JBoss AS clustering is built on JGroups - a toolkit for reliable multicast communication between AS server nodes on an existing computer network. It can be used to create groups of processes whose members can send messages to each other. JGroups enables developers to create reliable multipoint (multicast) applications where reliability is a deployment issue. JGroups also relieves the application developer from implementing this logic themselves. This saves significant development time and allows for the application to be deployed in different environments without having to change code. The following are the key features of JGroup.