PK70944: Performance: Excessive invalidation messages on GroupCache

6.1.0.1 Download: WebSphere Portal and Web Content Management V6.1, fix pack 1
6.1.0.2 Download: WebSphere Portal and Web Content Management V6.1, fix pack 2
6.1.0.3 Download: WebSphere Portal and WCM V6.1 fix pack 3, 6.1.5 feature pack
6.1.0.4 Download: WebSphere Portal and WCM V6.1.0 fix pack 4 & 6.1.5 fix pack 1
6.1.0.5 Download: WebSphere Portal and WCM V6.1.0 fix pack 5
6.1.0.6 Download: WebSphere Portal and WCM V6.1.0 fix pack 6

APAR status

• Closed as program error.

Error description

• During IBM Performance testing, the following issue was
  discovered and is addressed in the fix for this APAR:
  
  Problem in cache invalidations on the GroupCache preventing
  proper scalability. Tracing all of the DRS messages due to
  cache invalidation showed many on this cache:
  Invalidation Events
  24801 invalidations on Cache
  ws/com.ibm.wps.ac.groupmanagement.GroupCache
  ...and several other caches...
  By explicitly invalidating entries in this cache without
  checking if there's an entry in this cache, this creates a
  performance problem  because those invalidations are sent to
  the peer nodes, and there's significant overhead for this.
  
  The sources of the invalidations are these two methods
  within com.ibm.wps.ac.impl.PACGroupManagementServiceImpl:
  - invalidatePeerGroupCache
  - invalidateCacheForPrincipal
  

Local fix

Problem summary

• During IBM Performance testing, the following issue was
  discovered and is addressed in the fix for this APAR:
  
  Problem in cache invalidations on the GroupCache preventing
  proper scalability. Tracing all of the DRS messages due to cache
  invalidation showed many on this cache:
  Invalidation Events
  24801 invalidations on Cache
  ws/com.ibm.wps.ac.groupmanagement.GroupCache
  ...and several other caches...
  By explicitly invalidating entries in this cache without
  checking if there's an entry in this cache, this creates a
  performance problem  because those invalidations are sent to the
  peer nodes, and there's significant overhead for this.
  
  The sources of the invalidations are these two methods within
  com.ibm.wps.ac.impl.PACGroupManagementServiceImpl:
  - invalidatePeerGroupCache
  - invalidateCacheForPrincipal
  

Problem conclusion

• Only invalidate cache if there are entries in the cache for the
  object.
  
  Failing Module(s):
     Portal Access Control
  
  Affected Users:
     All users
  
  Version Information:
      Portal Version(s): 6.1.0.0
       Pre-Requisite(s):
        Co-Requisite(s): ---
  
  Platform Specific:
     This fix applies to all platforms.
  
  A fix is available from Fix Central:
  
  http://www.ibm.com/eserver/support/fixes/fixcentral/swgquickorde
  r?apar=PK70944&productid=WebSphere%20Portal&brandid=5
  
  You may need to type or paste the complete address into your Web
  browser.
  

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

  WEBSPHERE PORTA

• Fixed component ID

  5724E7600

Applicable component levels

• R610 PSY

     UP