mqtt-memory-leak.js

const mqtt = require('mqtt');
const _ = require('lodash');
const memwatch = require('memwatch-next');
const util = require('util');
const setTimeoutPromise = util.promisify(setTimeout);

memwatch.on('leak', (info) => {
  console.error('Memory leak detected:\n', info);
});

const NUMBER_OF_CLIENTS = parseInt(process.env.NUMBER_OF_CLIENTS, 10) || 5;

console.log('NUMBER_OF_CLIENTS: ', NUMBER_OF_CLIENTS)

_.times(NUMBER_OF_CLIENTS, async (n) => {
  await setTimeoutPromise(n * 500);

  console.log('connecting client')
  const client = mqtt.connect('mqtt://broker.hivemq.com');

  client.subscribe(`/blah`, err => {
    if (err) {
      console.error(err, 'Subscription error')
    }
  })

  client.on('error', err => {
    console.error(err, 'Error with mqtt client');
  })

  client.once('connect', () => {
    console.log(`client connected`)
  });
});