Asset Redux - Front end performance on Rails

Web application speed is paramount. Our users want our application and they want it now! We can optimise application code, database queries and so on, but that's all wasted if the page takes ages to appear. A fast back end and a slow front end can end up leaving a bad taste in the mouth.

Using Rails, we'll look at the best ways to speed up the delivery of your application. Going beyond just minifying our assets, we'll look at techniques to get our site in the user's browser quicker, improving both real and perceived speed. We'll also discover the best tools to use to check out speed and get a better idea of the user's opinion of the site.Once finished, our sites will load in a flash!

Links from the slides:

HTTP Archive trends: http://httparchive.org/trends.php

Tools

WebPageTest
Google PageSpeed Insights
Yahoo! YSlow

High Performance Browser Networking by Ilya Grigorik
Perception of speed
DOM, CSSOM and JavaScript

Rails guides on gzip compression

Serve gzipped assets on Heroku:
heroku_rails_deflate
rack-zippy

CSS and the critical path:
Patrick Hamann on CSS and the critical path
The Guardian team load CSS from localStorage
Critical path CSS generator

Lossless compression of images:
Asset pipeline preprocessor
paperclip-optimizer
carrierwave-imageoptimizer

Progressive JPEGs:
Book of Speed
image_optim

Inlining:
rails-sass-images

Transcript

1. ASSET REDUX London Web — August 2014
2. Phil Nash @philnash philnash@twilio.com
3. PERFORMANCE & RAILS
4. FRONT END PERFORMANCE
5. Why front end performance? •  Sites are getting bigger •  More people are going mobile •  I'm a busy person
6. Top 1000 sites Month/Year Average page size Average number of requests June/2011 690kB 85 June/2014 1492kB 108 Source: http archive
7. Why Rails? •  It's what I know
8. Why Rails? But seriously...
9. WHY AM I TALKING ABOUT THIS?
12. PERFORMANT BY DEFAULT
13. TOOLS
14. Tools •   WebPageTest •   Google PageSpeed Insights •   YSlow •   Real User Monitoring
15. The problems •  Bandwidth •  Latency •  User attention
16. Delay User perception 0-100ms Instant 100-300ms Small perceptible delay 300-1000ms Machine is working 1000+ms Likely mental context switch 10000+ms Task is abandoned Source: High performance browser networking
17. FAST FRONT ENDS
18. WARNING!
19. TEXT ASSETS
20. CONCATENATE AND MINIFY Thanks asset pipeline!
21. CHOOSE WHAT TO CONCATENATE
22. GZIP Thanks asset pipeline!
23. I <3 ASSET PIPELINE
24. nginx l o c a t i o n ~ ^ / ( a s s e t s ) / { r o o t / p a t h / t o / p u b l i c ; g z i p _ s t a t i c o n ; # t o s e r v e p r e - g z i p p e d v e r s i o n e x p i r e s m a x ; a d d _ h e a d e r C a c h e - C o n t r o l p u b l i c ; } Source: RailsGuides 0 1 . 0 2 . 0 3 . 0 4 . 0 5 . 0 6 .
25. Heroku •  heroku_rails_deflate •  rack-zippy
26. CACHE HEADERS
27. nginx l o c a t i o n ~ ^ / ( a s s e t s ) / { r o o t / p a t h / t o / p u b l i c ; g z i p _ s t a t i c o n ; e x p i r e s m a x ; a d d _ h e a d e r C a c h e - C o n t r o l p u b l i c ; } 0 1 . 0 2 . 0 3 . 0 4 . 0 5 . 0 6 .
28. Heroku M y A p p : : A p p l i c a t i o n . c o n f i g u r e d o c o n f i g . s e r v e _ s t a t i c _ a s s e t s = t r u e c o n f i g . s t a t i c _ c a c h e _ c o n t r o l = " p u b l i c , m a x - a g e = 3 1 5 3 6 0 0 0 " e n d 0 1 . 0 2 . 0 3 . 0 4 .
29. THE DOM AND THE CSSOM
30. Source: High performance browser networking
31. CSS IN THE HEAD JS AT THE BOTTOM
32. TURBOLINKS
33. TURBOLINKS
34. CSS and the critical path Inline the CSS required for above the fold in the head Load the rest at the bottom Patrick Hamann on CSS and the critical path The Guardian team load CSS from localStorage Critical path CSS generator
35. IMAGES
36. LOSSLESS COMPRESSION
37. Assets Get the asset pipeline to do it! sprockets-image_compressor
38. Uploads Plugins! paperclip-optimizer carrierwave-imageoptimizer
39. PROGRESSIVE JPEGS
40. Source: Book of speed
41. Assets Get the asset pipeline to do it! image_optim
42. Paperclip h a s _ a t t a c h e d _ f i l e : i m a g e , { : s t y l e s = > { : p r o g r e s s i v e = > ' 1 x 1 < ' } , : c o n v e r t _ o p t i o n s = > { : p r o g r e s s i v e = > ' - i n t e r l a c e P l a n e ' } } 0 1 . 0 2 . 0 3 . 0 4 . 0 5 . 0 6 . 0 7 . 0 8 .
43. INLINING
44. Inlining rails-sass-images . m a i l a { b a c k g r o u n d - i m a g e : i n l i n e( " s v g / m a i l . s v g " ) ; } 0 1 . 0 2 . 0 3 .
45. HTTP 2.0
46. SPDY
47. HTTP 2.0/SPDY Features •  Single connection - multiplexed streams •  Request prioritization •  Server push
49. Fixing for SPDY •  Stop concatenating/inlining
50. THANKS
51. Questions? @philnash philnash@twilio.com