Book Image

Mastering Node.js

By : Sandro Pasquali
Book Image

Mastering Node.js

By: Sandro Pasquali

Overview of this book

Node.js is a modern development stack focused on providing an easy way to build scalable network software. Backed by a growing number of large companies and a rapidly increasing developer base, Node is revolutionizing the way that software is being built today. Powered by Google's V8 engine and built out of C++ modules, this is a JavaScript environment for the enterprise.Mastering Node.js will take the reader deep into this exciting development environment. Beginning with a comprehensive breakdown of its innovative non-blocking evented design, Node's structure is explained in detail, laying out how its blazingly fast I/O performance simplifies the creation of fast servers, scalable architectures, and responsive web applications.Mastering Node.js takes you through a concise yet thorough tour of Node's innovative evented non-blocking design, showing you how to build professional applications with the help of detailed examples.Learn how to integrate your applications with Facebook and Twitter, Amazon and Google, creating social apps and programs reaching thousands of collaborators on the cloud. See how the Express and Path frameworks make the creation of professional web applications painless. Set up one, two, or an entire server cluster with just a few lines of code, ready to scale as soon as you're ready to launch. Move data seamlessly between databases and file systems, between clients, and across network protocols, using a beautifully designed, consistent, and predictable set of tools.Mastering Node.js contains all of the examples and explanations you'll need to build applications in a short amount of time and at a low cost, running on a scale and speed that would have been nearly impossible just a few years ago.
Table of Contents (20 chapters)
Mastering Node.js
About the Author
About the Reviewers


The Internet is no longer a collection of static websites to be passively consumed. The browser user has come to expect a much richer, interactive experience. Over the last decade or so, network applications have come to resemble desktop applications. Also, recognition of the social characteristics of information has inspired the development of new kinds of interfaces and visualizations modeling dynamic network states, where the user is viewing change over real time rather than fading snapshots trapped in the past.

Even though our expectations for software have changed, the tools available to us as software developers developers have not changed much. Computers are faster, and multicore chip architectures are common. Data storage is cheaper, as is bandwidth. Yet we continue to develop with tools designed before billion-user websites and push-button management of cloud-based clusters of virtual machines.

The development of network applications remains an overly expensive and slow process because of this. Developers use different languages, programming styles, complicating code maintenance, debugging, and more. Too regularly, scaling issues arrive too early, overwhelming the ability of what is often a small and inexperienced team. Popular modern software features, such as real-time data, multiplayer games, and collaborative editing spaces, demand systems capable of carrying thousands of simultaneous connections without bending. Yet we remain restricted to frameworks designed to assist us in building CRUD applications binding a single relational database on a single server to a single user running a multipage website in a browser on a desktop computer.

Node helps developers build more resilient network applications at scale. Built on C++ and bundled with Google's V8 engine, Node is fast, and it understands JavaScript. Node has brought together the most popular programming language in the world and the fastest JavaScript compiler around, and has given that team easy access to an operating system through C++ bindings. Node represents a change in how network software is designed and built.

What this book covers

Chapter 1, Understanding the Node Environment, gives a brief description of the particular problems Node attempts to solve, with a focus on how its single-threaded event-loop is designed, implemented, and used. We will also learn about how Google's V8 engine can be configured and managed, as well as best practices when building Node programs.

Chapter 2, Understanding Asynchronous Event-Driven Programming, digs deep into the fundamental characteristic of Node's design: event-driven, asynchronous programming. By the end of this chapter you will understand how events, callbacks, and timers are used in Node, as well as how the event loop works to enable high-speed I/O across filesystems, networks, and processes.

Chapter 3, Streaming Data Across Nodes and Clients, describes how streams of I/O data are knitted through most network software, emitted by file servers or broadcast in response to an HTTP GET request. Here we learn how Node facilitates the design, implementation, and composition of network software, using examples of HTTP servers, readable and writable file streams, and other I/O focused Node modules and patterns.

Chapter 4, Using Node to Access the Filesystem, lays out what you need to know when accessing the filesystem with Node, along with techniques for handling file uploads and other networked file operations.

Chapter 5, Managing Many Simultaneous Client Connections, shows you how Node helps in solving problems accompanying the high volume, high concurrency environments that contemporary, collaborative web applications demand. Through examples, learn how to efficiently track user state, route HTTP requests, handle sessions, and authenticate requests using the Redis database and Express web application framework.

Chapter 6, Creating Real-Time Applications, explores AJAX, Server-Sent-Events, and the WebSocket protocol, discussing their pros and cons, and how to implement each using Node. We finish the chapter by building a collaborative document editing application.

Chapter 7, Utilizing Multiple Processes, teaches how to distribute clusters of Node processes across multi-core processors, and other techniques for scaling Node applications. An investigation of the differences between programming in single and multithreaded environments leads to a discussion of how to spawn, fork, and communicate with child processes in Node, and we build an analytics tool that records, and displays, the mouse actions of multiple, simultaneous clients connected through a cluster of web sockets.

Chapter 8, Scaling Your Application, outlines some techniques for detecting when to scale, deciding how to scale, and scaling Node applications across multiple servers and cloud services, with examples including: how to use RabbitMQ as a message queue, using NGINX to proxy Node servers, and using Amazon Web Services in your application.

Chapter 9, Testing Your Application, explains how to implement unit, functional, and integration tests with Node. We will explore several testing libraries, including native Node assertion, sandboxing, and debugging modules. Examples using Grunt, Mocha, PhantomJS, and other build and testing tools accompany the discussion.

Appendix A, Organizing Your Work, gives tips on using the npm package management system. Learn how create packages, publish packages, and manage packages.

Appendix B, Introducing the Path Framework, demonstrates how to use this powerful full-stack application framework to build your next web application using only JavaScript, thanks to Node and its ability to handle thousands of simultaneously connected clients.

Appendix C, Creating Your Own C++ Add-ons, provides a brief introduction on how to build your own C++ add-ons, and how to use them from within Node.

What you need for this book

You will need to have some familiarity with JavaScript, and have a copy of Node installed on your development machine or server, Version 0.10.21 or higher. You should know how to install programs on this machine, as you will need to install Redis, along with other libraries, like PhantomJS. Having Git installed, and learning how to clone GitHub repositories, will greatly improve your experience.

You should install RabbitMQ so that you can follow with the examples using message queues. The sections on using NGINX to proxy Node servers will of course require that you can install and use that web server. To build C++ add-ons you will need to install the appropriate compiler on your system.

The examples in this book are built and tested within UNIX-based environments (including Mac OS X), but you should be able to run all Node examples on Windows-based operating systems as well. You can obtain installers for your system, and binaries, from

Who this book is for

This book is for developers who want to build high-capacity network applications, such as social networks, collaborative document editing environments, real time data-driven web interfaces, networked games, and other I/O-heavy software. If you're a client-side JavaScript developer, reading this book will teach you how to become a server-side programmer using a language you already know. If you're a C++ hacker, Node is an open-source project built using that language, offering you an excellent opportunity to make a real impact within a large and growing community, even gaining fame, by helping to develop this exciting new technology.

This book is also for technical managers and others seeking an explanation of the capabilities and design philosophy of Node. The book is filled with examples of how Node solves the problems modern software companies are facing in terms of high-concurrency, real-time applications pushing enormous volumes of data through growing networks. Node has already been embraced by the enterprise, and you should consider it for your next project.


In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "To import modules into your Node program use the require directive."

A block of code is set as follows:

var EventEmitter = require('events').EventEmitter;
var Counter = function(init) {
  this.increment = function() {
      this.emit('incremented', init);

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

var size = process.argv[2];
var totl = process.argv[3] || 100;
var buff = [];
for(var i=0; i < totl; i++) {
  buff.push(new Buffer(size));
  process.stdout.write(process.memoryUsage().heapTotal + "\n");

Any command-line input or output is written as follows:

> node process.js 1000000 100 > out.file

New terms and important words are shown in bold.


Warnings or important notes appear in a box like this.


Tips and tricks appear like this.

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