Disable Nagle's algorithm, this was exposed by our internal micro benchmark, the streamingInputCall() method happened to have the write-write-read pattern which added 40ms extra delay.

According to our micro benchmark, this change improves the performance, see https://screenshot.googleplex.com/cfxjPGxkgF.png for the previous results, there were 4 out of 6 scenarios had higher latency than netty transport.

https://screenshot.googleplex.com/Rq92tYMvBE.png shows the results after this change, the latencies in all scenarios are less than netty transport.

This commit fixes #60.

okhttp/src/main/java/io/grpc/transport/okhttp/OkHttpClientTransport.java

@@ -208,6 +208,7 @@ public class OkHttpClientTransport implements ClientTransport {
           // We assume the sslSocketFactory will verify the server hostname.
           socket = sslSocketFactory.createSocket(socket, authorityHost, address.getPort(), true);
         }
+        socket.setTcpNoDelay(true);
         source = Okio.buffer(Okio.source(socket));
         sink = Okio.buffer(Okio.sink(socket));
       } catch (IOException e) {