Menu

This is documentation for the next version of Grafana k6 documentation. For the latest stable release, go to the latest version.

Documentationbreadcrumb arrow Grafana k6breadcrumb arrow Examplesbreadcrumb arrow WebSockets
Open source

WebSockets

Here’s a load test for the QuickPizza WebSocket API, available on https://quickpizza.grafana.com/ws.

Multiple VUs connect using a VU-indexed user name, and send random messages.

Each VU receives messages sent by all other VUs.

JavaScript 
import { randomString, randomIntBetween } from 'https://jslib.k6.io/k6-utils/1.2.0/index.js';
import ws from 'k6/ws';
import { check, sleep } from 'k6';

const sessionDuration = randomIntBetween(3000, 6000); // user session between 3s and 6s

export const options = {
  vus: 10,
  iterations: 10,
};

export default function () {
  const url = `wss://quickpizza.grafana.com/ws`;
  const params = { tags: { my_tag: 'my ws session' } };
  const user = `user_${__VU}`;

  const res = ws.connect(url, params, function (socket) {
    socket.on('open', function open() {
      console.log(`VU ${__VU}: connected`);

      socket.send(JSON.stringify({ msg: 'Hello!', user: user }));

      socket.setInterval(function timeout() {
        socket.send(
          JSON.stringify({
            user: user,
            msg: `I'm saying ${randomString(5)}`,
            foo: 'bar',
          })
        );
      }, randomIntBetween(1000, 2000)); // say something every 1-2 seconds
    });

    socket.on('ping', function () {
      console.log('PING!');
    });

    socket.on('pong', function () {
      console.log('PONG!');
    });

    socket.on('close', function () {
      console.log(`VU ${__VU}: disconnected`);
    });

    socket.on('message', function (message) {
      const data = JSON.parse(message);
      console.log(`VU ${__VU} received message: ${data.msg}`);
    });

    socket.setTimeout(function () {
      console.log(`VU ${__VU}: ${sessionDuration}ms passed, leaving the website`);
      socket.send(JSON.stringify({ msg: 'Goodbye!', user: user }));
    }, sessionDuration);

    socket.setTimeout(function () {
      console.log(`Closing the socket forcefully 3s after graceful LEAVE`);
      socket.close();
    }, sessionDuration + 3000);
  });

  check(res, { 'Connected successfully': (r) => r && r.status === 101 });
  sleep(1);
}