Thanks Scott for the link, just one more question - Can this be applied to web as well? Like having only a remote cache (store) ?
Not at the moment. Web/SFSB clustering currently uses an embedded replicated/distributed/invalidation/local cache. You can however, configure the persistent store to reference a remote cache (i.e. instead of <file-store/>).
<remote-store purge="false" shared="true"><remote-server outbound-socket-binding="remote-cache"/></remote-store>