Book Image

Redis Essentials

Book Image

Redis Essentials

Overview of this book

Redis is the most popular in-memory key-value data store. It's very lightweight and its data types give it an edge over the other competitors. If you need an in-memory database or a high-performance cache system that is simple to use and highly scalable, Redis is what you need. Redis Essentials is a fast-paced guide that teaches the fundamentals on data types, explains how to manage data through commands, and shares experiences from big players in the industry. We start off by explaining the basics of Redis followed by the various data types such as Strings, hashes, lists, and more. Next, Common pitfalls for various scenarios are described, followed by solutions to ensure you do not fall into common traps. After this, major differences between client implementations in PHP, Python, and Ruby are presented. Next, you will learn how to extend Redis with Lua, get to know security techniques such as basic authorization, firewall rules, and SSL encryption, and discover how to use Twemproxy, Redis Sentinel, and Redis Cluster to scale infrastructures horizontally. At the end of this book, you will be able to utilize all the essential features of Redis to optimize your project's performance.
Table of Contents (17 chapters)
Redis Essentials
Credits
About the Authors
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
5
Clients for Your Favorite Language (Become a Redis Polyglot)
Index

Hello World with Node.js and Redis


This section shows the basics of creating a JavaScript program using Redis. It is important to understand this foundation since the upcoming examples use the same principles.

Note

In this book, all filenames, function names, and variable names are italicized. Some sentences follow this convention:

  • Create a file called my-filename.js.

  • Execute the function myFunctionName.

  • Create a variable called myVariableName.

Create a file called hello.js with the following code:

var redis = require("redis"); // 1
var client = redis.createClient(); // 2
client.set("my_key", "Hello World using Node.js and Redis"); // 3
client.get("my_key", redis.print); // 4
client.quit(); // 5

Note

Please note that all the code snippets in this book will have inline comments with numbers. After the code is presented, it will be explained by referencing those numbers.

  1. Require the redis library in Node.js. This is equivalent to import in Go, Python, or Java.

  2. Create the Redis client object.

  3. Execute the Redis command SET to save a String in a key called my_key.

  4. Execute the Redis command GET to get the value stored in my_key, and then output it.

  5. Close the connection with the Redis server.

    Note

    Lines 1, 2, and 5 of this example will be used in the majority of the examples that use Node.js.

Run hello.js with the node command (node is the Node.js interpreter):

$ node hello.js
Reply: Hello World using Node.js and Redis