Ws: About the server performance

[millsp]

• [x] I've searched for any related issues and avoided creating a duplicate
  issue.

Description

Hi @lpinca,

I was looking at the different options out there to setup a websocket server on node and I found this benchmark (that looks quite outdated though):

So I wanted to know if you have some (updated) numbers to help me choosing a server.

Thanks

[lpinca]

My suggestion is to run your own benchmarks and choose accordingly. For very small messages of just a few bytes ws is indeed worse than some other existing implementations. That difference shrinks as the message size grows.

[millsp]

I will probably use uWS for the server side then, as I have a lot of small messages to pass. And ws for the client part. Hoping everything works smoothly since they both pass the same test suite.

Thanks!

[lpinca]

For what is worth the bottleneck is not ws but Node.js net.Socket, also if you use a UNIX domain socket instead of a TCP socket on the Node.js side (this is viable if you use a reverse proxy like NGINX) it is almost twice as fast.

[millsp]

Oh that's worth investigating, thanks a lot!

[szmarczak]

For what is worth the bottleneck is not ws but Node.js net.Socket, also if you use a UNIX domain socket instead of a TCP socket on the Node.js side (this is viable if you use a reverse proxy like NGINX) it is almost twice as fast.

After almost a year ago, is this still true? Just asking because I'm curious whether it would make sense to set up an HTTP server on a domain socket and use some sort of domain socket -> IP proxy.

[lpinca]

server.js

'use strict';

const WebSocket = require('ws');
const { createServer } = require('http');

const server = createServer();
const wss = new WebSocket.Server({
  perMessageDeflate: false,
  clientTracking: false,
  server
});

wss.on('connection', function (ws) {
  ws.on('message', function (message) {
    ws.send(message);
  });
  ws.on('close', function () {
    server.close();
  });
});

let options = { port: 8080 };
let message = `server listening on port ${options.port}`;

if (process.argv[2] === '--ipc') {
  message = 'server listening on /tmp/ws.sock';
  options = { path: '/tmp/ws.sock' };
}

server.listen(options, function () {
  console.log(message);
});

client.js

'use strict';

const Sender = require('ws/lib/sender');
const { get } = require('http');
const { randomBytes } = require('crypto');

const bufs = Sender.frame(randomBytes(64), {
  fin: true,
  rsv1: false,
  opcode: 2,
  mask: true,
  readOnly: false
});
const frame = Buffer.concat(bufs);

const options = {
  headers: {
    Connection: 'Upgrade',
    Upgrade: 'websocket',
    'Sec-WebSocket-Key': randomBytes(16).toString('base64'),
    'Sec-WebSocket-Version': 13
  }
};

if (process.argv[2] === '--ipc') {
  options.socketPath = '/tmp/ws.sock';
} else {
  options.port = 8080;
}

const request = get(options);

request.on('upgrade', function (response, socket) {
  let count = 0;
  let bytesRead = 0;

  socket.on('data', function (chunk) {
    bytesRead += chunk.length;

    if (bytesRead === 66) {
      bytesRead = 0;
      count++;

      if (count === 100000) {
        console.timeEnd('100000 * 64');
        socket.end();
      } else {
        socket.write(frame);
      }
    }
  });

  console.time('100000 * 64');
  socket.write(frame);
});

$ node client.js
100000 * 64: 3.757s
$ node client.js --ipc
100000 * 64: 2.055s

[netizen-ais]

$ node client.js
100000 * 64: 3.757s
$ node client.js --ipc
100000 * 64: 2.055s

Is there a similar gain if what you have behind nginx's proxy is the server?

[lpinca]

I did not test it but yes I think it's possible.

[kapooky]

Wouldn't nginx simply front the incoming client tcp connection with a tcp socket and then forward message over a Unix socket to the back end server?

Client -----tcp socket---------> nginx reverse proxy --------unix socket--------> back end server

How would thst be faster than this,:
Client --------tcp socket------> back end

[netizen-ais]

Wouldn't nginx simply front the incoming client tcp connection with a tcp socket and then forward message over a Unix socket to the back end server?

Client -----tcp socket---------> nginx reverse proxy --------unix socket--------> back end server

How would thst be faster than this,:
Client --------tcp socket------> back end

It can't, the proxy will always add a latency penalty, my question was about unix vs tcp socket between nginx proxy and server. That is. There're reasons out there that make the proxy a convenience.