Rails 3 Action Sweeper on Heroku

application.rb

config.active_record.observers = :post_sweeper

application_controller.rb

class ApplicationController < ActionController::Base
  protect_from_forgery
  cache_sweeper :post_sweeper
end

Gemfile

gem 'memcachier'
gem 'dalli'

post_sweeper.rb

class PostSweeper < ActionController::Caching::Sweeper
  observe Post

  def after_save(post)
    expire_cache_for_post_index
  end

  private
  def expire_cache_for_post_index
    cache_key = "views/#{request.host_with_port}/posts"
    Rails.cache.delete(cache_key)
  end
end

posts_controller.rb

class PostsController < ApplicationController
  caches_action :index
  
  def index
    @posts = Post.published
  end

  def show
    @post = Post.find(params[:id])
  end
end

production.rb

config.cache_store = :dalli_store