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

Data type optimizations


In Redis, all data types can use different encodings to save memory or improve performance. For instance, a String that has only digits (for example, 12345) uses less memory than a string of letters (for example, abcde) because they use different encodings. Data types will use different encodings based on thresholds defined in the Redis server configuration.

Note

The redis-cli will be used in this section to inspect the encodings of each data type and to demonstrate how configurations can be tweaked to optimize for memory.

When Redis is downloaded, it comes with a file called redis.conf. This file is well documented and has all the Redis configuration directives, although some of them are commented out. Usually, the default values in this file are sufficient for most applications. The Redis configurations can also be specified via the command-line option or the CONFIG command; the most common approach is to use a configuration file.

For this section, we have decided to...