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
About the Authors
About the Reviewers
Clients for Your Favorite Language (Become a Redis Polyglot)

Keys without a namespace

It is good practice to use namespaces when defining your keys in Redis in order to avoid key name collisions and to organize your keys based on your application section or area.

In SQL databases, a namespace can be represented by the database name or the database tables.

Also, in a SQL database, it is reasonable to assume that a database called music-online has tables called album, song, and author.

Redis does not support namespacing. Usually, key name conventions are used to mimic namespaces. A common way of adding namespaces to Redis keys is by prepending a namespace (that is, namespace:key_name). Some Redis clients support addition of a prefix to all Redis keys.

Here are a few examples of key names with namespaces:

  • music-online:song:1

  • music-online:song:2

  • music-online:album:10001:metadata

  • music-online:album:10001:songs

  • music-online:author:123


    Multiple databases are not an excuse not to use proper key naming. Always use consistent namespaces.