Railsでmemcacheはこんなかんじ config/initializers/session_store.rb に case ENV['RAILS_ENV'] when 'development', 'test' ActionController::Base.session = { :key => '___session', :secret => '***' } when 'production' ActionController::Base.session = { :memcache_server => ['127.0.0.1:11211', '127.0.0.1:11212'], :expire_after => 86400, :namespace => "__-#{ENV['RAILS_ENV']}", :key => '___session', :secret => '***' } ActionController::Base.session_store = :mem_cache_store end