IV99741: JAVA SYNCHRONIZATION IMPROVEMENTS

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: N/A
  .
  

Local fix

Problem summary

• When a large number of threads try to acquire a Java monitor
  (high contention), throughput of the application can suffer.
  

Problem conclusion

• In the JVM, the synchronization algorithm has been modified in
  order to better handle high contention scenarios. Also, two new
  command line options have been added to the JVM:
  -Xthr:fastNotify and -Xthr:noFastNotify. Presently,
  -Xthr:noFastNotify is the default setting in the JVM. If high
  contention is seen when the Java wait/notify features are
  aggressively used, then -Xthr:fastNotify can be used to resolve
  the issue.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR5       (8.0.5.0)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the available
  Service Refreshes and Fix Packs can be found at:
             https://www.ibm.com/developerworks/java/jdk/
  

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

  J9 COMMON CODE

• Fixed component ID

  620700127

Applicable component levels

• R270 PSY

     UP