code: private CoronaTaskTrackerProtocol createClient(String host, int port)
      throws IOException {
      String staticHost = NetUtils.getStaticResolution(host);
      InetSocketAddress s = null;
      InetAddress  inetAddress = null;
      byte[] byteArr = null;
      if (staticHost != null) {
        inetAddress = InetAddress.getByName(staticHost);
      } else {
        byteArr = Utilities.asBytes(host);
        if ( byteArr == null) {
          inetAddress = InetAddress.getByName(host);
        }
        else {
          inetAddress = InetAddress.getByAddress(byteArr);
        }
      }
      s = new InetSocketAddress(inetAddress, port);
      LOG.info("Creating client to " + 
        (staticHost != null ? staticHost : host) + ":" + s.getPort());
      long connectTimeout =
        conf.getLong(CoronaJobTracker.TT_CONNECT_TIMEOUT_MSEC_KEY, 10000L);
      int rpcTimeout =
        conf.getInt(CoronaJobTracker.TT_RPC_TIMEOUT_MSEC_KEY, 60000);
      return RPC.waitForProxy(
        CoronaTaskTrackerProtocol.class,
        CoronaTaskTrackerProtocol.versionID,
        s,
        conf,
        connectTimeout,
        rpcTimeout);
    }
docs: Connect to the task tracker and get the RPC client.
  @param host The host.
  @param port the port.
  @return The RPC client.
  @throws IOException