Synchronizing server-side caches
If multiple JVMs (on one or more machines) perform caching, they need to communicate to keep their caches in sync. You can implement this inter-JVM communication, called remote synchronization. The recommended technology to use is JMS, because it works in a highly scaled or ELB (elastic load-balanced) setup. Alternatively, you can use RMI, which is easier to set up, but does not work in such setups.