code: private static void registerDnProtocolAddress(AvatarZooKeeperClient zk,
        Configuration originalConf, Configuration conf, boolean toOverwrite)
        throws UnsupportedEncodingException, IOException {
      LOG.info("Updating Service Address information in ZooKeeper");
      registerSocketAddress(zk,
          originalConf.get(NameNode.DATANODE_PROTOCOL_ADDRESS),
          conf.get(NameNode.DATANODE_PROTOCOL_ADDRESS), toOverwrite);
      registerAliases(zk, conf, FSConstants.DFS_NAMENODE_DN_ALIASES,
          conf.get(NameNode.DATANODE_PROTOCOL_ADDRESS), toOverwrite);
    }
docs: Registers the datanode protocol address in the zookeeper