public static synchronized void startup() {
        if (isClusteringEnabled() && !isClusteringStarted()) {
            initEventDispatcher();
            CacheFactory.startClustering();
        }
    }
Starts the cluster service if clustering is enabled. The process of starting clustering
will recreate caches as distributed caches.
xmppserver/src/main/java/org/jivesoftware/openfire/cluster/ClusterManager.java