Book Image

Socket.IO Real-time Web Application Development

By : Rohit Rai
Book Image

Socket.IO Real-time Web Application Development

By: Rohit Rai

Overview of this book

<p>The expectations of users for interactivity withweb applications have changed over the past few years. No more does the user want to press the refresh button to check if new messages have arrived in their inbox; people expect to see updates in their applications in real-time. Mass multiplayer online games have given up the requirement of plugins and are built entirely in JavaScript. Socket.io enables you to build these highly interactive applications that work cross-browser.<br /><br />"Socket.io Real-time Web Application Development" is a guide to building, deploying, and scaling highly interactive real-time web applications using socket.io. This book will guide you through the building of a chat system using Node.js and socket.io, helping you get familiar with various features of the framework. Going further it will empower you to deploy and scale your applications in production.<br /><br />Introducing web application development with Node.js, this book walks you through developing of a full-fledged chat system built with socket.io and introducing all the concepts of socket.io and its usage in the process.<br /><br />It introduces you to the different approaches of bidirectional communication between the browser and the web server and will show you how socket.io abstracts all this for you to provide a single unified and uniform API for messaging and eventing to develop cross-browser applications. It explains how to authenticate your users, segregate the communication to channels, build chat rooms, and handle and scale sessions. It explains the mechanics behind socket.io and it also introduces you to what is involved in deploying the application to production and the intricacies involved in scaling it. <br /><br />This book will introduce you to all that is needed in browser-server communication to develop the next generation of interactive applications and games.</p>
Table of Contents (16 chapters)
Socket.IO Real-time Web Application Development
Credits
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Index

Scaling up the application


In the previous section we saw how we can cluster a Node.js app and how it remains restricted due to our application mechanisms. In its current state, the application uses an in-memory store to keep the session data. This store is local to the Node.js instance and so won't be accessible in any another clustered instance. Also, the data will be lost in a Node.js instance restart. So, what we need is a way to store the session in a persistent store. Also, we want to configure socket.io such that all its instances use a shared pub-sub and data store. The Connect framework has an extension mechanism so a new store can be plugged in, and there is one store that is persistent as well as excels at pub-sub. It is the Redis Session Store.

Redis (http://redis.io/) is a high performance, distributed, open source key-value store that can also be used as a queue. We will use Redis and corresponding Redis stores to provide a reliable, distributed, and shared store and pub-sub...