Question

I have a Rails 3.2.3 app with a very big cache in file store. Takes 30 minutes to clear the entire cache. I am trying to migrate the app to use the asset pipeline.

Found out that running rake assets:precompile actually clears the cache (see assets.rake for 3.2.3. I don’t think clearing the cache every time I need to deploy is a good idea, given the time it takes to clear the entire thing.

• Does the asset pipeline involve the cache?
• Why clear it, since everything is compiled to the public/assets folder? What if I am only caching fragments?
• Is there a way to use the pipeline without hitting the file store cache (and without
  clearing the cache every time I deploy)?

Thanks in advance!

Answer 1

After thinking about it for a while, I realized that is quite safe (and sometimes inevitable) to clear the cache every time images are updated.

If config.assets.digest = true, then when images are updated, the links to images in the cached pages/fragments need to be updated and busted in order for the new image to be used. If assets are cleaned up, failure to clean the cache will result in dead links, or until the browser loses its cache.

As for javascripts and stylesheets, the reason to clear the cache is to update the links to application.js and application.css files. But if we are careful to not cache the sources to JS and CSS files, clearing the cache is redundant.

Failure to do this results in using old JS and CSS files.