9.5.2. Replicated Caches With All Caches Sharing The Same Store

The following figure shows 2 JBoss Cache instances sharing the same backend store:

Both nodes have a cache loader that accesses a common shared backend store. This could for example be a shared filesystem (using the FileCacheLoader), or a shared database. Because both nodes access the same store, they don't necessarily need state transfer on startup. Rather, the FetchInMemoryState attribute could be set to false, resulting in a 'cold' cache, that gradually warms up as elements are accessed and loaded for the first time. This would mean that individual caches in a cluster might have different in-memory state at any given time (largely depending on their preloading and eviction strategies).

When storing a value, the writer takes care of storing the change in the backend store. For example, if node1 made change C1 and node2 C2, then node1 would tell its cache loader to store C1, and node2 would tell its cache loader to store C2.