PI44958: Exceptions when requestTiming is re-enabled

8.5.5.7: WebSphere Application Server V8.5.5 Fix Pack 7
8.5.5.8: WebSphere Application Server V8.5.5 Fix Pack 8
8.5.5.9: WebSphere Application Server V8.5.5 Fix Pack 9
8.5.5.10: WebSphere Application Server V8.5.5 Fix Pack 10
8.5.5.11: WebSphere Application Server V8.5.5 Fix Pack 11
8.5.5.12: WebSphere Application Server V8.5.5 Fix Pack 12
8.5.5.13: WebSphere Application Server V8.5.5 Fix Pack 13
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.15: WebSphere Application Server V8.5.5 Fix Pack 15
8.5.5.17: WebSphere Application Server V8.5.5 Fix Pack 17
8.5.5.20: WebSphere Application Server V8.5.5.20
8.5.5.18: WebSphere Application Server V8.5.5 Fix Pack 18
8.5.5.19: WebSphere Application Server V8.5.5 Fix Pack 19
8.5.5.16: WebSphere Application Server V8.5.5 Fix Pack 16
8.5.5.21: WebSphere Application Server V8.5.5.21

APAR status

• Closed as program error.

Error description

• When in-flight requests are present, adding and removing
  methods in FastList.java throws ArrayIndexOutOfBounds
  exceptions when the request timing feature is stopped or
  re-enabled.
  
  These errors are seen because of the following reasons.
  
  1) Fast list reset operation is not correctly handled, so
  the index value used by the add method can be out of range
  when the feature is re-enabled.
  
  2) Feature removal operation with in-flight requests can
  result in an index value being passed to the remove method
  of fast list which is no longer valid.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server Liberty Profile - Serviceability     *
  *                  Tools                                       *
  ****************************************************************
  * PROBLEM DESCRIPTION: Exceptions seen when requestTiming is   *
  *                      stopped or re-enabled                   *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  ArrayIndexOutOfBounds exceptions are seen in requests that are
  in progress when the requestTiming feature is dynamically
  stopped or re-enabled.
  

Problem conclusion

• In flight requests can result in stale index values being used
  for an internal data structure, these values become stale as the
  data structure gets re-initialized on stopping and re-enabling
  the feature. Code was modified to handle these stale values
  appropriately.
  
  The fix for this APAR is currently targeted for inclusion in fix
  pack 8.5.5.7.  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

  WAS LIBERTY COR

• Fixed component ID

  5725L2900

Applicable component levels

• R855 PSY

     UP