Capistrano task to flush memcached cache.

cache.rake

namespace :cache do
  desc 'Clear memcache'
  task :clear => :environment do
    Rails.cache.clear
  end
end

deploy.rb

#add somewhere in deploy.rb

namespace :memcached do
  desc "Flush memcached"
  task :clear do
    on roles(:app) do
      within release_path do
        execute :bundle, :exec, "rake cache:clear RAILS_ENV=#{fetch(:stage)}"
      end
    end
  end
end