Bull queue concurrency example

concurrentQueue.js

import Queue from 'bull'; // Using https://github.com/OptimalBits/bull/tree/v3.4.8

const url = 'redis://127.0.0.1:6379';
const prefix = 'queue-app';

export const createQueue = name => new Queue(name, url, {
  prefix: `${prefix}:jobs`,
  defaultJobOptions: {
    backoff: { type: 'linear' },
    attempts: 20,
  },
  settings: {
    backoffStrategies: {
      linear: attemptsMade => attemptsMade * 10 * 1000,
    },
  },
});

const queue = createQueue('ConcurrentQueue');
const doSomethingThatTakesLong = async (params, log) =>
  new Promise((resolve, reject) => {
    setTimeout(() => {
      console.log(log);
      resolve(params);
    }, 5000);
  });

// Concurrency === 1 (default)
queue.process('func1', async ({ data: { params } }) => {
  console.log('Start func1');
  await doSomethingThatTakesLong(params, 'End func1');
  return true;
});

// Concurrency === 1 (default)
queue.process('func2', async ({ data: { params } }) => {
  console.log('Start func2');
  await doSomethingThatTakesLong(params, 'End func2');
  return true;
});

queue.add('func1', { params: 'hi one' });
queue.add('func2', { params: 'hi two' });
queue.add('func1', { params: 'hi one two' });
queue.add('func2', { params: 'hi two two' });