IZ88263: -XSHARECLASSES CACHE RESET CREATES A RANDOMLY SIZED CACHE

APAR status

• Closed as program error.

Error description

• Error Message: JVMSHRC022E Error creating shared memory region
  JVMSHRC336E Port layer error code = -177
  JVMSHRC337E Platform error message: EDC5121I Invalid argument.
  JVMSHRC171E z/OS cannot create cache of requested size: Please
  check your z/OS system BPXPRMxx settings
  JVMSHRC320E Error recovery: destroying shared memory semaphores.
  JVMJ9VM015W Initialization error for library j9shr24(11):
  JVMJ9VM009E J9VMDllMain failed
  .
  Stack Trace: N/A
  .
  

Local fix

• 1.) When using SR8 do not reset a cache using
  -Xshareclasses:reset.
  2.) Do not open SR9 caches using Java 6 SR8.
  3.) Instead of reset, destroy the cache using
  -Xshareclasses:destroy, and then re-create the cache.
  

Problem summary

• When a shared classes cache is reset, a cache of random size may
  be created when using Java 6 SR8.
  This problem only exists in Java 6 SR8.
  The problem can be exposed in 2 ways:
  1.) Calling -Xshareclasses:reset with Java 6 SR8.
  2.) Running Java 6 SR8, with a cache created by Java 6 SR 9 or
  above.
  The problem is only evident to the user if the cache size being
  used exceeds the system limits because an error will occur.
  Also, if the user verifies the size of the shared memory created
  by the JVM they may notice the size is incorrect.
  

Problem conclusion

• This defect will be fixed in:
  6.0.0 SR9
  .
  This problem is fixed in Java 6 SR9. During cache reset the
  correct size will now be used.
  .
  To obtain the fix:
  Install build 20100720 or later
  

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

• R600 PSN

     UP