How does Node.js handle concurrency and scalability?

image showing software scalability and concurrency

Node.js is a single-threaded, event-driven runtime environment that is designed to handle high levels of concurrency and scalability. In this tutorial, we will discuss how Node.js handles concurrency and scalability, and provide some examples of how to implement these concepts in your applications.

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Concurrency in Node.js

Node.js handles concurrency using an event-driven, non-blocking I/O model. This means that rather than waiting for I/O operations to complete before moving on to the next task, Node.js can execute multiple tasks simultaneously by delegating I/O operations to separate threads in the background.

For example, let’s say you have a Node.js application that needs to make multiple API requests to external services. Rather than waiting for each request to complete before moving on to the next one, Node.js can send each request in parallel and then process the responses as they arrive.

Here’s an example of how to implement concurrency in Node.js using the async module:

const async = require('async');

async.parallel([
  function(callback) {
    // Make API request 1
  },
  function(callback) {
    // Make API request 2
  },
  function(callback) {…