Redis cache system. Some references.

links.txt

# Redis server setup
http://blog.sensible.io/2013/08/20/setting-up-redis-for-production-environment.html
# Redis for Ruby
https://github.com/redis/redis-rb
# Redis and rails
http://jimneath.org/2011/03/24/using-redis-with-ruby-on-rails.html
# Redis cache
http://www.ryanalynporter.com/2012/06/12/simple-redis-caching-in-ruby/