Rails

Start by adding the dalli gem to your Gemfile. Dalli is a Ruby memcache client.

gem 'dalli'

Then run bundle install:

$ bundle install

Once this gem is installed you’ll want to configure the Rails cache_store appropriately. Modify your config/environments/production.rb with the following:

config.cache_store = :mem_cache_store,
                    (ENV["MEMCACHIER_SERVERS"] || "").split(","),
                    {:username => ENV["MEMCACHIER_USERNAME"],
                     :password => ENV["MEMCACHIER_PASSWORD"],
                     :failover => true,
                     :socket_timeout => 1.5,
                     :socket_failure_delay => 0.2,
                     :down_retry_delay => 60
                    }

The values for MEMCACHIER_SERVERS, MEMCACHIER_USERNAME, and MEMCACHIER_PASSWORD are listed on your cache overview page. Make sure to add them to your environment.

In your development environment, Rails.cache defaults to a simple in-memory store and so it doesn’t require a running memcached.

From here you can use the following code examples to use the cache in your Rails app:

Rails.cache.write("foo", "bar")
puts Rails.cache.read("foo")

Rails 2

When adding the dalli gem to your Rails 2 Gemfile you will need to use dalli v1.0.5 as later versions of Dalli don’t support Rails 2.

gem 'dalli', '~>1.0.5'

Also modify config/environment.rb to contain:

config.gem 'dalli'

Else proceed just as newer Rails versions.