Name: PK33052
=============
 
Summary:
   Sporadically long response times can occur.
 
Problem Description:
   With this fix a new property has been introduced to the file 
   <WP_HOME>/shared/app/config/services/CacheManagerService.properties: randomizePercent
   (e.g. cacheinstance.com.ibm.wps.ac.ProtectedResourceCache.randomizePercent=25).
   It can be used to randomize cache entry lifetimes. If all entries into a cache have 
   the same lifetime huge amounts of entries can be evicted at the same time 
   causing high load on the database when reloading entries. The value of this 
   parameter is given as a numeric value in percent. '25' for example means, that 
   all entry lifetimes will be up to 25% higher or lower than the default 
   lifetime (given with the lifetime property). No entry lifetime will be lower 
   than 50% of the default no matter how large the percentage. The default if no 
   value is given is not to randomize entry lifetimes, hence all cache entries 
   will have the default lifetime. No lifetime randomization takes place if the 
   default lifetime is set to infinite. The actual (only randomized) lifetime of 
   a cache entry can be viewed by enabling tracing for class 
   com.ibm.wps.services.cache.DistributedMapCache (time in seconds) and
   com.ibm.wps.services.cache.ThreadlessObjectCache (time in milliseconds).
 
Problem Solution:
   Cache entry lifetimes can be randomized so that not all entries that are loaded at a similar point in time into the cache are discarded at the same moment.
 
Failing Module(s):
   Performance
 
Affected Users:
   All users
 
Version Information:
    Portal Version(s): 5.1.0.4
     Pre-Requisite(s): 
      Co-Requisite(s): ---
 
Platform Specific:
   This fix applies to all platforms.
 
Installation:
   NOTE:  YOU MUST FIRST DOWNLOAD THE UPDATE INSTALLER TOOL IN ORDER TO INSTALL A FIX.
          The Portal Update Installer can be downloaded from the following link:
          http://www.ibm.com/software/genservers/portal/support
 
   1. Create temporary "fix" directory to store the jar file.
   2. Copy jar file to this directory.
   3. Shutdown WebSphere Portal.
   4. Follow the fix installation instructions that are packaged with
      the Portal Update Installer on how to install the fix.
   5. Restart WebSphere Portal.
   6. The temporary directory may be removed.
 
Un-Installation:
   NOTE:  FIXES MUST BE REMOVED IN THE ORDER THEY WERE APPLIED.  DO NOT REMOVE
          A FIX UNLESS ALL FIXES APPLIED AFTER IT HAVE FIRST BEEN REMOVED.
          YOU MAY REAPPLY ANY REMOVED FIX.
 
   1. Shutdown WebSphere Portal.
   2. Follow the instructions that are packaged with the
      Portal Update Installer on how to uninstall the fix.
   3. Restart WebSphere Portal.