public void stop() {
    CloseableUtils.closeQuietly(znode);
    CloseableUtils.closeQuietly(instancesCache);
    CloseableUtils.closeQuietly(zooKeeperClient);
  }
Get the ensemble server addresses from the configuration. The format is: host1:port,
host2:port..

@param conf configuration
llap-client/src/java/org/apache/hadoop/hive/registry/impl/ZkRegistryBase.java