChl
  ccxCloneConv
  xcsFFST
  +++End+++
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users of IBM MQ client applications which attempt to reconnect
  and reuse a broken connection handle mutliple times.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When a reconnectable IBM MQ client experiences a
  MQRC_CONNECTION_BROKEN error, it then issues a new MQCONNX call
  on the same thread with the HCONN that exists from the previous
  connection.
  
  During this process an error in the MQ client code caused it to
  invalidate some internal information in the client's internal
  channel status table. On subsequent reconnection attempts, this
  status information caused an invalid memory access, which
  generated the FDC file and caused the connection attempt to
  fail.
  

Problem conclusion

• The MQ client code has been corrected to prevent invalidating
  the information in the internal channel status table.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.6
  v9.0 LTS   9.0.0.5
  
  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

  WMQ BASE MULTIP

• Fixed component ID

  5724H7251

Applicable component levels