PM35274: LOCKTIMEOUTEXCEPTIONS WHEN USING THE WEBSPHERE XS DYNAMIC CACHE PLUGIN.

PM37461; 7.1.0.2: FIX THREAD SAFETY ISSUE WHEN RUNNING SAME QUERY CONCURRENTLY
Download WebSphere eXtreme Scale V6.1.0 Fix Pack 5 compatibility fix

APAR status

• Closed as program error.

Error description

• When using the WXS dynamic cache plugin, heavy simultaneous load
  may result in the ORB threads becoming exhausted, resulting in
  LockTimeoutExceptions.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of the WebSphere eXtreme Scale    *
  *                  Dynamic cache provider.                     *
  ****************************************************************
  * PROBLEM DESCRIPTION: See "Error Description"                 *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  In WXS, a Put() operation requires a getForUpdate(), which
  locks the entry, followed by the put().  This activity
  takes place on the WXS client, resulting in multiple
  "hops" to the WXS server.   Under significant load the number
  of ORB threads on the WXS server may become exhausted with
  threads attempting to get a specific lock.   When this happens
  the client process that holds the lock will be unable to
  complete the getForUpdate()/Put() operations until an ORB
  thread becomes available.
  

Problem conclusion

• The solution to this issue is to move the getForUpdate()/Put()
  activities into an Agent so that they will take place on the
  WXS server.   This eliminates the multiple "hops" and
  resulting ORB thread contention.
  

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

  XD EXTREME SCAL

• Fixed component ID

  5724J3402

Applicable component levels

• R710 PSY

     UP