Method helloRpc

src/RegionClient.java:2218–2233

Sends the "hello" message needed when opening a new connection. This message is immediately followed by a GetProtocolVersionRequest so we can learn what version the server is running to be able to talk to it the way it expects. @param chan The channel connected to the server we need to hands

(final Channel chan, final ChannelBuffer header)

   * @param header The header to use for the handshake.
   */
  private void helloRpc(final Channel chan, final ChannelBuffer header) {
    LOG.debug("helloRpc for the channel: {}", chan);
    Callback<Object, Exception> errorback = new Callback<Object, Exception>() {

      @Override
      public Object call(final Exception e) throws Exception {
        LOG.info("helloRpc failed. Closing the channel:" + chan, e);
        Channels.close(chan);
        return e;
      }
    };
    final GetProtocolVersionRequest rpc = new GetProtocolVersionRequest();
    rpc.getDeferred().addBoth(new ProtocolVersionCB(chan))
                     .addErrback(errorback);
    Channels.write(chan, ChannelBuffers.wrappedBuffer(header, encode(rpc)));
  }

  /**
   * Fetch the protocol version from the region server