Node.js Bee-queue tutorial – NPM package for Queues

Installation

To start using the npm package bee-queue in your Node.js project, you first need to install it via npm:

npm install bee-queue

Creating Jobs

To create a job in bee-queue, you set up a queue, create a job with data, and save it. Here’s a simple example:

const Queue = require('bee-queue');
const myQueue = new Queue('example');

function createJob(data) {
  const job = myQueue.createJob(data);
  job.save();
  job.on('succeeded', (result) => {
    console.log(`Job ${job.id} succeeded with result: ${result}`);
  });
}

createJob({x: 2, y: 3});  // Function call with data

Output:

`Job 1 succeeded with result: 5`

Repeated Jobs

To set up repeated jobs, you need to define the job and instruct the queue on how often it should repeat:

// This functionality is not a part of bee-queue by default. You will need to implement a scheduler.
// The following is a conceptual example.
function createRepeatedJob(data, interval) {
  setInterval(() => {
    const job = myQueue.createJob(data);
    job.save();
  }, interval);
}

createRepeatedJob({ task: 'heartbeat' }, 60000);  // Call function to create a job every minute

Delayed Jobs

To create a delayed job, you must specify the delay before your job starts processing:

function createDelayedJob(data, delay) {
  const job = myQueue.createJob(data).delayUntil(Date.now() + delay);
  job.save();
}

createDelayedJob({ email: '[email protected]' }, 5000);  // Call function to delay job by 5 seconds

Setting Job Priority

You can set a priority for each job, which determines the order in which jobs are processed:

function createJobWithPriority(data, priority) {
  const job = myQueue.createJob(data).priority(priority);
  job.save();
}

createJobWithPriority({ email: '[email protected]' }, 'high');  // Call function with high priority

Managing Concurrency

bee-queue allows you to control the number of concurrent jobs being processed:

const queueWithConcurrency = new Queue('concurrent', { 
  settings: { 
    activateDelayedJobs: true,
    concurrency: 5
  } 
});

queueWithConcurrency.process(function (job, done) {
  console.log(`Processing job ${job.id}`);
  done();
});

Global Events

Global events can be listened to for various queue activities. Here’s how you do it:

myQueue.on('ready', () => {
  console.log('Queue is ready!');
});

myQueue.on('error', (err) => {
  console.log('A queue error happened:', err);
});

myQueue.on('succeeded', (job, result) => {
  console.log(`Job ${job.id} succeeded with result: ${result}`);
});

Pausing and Resuming Queues

bee-queue allows you to pause and resume the processing of jobs:

async function pauseQueue() {
  await myQueue.pause(false, true);
}

async function resumeQueue() {
  await myQueue.resume();
}

pauseQueue(); // Pauses the queue without waiting for ongoing jobs
resumeQueue(); // Resumes job processing in the queue

Job Retries

You can set a number of retries for a job in case it fails:

function createJobWithRetries(data, retries) {
  const job = myQueue.createJob(data).retries(retries);
  job.save();
}

createJobWithRetries({ task: 'important' }, 3);  // Call function that retries job up to 3 times

Troubleshooting Tips

If you encounter issues while using bee-queue, check for these common problems:

• Ensure Redis server is running and accessible.
• Check for the correct version of Node.js and Redis compatibility.
• Validate that there are no errors in your job processors.
• Check the documentation or issues on the bee-queue GitHub repository for similar problems and solutions.

Summary

In this tutorial, we have discussed how to use bee-queue for queue management in Node.js applications, covering features such as creating, delaying, and prioritizing jobs; setting up concurrency and global events; rate limiting; as well as pausing, resuming, and retrying jobs. Bee-queue is a powerful yet simple tool that can help you efficiently manage background tasks in your Node.js projects.

References

• Bee-Queue GitHub Repository
• Bee-Queue on npm