code: public static InetSocketAddress getAddress(Configuration conf) {
      InetSocketAddress u = NameNode.getClientProtocolAddress(conf);
      int port = conf.getInt(AvatarNode.DFS_AVATARNODE_PORT_KEY, u.getPort() + 1);
      return new InetSocketAddress(u.getAddress(), port);
    }
docs: Returns the hostname:port for the AvatarNode. The default
  port for the AvatarNode is (the client RPC port
  of the underlying namenode + 1)