How can I measure the performance and TCP RTT of my server code?

Question

I created a basic TCP server that reads incoming binary data in protocol buffer format, and writes a binary msg as response. I would like to benchmark the the roundtrip time

Answer 1

Note that TCP performance will go down as the load goes up. If you're going to test under heavy load, you need professional tools that can scale to thousands (or even millions in some cases) of new connection/second or concurrent established TCP connections.

I wrote an article about this on my blog (feel free to remove if this is considered advertisement, but I think it's relevant to this thread): http://synsynack.wordpress.com/2012/04/09/realistic-latency-measurement-in-the-application-layers