Book Image

Node.js Web Development - Fifth Edition

By : David Herron
Book Image

Node.js Web Development - Fifth Edition

By: David Herron

Overview of this book

Node.js is the leading choice of server-side web development platform, enabling developers to use the same tools and paradigms for both server-side and client-side software. This updated fifth edition of Node.js Web Development focuses on the new features of Node.js 14, Express 4.x, and ECMAScript, taking you through modern concepts, techniques, and best practices for using Node.js. The book starts by helping you get to grips with the concepts of building server-side web apps with Node.js. You’ll learn how to develop a complete Node.js web app, with a backend database tier to help you explore several databases. You'll deploy the app to real web servers, including a cloud hosting platform built on AWS EC2 using Terraform and Docker Swarm, while integrating other tools such as Redis and NGINX. As you advance, you'll learn about unit and functional testing, along with deploying test infrastructure using Docker. Finally, you'll discover how to harden Node.js app security, use Let's Encrypt to provision the HTTPS service, and implement several forms of app security with the help of expert practices. With each chapter, the book will help you put your knowledge into practice throughout the entire life cycle of developing a web app. By the end of this Node.js book, you’ll have gained practical Node.js web development knowledge and be able to build and deploy your own apps on a public web hosting solution.
Table of Contents (19 chapters)
1
Section 1: Introduction to Node.js
6
Section 2: Developing the Express Application
12
Section 3: Deployment

Scaling up – running multiple Notes instances

Now that we've got ourselves a running application, you'll have played around a bit and created, read, updated, and deleted many notes.

Suppose for a moment that this isn't a toy application, but one that is interesting enough to draw millions of users a day. Serving a high load typically means adding servers, load balancers, and many other things. A core part of this is to have multiple instances of the application running at the same time to spread the load.

Let's see what happens when you run multiple instances of the Notes application at the same time.

The first thing is to make sure the instances are on different ports. In app.mjs, you'll see that setting the PORT environment variable controls the port being used. If the PORT variable is not set, it defaults to http://localhost:3000, or what we've been using all along.

Let's open up package.json and add the following lines to the scripts section...