Book Image

Mastering Redis

By : Vidyasagar N V, Jeremy Nelson
Book Image

Mastering Redis

By: Vidyasagar N V, Jeremy Nelson

Overview of this book

Redis is the most popular, open-source, key value data structure server that provides a wide range of capabilities on which multiple platforms can be be built. Its fast and flexible data structures give your existing applications an edge in the development environment. This book is a practical guide which aims to help you deep dive into the world of Redis data structure to exploit its excellent features. We start our journey by understanding the need of Redis in brief, followed by an explanation of Advanced key management. Next, you will learn about design patterns, best practices for using Redis in DevOps environment and Docker containerization paradigm in detail. After this, you will understand the concept of scaling with Redis cluster and Redis Sentinel , followed by a through explanation of incorporating Redis with NoSQL technologies such as Elasticsearch and MongoDB. At the end of this section, you will be able to develop competent applications using these technologies. You will then explore the message queuing and task management features of Redis and will be able to implement them in your applications. Finally, you will learn how Redis can be used to build real-time data analytic dashboards, for different disparate data streams.
Table of Contents (18 chapters)
Mastering Redis
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

LRU key evictions


To demonstrate the various options for key evictions in Redis, we'll start with a simple example by setting a small memory Redis instance that the maxmemory directive sets to 1 megabyte. The maxmemory directive allows you set a hard upper bound on the amount of memory that is available to a running Redis instance. Echoing the warnings in the default redis.conf file, setting the maxmemory has ramifications that we'll now see. To start with, we'll just create a very simple Redis key schema, that of generating and storing a unique id for a web application. After connecting to a Redis instance through Redis-cli, we'll run the following commands to clear out our datastore and then set the maxmemory directive to 1 megabyte:

127.0.0.1:6379> FLUSHALL
OK
127.0.0.1:6379>CONFIG SET maxmemory1mb
OK

Next, we'll implement a function that takes a Redis instance, increments a global uuid, and then generates a random UUID from the standard uuid Python module. The add_id function...