Does Liferay support clustering?
Yes, Liferay does support clustering. In general, it is handled as you would any other clustered environment. Usually, a load balancer is put in front of a farm of servers. Objects in Liferay are cached per server in the server cache. Liferay provides support for Ehcache so that if any object is modified, a broadcast message is sent out to all servers in the cluster to invalidate their caches and retrieve the updated object from the database. The configuration for Ehcache in a clustered environment is controlled in 3 properties files: • portal.properties – Search for the “Ehcache” section and follow the documentation in the comments • ehcache.single.vm.config.location – Properties for caching objects that do not need to be synchronized across the cluster • ehcache.multi.vm.config.location – Properties for caching objects that do need to be synchronized across the cluster The config files are loaded from the Java classpath.
