In Mule 3.2 a group of stand-alone Mule instances can be configured to act as a cluster. One or more applications runs in each instance – or node – and the cluster processes requests as if a single unit. A node goes down, the application is still running; the more nodes, the more throughput. And the more nodes, the greater the headache. How many Putty sessions are you already running, let alone a group of new sessions to manage all those nodes?