PM81274: When the same key is fetched by many threads, there can be a performance bottleneck in the locking function.

APAR status

• Closed as program error.

Error description

• The response time of get() operations for a key decreases as
  more threads access the same key.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  Users of WebSphere eXtreme Scale who use    *
  *                  OPTIMISTIC or PESSIMISTIC locking and       *
  *                  access the same key concurrently with       *
  *                  multiple threads                            *
  ****************************************************************
  * PROBLEM DESCRIPTION: In a scenario where the same key is     *
  *                      accessed concurrently by multiple       *
  *                      threads, performance degrades.          *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The locking code was updated to use features in Java 5, which
  improve concurrency when the same object is accessed by
  multiple transactions.
  

Problem conclusion

• An interim fix is available for this APAR.
  

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

  WS EXTREME SCAL

• Fixed component ID

  5724X6702

Applicable component levels

• R711 PSY

     UP

• R850 PSY

     UP

• R860 PSY

     UP