How to setup Memcache for performance optimization in Ruby on Rails


Ruby on Rails is renowned for its rapid development capabilities, but as your application grows, performance issues may arise. Caching is a powerful solution to enhance performance, and in this blog post, we’ll delve into how to harness the potential of Memcached, an in-memory caching system, to optimize your Rails application.

Step 1: Installing Memcached

To get started, you’ll need to install Memcached on your system. The installation process varies depending on your operating system. Here are the steps for macOS:

For macOS (using Homebrew and zsh):

  1. Open your terminal.
  2. Install Memcached using Homebrew:
brew install memcached

After installation, start the Memcached server:


You can specify a port and memory limit if needed.

Step 2: Adding the dalli Gem

Now that Memcached is up and running, it’s time to integrate it with your Rails application. We’ll use the dalli gem for this purpose. Here’s how to do it:

  1. Open your Rails application’s Gemfile and add the dalli gem:
   gem 'dalli'
  1. Run the following command to install the gem:
   bundle install

Step 3: Configuring Memcached

Next, you’ll need to configure your Rails application to use Memcached. This involves setting the cache store in your environment configuration.

  1. Open the config/environments/development.rb file (or the desired environment file, e.g., production.rb).
  2. Add the Memcached configuration to specify the cache store:
   config.cache_store = :dalli_store

You can also set Memcached server settings, such as the server hostname and port, in this configuration.

Step 4: Basic Usage

With Memcached integrated, you can start using it to cache data in your Rails application. Here are two common use cases:

Caching Query Results:

You can cache the results of a database query in your controller or model. For example:

@data = Rails.cache.fetch('data_key', expires_in: 1.hour) do

Caching Rendered Views:

To improve page load times, you can cache rendered views or fragments in your views:

<% cache 'my_cached_view' do %>
  <!-- Your view content -->
<% end %>

Step 5: Monitoring and Debugging

As you start caching data with Memcached, you may want to monitor its performance and debug any issues. You can use tools like memcached-tool to view statistics and diagnose potential problems.

memcached-tool localhost:11211 stats


By following these steps, you’ve successfully installed Memcached and integrated it into your Ruby on Rails application. You’re now equipped to cache data and significantly improve your application’s performance.

As you continue to work with Memcached, remember to fine-tune your caching strategy and monitor its performance to ensure optimal results.

Related Post