Rails caching

Overview of rails caching techniques

Transcript

1. Rails caching - Manthan Damania
2. Caching Strategies HTTP Caching: Uses HTTP headers. Page caching: Caches the whole response of the page to be served by web servers (nginx/apache) Action Caching: Same as page caching except it can be private. Fragment caching: Store parts of html page in cache. SQL caching: Caches query result during a single request. Enabled in rails by default. Low level caching: Can store any type of object in cache. Static Assets Caching: Used for JS, CSS, Images etc
3. HTTP caching Done at both client and server side Works at protocol layer Response is stored in user’s browser depending upon headers from the server Strong and weak Etags Max-age, Expires, Public/Private
7. Page caching Done at server side Caches the whole page which can be served via front end server (nginx/apache) Skips whole application server once cache is stored T o expire caches use sweepers
8. Action Caching Page caching can not be used for pages which requires authentication (or any before filters) Action caching same as page caching but allows before filters to run
9. Fragment Caching Cache section of pages Uses object’s updated_at column to determine get the latest cache
10. Static Assets Caching Done for JS and CSS files Etags are used in file names in rails. So web server can send appropriate responses to the browser /assets/ application-9ea8d161dc03c8b77398d9e6e8ec452f.js Max age is set Optionally don’t do this yourself. Leave it to CDNs
11. Low level caching Used to compute complex result/queries Rails.cache.fetch(‘complex_result’) { User.find(params[:id]) }
12. Cache stores In memory (in this presentation) Filestore Memcached Redis Varnish
13. There are only two hard things in Computer Science: cache invalidation, naming things, and off-by-one errors.
14. References http://hawkins.io/2012/07/advanced_caching_part_1-caching_strategies/ http://guides.rubyonrails.org/caching_with_rails.html http://2ndscale.com/rtomayko/2008/things-caches-do
15. Questions?
16. Thank you