Recently I've been working on Hibernate Search clustering. Hibernate Search will have the ability to work in a master / slave mode. Every node has a local copy of the index and can read it (ie query it). When an update is required (actually when a transaction scoped list of updates are required) by a node, a message is sent to a master node responsible to update the master index. On a regular basis, each node acquires a copy of the master index in local to stay up to day asynchronously. My first implementation involves JMS, but one could imagine using: - JBoss Messaging standalone in headless mode (when it's done) - a servlet controller receiving http requests - whatever you want Thoughts? The project moves slowly from a library to a library + infrastructure project. The focus will stay on the library side, but I am think of having some helpers to build the server side (ie build a ready to deploy EAR or WAR)