PM43269: EXCEPTIONDESTINATIONHANDLERIMPL IS NOT THREAD SAFE. THIS MAY CAUSE UNDELIVERED MESSAGES MOVED TO INCORRECT EXCEPTION DESTIN

8.0.0.2: WebSphere Application Server V8.0 Fix Pack 2
8.0.0.3: WebSphere Application Server V8.0 Fix Pack 3
8.0.0.4: WebSphere Application Server V8.0 Fix Pack 4
8.0.0.5: WebSphere Application Server V8.0 Fix Pack 5
8.0.0.6: WebSphere Application Server V8.0 Fix Pack 6
8.0.0.7: WebSphere Application Server V8.0 Fix Pack 7
8.0.0.8: WebSphere Application Server V8.0 Fix Pack 8
8.0.0.9: WebSphere Application Server V8.0 Fix Pack 9
8.0.0.10: WebSphere Application Server V8.0 Fix Pack 10
8.0.0.11: WebSphere Application Server V8.0 Fix Pack 11
8.0.0.12: WebSphere Application Server V8.0 Fix Pack 12
8.0.0.13: WebSphere Application Server V8.0 Fix Pack 13
8.0.0.14: WebSphere Application Server V8.0 Fix Pack 14
8.0.0.15: WebSphere Application Server V8.0 Fix Pack 15

APAR status

• Closed as program error.

Error description

• Error Description:
  ------------------
  In scenarios where a bus is configured with one or more custom
  exception destinations, undelivered messages may end up routed
  to incorrect exception destinations. This may go unnoticed as
  no exceptions or error codes are thrown. This is due to an
  error in the code that makes the exception destination handler
  non thread-safe.
  
  One example scenario is a setup where a custom exception
  destination is FULL. The messages that have failed on delivery
  would be redirected to the custom exception destination after
  completing the defined number of retry attempts. Since the
  custom exception destination is FULL, the message would have
  to be redirected to the system exception destination. Please
  note that the failure on delivery may happen in three
  circumstances -
  1. Failure to put the message on the intended destination
  due to reasons such as the destination is full;
  2. Failure to consume the message by the MDBs;
  3. Failure in mediation.
  
  Without the fix, the exception destination handler set to the
  custom exception destination may be overwritten by another
  thread, causing the message to bypass the custom exception
  destination and end up directly in the system exception
  destination.
  
  With the fix in place, access to the exception destination
  handler is serialized and made thread-safe.
  
  Please note that this is a silent bug. No exceptions and error
  codes are reported.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server                                      *
  *                  v8.0.                                       *
  ****************************************************************
  * PROBLEM DESCRIPTION: Undelivered messages may bypass primary *
  *                      exception destination before landing up *
  *                      in                                      *
  *                      system exception destination.           *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  A message failing on delivery is forwarded to the primary
  exception destination after the "Maximum Failed Delivery" limit
  is reached. A bug in exception destination handler code causes
  some of the undeliverable messages bypass the primary exception
  destination and end up in the secondary exception destination
  (usually set to the system exception destination). The defect
  would occur in the scenarios where the primary exception
  destination fails to accept undelivered messages.
  One example scenario is a setup where the custom exception
  destination is FULL. Failure in delivering a message may happen
  in three circumstances:
  1. Failure to put the message on the intended destination due to
  reasons such as the destination is full;
  2. Failure to consume the message by the MDBs;
  3. Failure in mediation.
  The messages that have failed on delivery would be redirected to
  the custom exception destination after the "Maximum Failed
  Delivery" limit is reached. Failure in accepting the undelivered
  message is reported with the warning code CWSIP0291W in the
  trace. Since the custom exception destination is FULL, the
  message would have to be redirected to the system exception
  destination.
  However, the exception destination handler set to the custom
  exception destination may be overwritten by another thread,
  causing the message to bypass the custom exception destination
  and end up directly in the system exception destination. This is
  due to an error in the code that makes the exception destination
  handler non thread-safe.
  This is a silent bug. No exceptions and error codes are
  reported. Therefore, the problem may go unnoticed.
  

Problem conclusion

• The code has been fixed by synchronizing the critical section
  using a mutable java Object. This ensures access to the
  exception destination handler is serialized and made thread-
  safe.
  
  The fix for this APAR is currently targeted for inclusion in
  fix pack 8.0.0.2  Please refer to the Recommended Updates page
  for delivery information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

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

  WEBS APP SERV N

• Fixed component ID

  5724H8800

Applicable component levels

• R800 PSY

     UP