Performance

Redis

Redis is a high performance, in-memory key-value data store which can be persisted to disk.

Install

MacOS

Presuming you have Homebrew installed, you can install the Redis recipe:

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brew install redisredis-server /usr/local/etc/redis.conf

Ubuntu

There are a few options to install Redis on Ubuntu. The first and easiest is to use apt:

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sudo apt-get install redis-server

This will set up redis-server to startup with the OS, but it may be a slightly dated version.

To get the latest stable version you can download from http://redis.io/download and install using their directions.

Windows

There is no official Redis server version for Windows. There is a third-party port of the original service which can be used for development but may not offer 100% compatibility:

https://github.com/dmajkic/redis/

redis-rails

Redis-Rails hooks into Rails’s caching layer in order to provide Redis as the backend caching mechanism.

Install

Install redis-rails by adding gem 'redis-rails' to the Gemfile and running bundle.

Typical Configuration

To run experiments in these tutorials, use the following configuration in config/environments/development.rb:

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AppName::Application.configure do
  ...
  config.cache_store = :redis_store, "redis://localhost:6379/1/ns"
  ...
end

Caching in Development?

If you want to turn on caching in development (while testing / learning about Redis), in the same config/environments/development.rb file:

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AppName::Application.configure do
  ...
  config.cache_store = :redis_store, "redis://localhost:6379/1/ns"
  config.action_controller.perform_caching = true
  ...
end

Configuration Options

The options to configure how redis-rails connects to Redis are as follows with the default values:

• host: IP address or DNS of the host to connect to [default: localhost]
• port: port Redis is listening on [default: 6379]
• db: which Redis database to select after connecting [default: 0]
• namespace: string to prefix redis keys [default: nil]
• password: authentication password for Redis [default: nil]

A hash with the above keys or a string may be specified to connect. The format of the string looks like:

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redis://:secret@localhost:6379/1/namespace

:secret@ and /1/namespace are optional fragments of this string, but note that if you want to specify a namespace the DB number must also be provided.