Introduction to busmq

busmq is a messaging library for Node.js applications that supports various messaging patterns including queues, topics, and more. It’s designed for high performance, fault tolerance, and easy integration with multiple backends like Redis and MongoDB.

Setting Up busmq

  
    const Bus = require('busmq');
    const bus = Bus.create({ redis: ['redis://localhost:6379'] });
    bus.connect();
  

Working with Queues

Queues are one of the fundamental features of busmq. Let’s see how to use them.

Creating a Queue

  
    const queue = bus.queue('myQueue');
    queue.attach();
  

Adding Messages to a Queue

  
     queue.push('message1');
     queue.push('message2');
  

Processing Messages from a Queue

  
    queue.on('message', (message) => {
      console.log('Received:', message);
    });
    queue.consume();
  

Working with Topics

Topics enable publishing messages to multiple subscribers.

Creating a Topic

  
    const topic = bus.topic('myTopic');
    topic.attach();
  

Publishing Messages to a Topic

  
    topic.publish('Hello subscribers!');
  

Subscribing to a Topic

  
    topic.on('message', (message) => {
      console.log('Received:', message);
    });
    topic.subscribe();
  

Monitoring System Health

busmq provides built-in support for monitoring the health of your message buses.

Health Check Example

  
    bus.on('online', () => {
      console.log('Bus is online');
    });

    bus.on('offline', () => {
      console.log('Bus is offline');
    });
  

Example Application

Let’s create a simple application combining the features above.

Producer

  
    const producerQueue = bus.queue('appQueue');
    producerQueue.attach();

    setInterval(() => {
      const message = `Message at ${new Date().toISOString()}`;
      producerQueue.push(message);
      console.log('Produced:', message);
    }, 1000);
  

Consumer

  
    const consumerQueue = bus.queue('appQueue');
    consumerQueue.attach();

    consumerQueue.on('message', (message) => {
      console.log('Consumed:', message);
    });

    consumerQueue.consume();
  

Now run both producer and consumer scripts to see the message flow.