In this part of the tutorial we’ll write two small programs in nodejs; a producer that sends a single message, and a consumer that receives messages and prints them out. Concentrating on this very simple thing just to get started. It’s a “This is technical babaji” of messaging.

We’ll call our message publisher (sender) publisher.js and our message consumer (receiver) subscriber.js. The publisher will connect to RabbitMQ, send a single message, then exit.

RabbitMQ is a message broker: it accepts and forwards messages. You can think about it as a post office: when you put the mail that you want posting in a post box, you can be sure that Mr. or Ms. Mailperson will eventually deliver the mail to your recipient. In this analogy, RabbitMQ is a post box, a post office and a postman.

The major difference between RabbitMQ and the post office is that it doesn’t deal with paper, instead it accepts, stores and forwards binary blobs of data ‒ messages.

Producing means nothing more than sending. A program that sends messages is a producer

A queue is the name for a post box which lives inside RabbitMQ. Although messages flow through RabbitMQ and your applications, they can only be stored inside a queue. A queue is only bound by the host’s memory & disk limits, it’s essentially a large message buffer. Many producers can send messages that go to one queue, and many consumers can try to receive data from one queue. This is how we represent a queue

Consuming has a similar meaning to receiving. A consumer is a program that mostly waits to receive messages

Note: that the producer, consumer, and broker do not have to reside on the same host; indeed in most applications they don’t. An application can be both a producer and consumer, too.

#node #nodejs #javascript