PPM cache overview
This topic introduces PPM cache.
About PPM cache
PPM administrators can tune PPM caches such as table component, request type search fields, and validation values, from the <PPM_HOME>/conf/cache.conf directory. You can view its cache statistics in the CacheManager Statistics report in Server Tools of PPM Workbench.
There is another type of caches in PPM (the Hibernate second level cache). However, this is an internal cache that cannot be configured or tuned. Its configuration is defined in the <SERVER_HOME>\deploy\itg.war\WEB-INF\conf\ehcache.xml directory and it should not be tampered with.
Cache statistics report
This section introduces the CacheManager Statistics report.
The CacheManager Statistics report includes the following information for each cache:
Hits, misses, and hit rate (the higher the hit rate, the better)
The number of cache flushes
Cache flushes are broken down by the categories "old", "idle", "soft reference reclaimed", and "max cache size reached"
The average load time to load an object from database when it is not in the cache
The number of staleness checks performed
The maximum cacheable objects (cache size), cached object count, and maximum idle time
Whether the cache is distributed or not
If it is distributed, removing an object from the cache in any node of the PPM cluster will send a message to all the other cluster nodes to remove that object from their caches.