Ehcache settings Alfresco

http://wiki.alfresco.com/wiki/Repository_Cache_Configuration#Overriding_the_EHCache_Defaults

org.alfresco.repo.cache.EhCacheTracerJob

increasing l2 cache



low hit ratios to be fine tuned

http://docs.alfresco.com/4.0/index.jsp?topic=%2Fcom.alfresco.enterprise.doc%2Fconcepts%2Fcache-memorysettings.html
http://docs.alfresco.com/4.0/index.jsp?topic=%2Fcom.alfresco.enterprise.doc%2Fconcepts%2Fcache-indsettings.html

http://docs.alfresco.com/4.0/index.jsp?topic=%2Fcom.alfresco.enterprise.doc%2Ftasks%2Fcaches-trace.html


Each cache is configured in an XML block with the following parameters:

name
    The name attribute is the name of the cache and generally indicates the type of objects being cached.

maxElementsInMemory
    The maxElementsInMemory controls the maximum size of the cache. This value can be changed to tune the size of the cache for your system. Ehcache caches are implemented using a linked-map system, which means that memory is only required for objects that are actually in memory. If you set the maxElementsInMemory to a high value, it will not automatically allocate that number of slots. Instead, they are added to the linked list as required. When maxElementsInMemory is reached, the cache discards the oldest objects before adding new objects.

timeToIdleSeconds - timeToLiveSeconds
    timeToIdleSeconds and timeToLiveSeconds control the automatic timeout of cached objects.

overflowToDisk
    overflowToDisk controls whether the cache should overflow to disk rather than discarding old objects.

A typical trace is as follows:

The criteria are:

    (MissCount - CurrentCount) must be as low as possible.

    (HitCount/MissCount) must be as high as possible.

Estimated maximum size affects the permanent memory taken up by the cache. If the caches grow too large, they may crowd out transient session memory and slow down the system. It is useful to have this running, on occasion, to identify the caches with a low HitCount/MissCount ratio.