public static String getInstanceName(DataNodeId dataNodeId) {
    return getInstanceName(dataNodeId.getHostname(), dataNodeId.getPort());
  }
Construct and return the instance name for given data node id
@param dataNodeId the {@link DataNodeId} object.
@return the constructed instance name.
ambry-clustermap/src/main/java/com/github/ambry/clustermap/ClusterMapUtils.java