//
// should be just one set, this is just to find out if this instance
// is cluster-enabled and the cluster supports JMX
//
Set clusters = mBeanServer.queryMBeans(new ObjectName("*:type=Cluster,host=" + hostName), null);
Set membership = mBeanServer.queryMBeans(membershipOName, null);
if (clusters != null && clusters.size() > 0 && membership != null && membership.size() > 0) {
ObjectName clusterOName = ((ObjectInstance) clusters.iterator().next()).getObjectName();
cluster = new Cluster();
cluster.setName(JmxTools.getStringAttr(mBeanServer, clusterOName, "clusterName"));