Question

I am taking over development on a rails 3.2 application and am looking for the best way to improve page loading time. The site itself is more of a large dynamic website than an actual web application (the site is http://korduroy.tv/, a surf lifestyle community site), and while there is a couple of small pieces that differ from user to user, most of the site is the same experience for everyone.

Page loading time is fairly slow, and from looking at the server logs, it seems to be because each page is loading so much dynamic content (for example, most pages are loading resources from 10+ models). While I hope to go through and refactor what I can, I am looking for some basic performance wins. Knowing that most of the site is the same for every user, is their a way to aggressively cache the content on the server or even serve static content that has been generated through some kind of background job?

My initial thought was to create a job that uses a static site generator, maybe something like Jekyl, and basically creates a static copy of the site, which could then be served on a cdn. My gut is telling me this is probably not the way to do it, plus there are some pages (such as the user profile page), that need to be served dynamically.

Any recommendations would be great. Disclaimer, I come from front end land and have very little knowledge of best practices when it comes to server side optimizations. Thanks!

Answer 1

From what you write, I believe your biggest gain will be in implementing a fragment cache using a memcache store. See http://guides.rubyonrails.org/caching_with_rails.html as the definitive guide on rails caching.

You might be able to get away with a page cache or action caches for some of the content that doesn’t depend on the user (like the homepage), but unless you’re serving up millions of requests a day, I’m not sure this is necessary.

I notice that while the javascript and css seems to be compiled according to the rails asset pipeline, the images are missing the sha1 hashes that allow aggressive browser caching of the resources (since you don’t have to worry about the contents changing, as they get new hashes when you change the images). The key here is enabling the asset pipeline, making sure you compile your assets as part of deployment (rake assets:precompile) and using the image_tag and asset_path helpers (or image-url sass helper). Also make sure that nginx is responding with code 304 (not modified) to your browser when you’re refreshing a page. This won’t affect the load on the rails server (unless you have both nginx and rails running on the same server), but will reduce the average page load time.

You can look into more advanced techniques like caching your sql queries, or optimizing these, but this can lead to increased complexity making it harder to maintain your codebase. Try the view caching first, and see if that gets the load time to an acceptable level.