IJ35969: AN INCREASE IN CPU CONSUMPTION AFTER APPLYING IJ32927

APAR status

• Closed as program error.

Error description

• Error Message: An up to 16-18% rise in the overall CPU
  consumption can be observed after upgrading to IBM SDK 8.0.6.31
  or later maintenance.
  .
  Stack Trace: N/A
  .
  A performance degradation in terms of an increased average
  response-time may also be observed.
  

Local fix

Problem summary

• IJ32927 fixes a functional issue seen with some use cases. The
  fix introduced additional code paths to refresh the last
  user-defined classloader (LUDCL). The performance degradation is
  an unintended consequence of this fix.
  

Problem conclusion

• Please see APAR IJ46956 for the permanent fix for this issue.
  .
  Given that the functional issue reported by IJ32927 may not be
  encountered in all the user-cases,  we are providing an option
  to disable IJ32927, hence avoiding the  performance degradation.
  Users may set "com.ibm.disableLUDCLRefresh=true" to disable
  IJ32927. The default value of this system property is false,
  which means IJ32927 would be enabled by default.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR7 FP5   (8.0.7.5)
  .
  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

  JAVA CLASS LIBS

• Fixed component ID

  620700130

Applicable component levels