Book Image

Node.js Web Development - Third Edition

By : David Herron
Book Image

Node.js Web Development - Third Edition

By: David Herron

Overview of this book

Node.js is a server-side JavaScript platform using an event driven, non-blocking I/O model allowing users to build fast and scalable data-intensive applications running in real time. Node.js Web Development shows JavaScript is not just for browser-side applications. It can be used for server-side web application development, real-time applications, microservices, and much more. This book gives you an excellent starting point, bringing you straight to the heart of developing web applications with Node.js. You will progress from a rudimentary knowledge of JavaScript and server-side development to being able to create and maintain your own Node.js application. With this book you'll learn how to use the HTTP Server and Client objects, data storage with both SQL and MongoDB databases, real-time applications with Socket.IO, mobile-first theming with Bootstrap, microservice deployment with Docker, authenticating against third-party services using OAuth, and much more.
Table of Contents (18 chapters)
Node.js Web Development Third Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

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 this isn't a toy application, but one that is interesting enough to draw a million users a day. Serving a high load typically means adding servers, load balancers, and many other things. A core part 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 bin/www, you'll find these lines, which control the port being used:

var port = normalizePort(process.env.PORT || '3000');
app.set('port', port);

Meaning it's just a matter of setting the PORT environment variable to the desired value. If the PORT variable is not set, it defaults to http://localhost:3000, or what we've been using all along...