PM83293: LOCK CONTENTION IN CALENDARDESERIALIZER

APAR status

• Closed as program error.

Error description

• During performance testing, we noticed a signifcant amount
  of lock contention in CalendarDeserializer
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  IBM WebSphere Application Server V8.5       *
  *                  users of JAX-RPC Web Service applications   *
  ****************************************************************
  * PROBLEM DESCRIPTION: While JAX-RPC webservices working       *
  *                      under heavy load on Solaris machines,   *
  *                      CPU usage was lower than expected.      *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  There's a signifcant amount of lock contention. The
  CalendarDeserializer objects share a static SimpleDateFormat
  object which is not thread safe.  To protect it,
  CalendarDeserializer implements synchronization around it,
  which is where the lock contention was happening.
  

Problem conclusion

• Instead of using a static SimpleDateFormat, which was causing
  lock contention among threads, we create ThreadLocal versions
  of the objects. After patching the CalendarDeserializer, the
  problem, the lock contention on this method, was resolved.
  
  The fix for this APAR is currently targeted for inclusion in
  fix pack 8.5.5.0. 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

• R850 PSY

     UP