I have two questions regarding the messaging cluster. I could not find the answer in the documentation. This is what I need to achieve: Jboss messaging cluster to provide seamless fail-over for the publishing and subscribing clients. Persistence and durable subscription are not needed. In other words, an unreliable but highly available replicated topic. 1. HA and load-balance without persistence Messaging doc says that a shared DB is required for the cluster to work. Before that it states that the post-office will not work without a DS. I am aware that embedded DB may be configured to avoid persistence until a threshold of memory usage is hit. My question related to this: - Would I need the shared DB even if I use these clustered post-offices to host non-persistent (non-durable) subscriptions, that is, is it used to manage the cluster information as well? - Is it OK to use HSQLDB or Derby if the above is not true? 2. Recovery from a cluster restart Since Jboss messaging relies on a clustered ConnectionFactory registered in a clustered JNDI to provide the failover mechanism, would the client need to re-lookup JNDI and reopen connections and sessions to get back in business? This seems unnecessary since all participating post-offices seem to be bound to a pre-defined host and port, but then I am not sure how it is different from a clustered Stateless session bean. thanks kapil View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4128535#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...