Is it possible to achieve session replication just using standalone with full-ha profile on the nodes in an UN-clustered environment ? Why does infinispan need a cluster environment ?
Session replication in an application server happens is your application is cluster-aware (f.e. if you include a stanza in your web.xml). If you don't make a cluster-aware application the cluster service itself won't start. You can see that, however, Infinispan cluster is available (and so its caches) but in a managed environment (inside an application server) you cannot expect a replication of data if you don't make a clusterable application.