Centralized cache server. (Ehcache or Hazelcast)

Question

Currently we have 2 app severs, each has application level cache and has centralized database server. To keep both servers app cache in sync we have set up JMS broker in between. On cache clear on one server which sends message to JMS, since other is registered so it will get the message and clears the perticular entry based on message content.

Since this messaging system adds latency in clearing the cache entry, for some amount of time there will be inconsistency between application level caches.

So we thought of having centralized cache server to avoid all this extra work to done to keep all caches in sync.

We are thinking of using Ehcache/Terracotta or Hazelcast, these cache hold resultsets, locks info, and some system specific varaibles.

Please suggest best cache solution for us.

Answer 1

I probably can't suggest the best solution for you but I'll try to give some ideas:

Hazelcast: offers very easy to use distributed map (and lot's of other things worth to have a look at - distributed SQL Query is very neat):

Map<String, Object> map = Hazelcast.getMap("xxx");

and you are done. Work on the map using standard API's. Hazelcast config/setup is quite easy (compared to Ehcache/TC). The monitoring webapp is also easy to use and helpful but there are things missing. Performance should be more than sufficient for a small cluster (like your 2 servers).

Ehcache/Terracotta: would introduce a new infrastructure component to your setup (Terracotta Server) - may be a downside. Using this setup is in my experience quite intense in terms of things to learn and try out. The promise is enterprise class level performance and monitoring facilities.

If you don't have extreme high performance requirements I personally would go for Hazelcast and avoid the complexity of Ehcache/TC.

Answer 2

We have been using centralized Memcached server (as Hibernate 2nd level cache and other caching requirement) and its working well for us. We are using Memcached with XMemcached client and so far its working without any problem.