Entity clustering and JBossCache/EJB3

[andyd]

Hi all.

I originally understood that entity clustering just happened at the cache level with JBossCache. I.e, if you mark an entity with the @Cache annotation, it kept it in memory across each node in the cluster, but they all had to share the same database. I've just done the JBossCache webinar which mentioned an attribute

true

I also see CacheLoaderClass is not present in
ejb3-entity-cache-service.xml and assume the MBean is handling this bit.

So my question is, is my original understanding correct and I need to look at an additional layer to deal with the persistence layer (I have been looking at sequioa) or can I simply appy the appropriate JBossCache config attributes to support independant databases for each node?

Thanks,
Andy.

PS - Great to meet some of you guys in Barcelona!

[andyd]

CacheLoaderShared was that attribute name - the forum didn't appreciate the markup.

Andy.

[kabirkhan]

You need to set up the cache in persistence.xml

http://docs.jboss.org/ejb3/app-server/tutorial/clusteredentity/clusteredentity.html

Then you can define what should be cached using either annotations, or in persistence.xml. See table 2.1:

http://docs.jboss.org/ejb3/app-server/HibernateEntityManager/reference/en/html_single/index.html

[andyd]

Hi Kabir,
Read those, but they don't answer my question, though very informative.

My understanding from them is that you only cache things that don't change often, so not all the entities would actually pass through the cache. Can CacheLoaderShared be used in persistence.xml?

Sounds like I need sequoia to handle HA for persistence.
Thanks,
Andy.