c-tcp-latency
Program to measure TCP RTT latency between a server and a client.
The program will measure cycles it took to perform a send and how many cycles it took from after sending to complete receive.
If you want to measure time instead of cycles, just lscpu the frequency of your machines and derive the time from the cycles calculated.
Otherwise, you could make use of one of my other tools, namely rust-tcp-io-perf that measures either latency or bandwidth of a connection.
Usage
You will need to run the server and the client separately, on the two machines you want to benchmark the latency between.
Open a terminal on both machines (either directly or via SSH) and clone the repo, cd into the src folder and run make to compile.
Once compiled, first start up the server machine, by staying in the src folder and running the command
./server -p <port> -n <n_bytes>
where <port> is the port you want to listen on and <n_bytes> the size of the messages you will receive.
Similarly, to run the client, from the src folder, run
./client -a <server_address> -p <port> -n <n_bytes>
Where <server_address> is the addres (or hostname) of the server machine, <port> the same port you ran server with and <n_bytes> the same used for server (size of the messages you will send).
The client program, once done, will printo out results for 1M iterations of latency measure, in the format (<send>, <receive>), where <send> is the time it took to perform the send, and <receive> the time it took from after the send to right after the receive is completed.
./server -p 9994 -b 10 -a 10.0.6.1
./client -a 10.0.6.1 -p 9994 -b 10
to HDR hist
You can use the inner Rust program to_HDRhist to transform the ugly c output to a nicer HDRhist (https://github.com/utaal/hdrhist-rust) output with ccdfs.