@Override
  public void updateClusterName(String oldName, String newName) {
    ConcurrentHashMap<String, Cluster> clusters = getClustersByName();
    clusters.put(newName, clusters.remove(oldName));

    ConcurrentHashMap<String, Set<Host>> clusterHostsMap = getClusterHostsMap();
    clusterHostsMap.put(newName, clusterHostsMap.remove(oldName));

    //TODO metadata update
  }
Attempts to map the host to the cluster via clusterhostmapping table if not already present, and add a host_version
record for the cluster's currently applied (stack, version) if not already present.
@param hostname Host name
@param clusterName Cluster name
@throws AmbariException May throw a DuplicateResourceException.
ambari-server/src/main/java/org/apache/ambari/server/state/cluster/ClustersImpl.java