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Speeding up with Rails Caching

Caching, essentially, involves storing content generated during a request-response cycle to reuse it when similar requests occur. This significantly impacts web applications, especially those developed using the Ruby on Rails framework, which is the focus of this article.

What is Rails Caching?

Rails Caching is a feature inherent to the Ruby on Rails framework that delivers an impactful performance boost to web applications. It allows websites, even those on a single server, to handle heavy loads and maintain functionality even with thousands of concurrent users.

Why Use Rails Caching?

The utility of Rails Caching comes from its capability to enhance application performance. It dramatically reduces the time taken to respond to user requests by preventing unnecessary database queries, thus making your application faster and more efficient.

Caching Types in Rails

There are three primary types of caching techniques in Rails:

  1. Page
  2. Action
  3. Fragment Caching.

By default, caching is enabled only in a production environment, but you can tinker with caching locally with certain commands/settings.

Configuring Rails Caching

For caching to operate effectively, it requires proper configuration, usually done in the config/environments/development.rb file. You can activate caching either by running the rails dev:cache command or by setting config.action_controller.perform_caching to true.

Diving into Different Caching Strategies

Page Caching

Page Caching is a simple method that stores the entire HTML of a page in the cache. This allows the server to deliver the HTML file directly, bypassing the need to hit the Rails stack, thus rendering the response quickly.

Action Caching

Action Caching, akin to Page Caching, delivers the cache after the incoming web request reaches the Rails stack. This proves advantageous when filters need to execute before the cache is served, typically for authentication or other restrictions.

Fragment Caching

Fragment Caching permits wrapping bits of view logic in a cache block, which is ideal when only certain sections of a page frequently change. It stores a cache version alongside the fragment, and when the associated record updates, the cache version changes, thus invalidating the cached content.

Russian Doll Caching

Russian Doll Caching is a concept that optimizes fragment caching. The idea revolves around nestling cache fragments within each other for smarter and more efficient busting of the cache.

Cache Stores in Rails


The Memcached cache store is an effective caching system, offering performance benefits for high-traffic websites. It automatically deletes old cache files, an essential feature for easy maintenance of cache-based systems.


The MemoryStore cache holds entries in memory within the same Ruby process. It’s easy to use, but one should exercise caution since it’s not designed for handling large amounts of data or long-term storage.


The FileStore uses the file system to keep entries cached. This cache store is most suitable for smaller to medium-traffic sites operated from one or two hosts.


RedisCacheStore leverages the power of Redis for automatic eviction as it reaches its memory limit. Redis is incredibly efficient and thus an excellent choice for many applications.


Rails caching offers remarkable pre-emptive solutions to issues related to web application performance, making it a crucial tool in the web developer’s kit.

Getting to grips with Rails caching strategies such as Page, Action, Fragment, and Russian Doll caching, and understanding how to manipulate cache stores are all instrumental in boosting the efficacy of your Rails-based web application. Caching, when used judiciously, can greatly enhance the scalability of your application.

Please continue your Rails tutorial series by reading our previous article on Active Record Associations in Rails.


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