public static boolean isClusteringEnabled() {
        return JiveGlobals.getXMLProperty(CLUSTER_PROPERTY_NAME, false);
    }
Returns true if clustering support is enabled. This does not mean
that clustering has started or that clustering will be able to start.

@return true if clustering support is enabled.
xmppserver/src/main/java/org/jivesoftware/openfire/cluster/ClusterManager.java