@Deprecated
  public String getClusterKey() {
    return conf.get(HConstants.ZOOKEEPER_QUORUM) + ":" + conf.get(HConstants.ZOOKEEPER_CLIENT_PORT)
      + ":"
      + conf.get(HConstants.ZOOKEEPER_ZNODE_PARENT, HConstants.DEFAULT_ZOOKEEPER_ZNODE_PARENT);
  }
Get the zk based cluster key for this cluster.
@deprecated since 2.7.0, will be removed in 4.0.0. Now we use connection uri to specify the
            connection info of a cluster. Keep here only for compatibility.
@see #getRpcConnnectionURI()
@see #getZkConnectionURI()
hbase-testing-util/src/main/java/org/apache/hadoop/hbase/HBaseTestingUtility.java