IJ29286: NOT SETTING THE "IBM.SWAPLF" PROPERTY, OR SETTING TO FALSE, DEGRADES PERFORMANCE

APAR status

• Closed as program error.

Error description

• Error Message: IBM Health Center profiles shows up the hottest
  methods being invoked from
  sun/nio/cs/ext/ExtendedCharset.isSwapLF().
  System.getProperty
  - System.getProperty (100%)
  - Boolean.getBoolean (100%)
     - GetBooleanAction.run (100%)
         - ExtendedCharsets.isSwapLF (100%)
  .
  Stack Trace: N/A
  .
  

Local fix

Problem summary

• sun/nio/cs/ext/ExtendedCharset.isSwapLF() method is expected to
  check for the change of value of ibm.swapLF property every time
  as it can get set any time programmatically. This makes it a
  performance bottleneck. Prior to this APAR, if the value of the
  ?ibm.swapLF? property was set as ?true?, either through the
  command line or programmatically,  it was cached  and a change
  to it did not take effect. However, if the value was not set, or
  set explicitly as ?false?, it was repeatedly checked for by
  ExtendedCharset.isSwapLF().
  

Problem conclusion

• This APAR introduces a new value for the ?ibm.swapLF? property,
  called ?disable?. The new value is to be used if the user does
  not want to enable the swapLF functionality at all. Note that
  this is different from setting the value as ?false?, or to not
  setting it explicitly, in which cases it must be possible to
  change it to ?true? by setting the property programmatically.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR6 FP25  (8.0.6.25)
  .
  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

• R800 PSY

     UP