My slides from a lightning talk I gave to SitePoint / Learnable devs earlier this year.

1. SPEEDING UP OUR APPS
(not start up time)
Thursday, 30 May 13

2. Thursday, 30 May 13

3. ?
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4. Based on several billion requests to wikia
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5. SPEEDING UP RESPONSES
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6. SPEEDING UP RESPONSES
• Template Caching
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7. SPEEDING UP RESPONSES
• Template Caching
• Partials
Thursday, 30 May 13

8. SPEEDING UP RESPONSES
• Template Caching
• Partials
• Actions
Thursday, 30 May 13

9. SPEEDING UP RESPONSES
• Template Caching
• Partials
• Actions
• Browser Caching
Thursday, 30 May 13

10. SPEEDING UP RESPONSES
• Template Caching
• Partials
• Actions
• Browser Caching
• CDN’s Everywhere
Thursday, 30 May 13

11. SPEEDING UP RESPONSES
• Template Caching
• Partials
• Actions
• Browser Caching
• CDN’s Everywhere
Thursday, 30 May 13

12. CACHING PARTIALS
• Self Expiring Cache Keys
• Nesting cached partials
• Touch Chains
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13. SELF EXPIRING CACHE KEYS
• Calls #cache_key on @user
• [class]/[id]-[updated_at]
• ‘users/2-20130220103049’
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14. CONTEXT IS KING
• Provide a unique key for each context
• Increment version when you change the html.
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15. TOUCH CHAINS
• Sets the parent model’s #updated_at toTime.now
• Touch parents, not children
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16. TOUCH CHAINS
LessonView LessonView LessonView
Enrollment Enrollment
User
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17. NESTED CACHED PARTIALS
• Update enrollment = n-1 partials still cached.
• Parent cache expired, but uses many nested caches = quick to
rebuild
Thursday, 30 May 13

18. SPEEDING UP RESPONSES
• Template Caching
• Partials
• Actions
• Browser Caching
• CDN’s Everywhere
Thursday, 30 May 13

19. PAGE CACHING
• Saves entire page to xyz.html in public
• Can serve up as gzipped
• Fast!
• Generally useless for anything but public static content
Thursday, 30 May 13

20. ACTION CACHING
• Same as page caching but allows before filters
• Caches to the cache_store, not public folder
Thursday, 30 May 13

21. EXPIRING PAGE / ACTION
CACHES
• Manual cache clearing != fun
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22. SPEEDING UP RESPONSES
• Template Caching
• Partials
• Actions
• Browser Caching
• CDN’s Everywhere
Thursday, 30 May 13

23. CONDITIONAL GETS
• Utilizes HTTP_IF_NONE_MATCH and IF_MODIFIED_SINCE
• Returns a HEAD 304 (not modified) response
• Does not render any content
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24. CONDITIONAL GETS
• 560ms
• 149ms
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25. A BETTERTOUCH CHAIN
• updated_at on User? CHANGES ALLTHETIME
• belongs_to :user,
touch: :enrollments_updated_at
• updated_at columns for various children
Thursday, 30 May 13

26. SPEEDING UP RESPONSES
• Template Caching
• Partials
• Actions
• Browser Caching
• CDN’s Everywhere
Thursday, 30 May 13

27. CDN’S EVERYWHERE
• Speed of light is a limiting factor
• AU <-> US 110ms
• AU <-> AU 40ms
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28. CDN’S AREN’T JUST FOR
STATIC CONTENT
SYN
SYNACK
RESPONSE
REQUEST
NO CDN
110ms
110ms
110ms
110ms
= 440ms
Thursday, 30 May 13

29. CDN’S AREN’T JUST FOR
STATIC CONTENT
SYN
SYNACK
RESPONSE
REQUEST
CDN
40ms
40ms
110ms
110ms
= 300ms (31% less)
CDN uses Keep Alive to
connect to origin (us)
Thursday, 30 May 13

30. SPEEDING UP RESPONSES
• Template Caching
• Partials
• Actions
• Browser Caching
• CDN’s Everywhere
• Bonus
Thursday, 30 May 13

31. ACTIVERECORD QUERY
CACHING
• Course Load (129.4ms) SELECT `courses`.* FROM `courses`
• CACHE (0.0ms) SELECT `courses`.* FROM `courses`
• Doesn’t work across requests
Thursday, 30 May 13

32. ACTIVERECORD QUERY
CACHING
• Caches AR query across requests in Redis
• Started GET "/visit/tag.gif" for 192.168.33.10 at 2013-02-20 11:28:28 +1100
Processing byVisitTagController#create as */*
[1m[36mUser Load (0.7ms)[0m [1mSELECT `users`.* FROM `users` WHERE `users`.`id` = 2 LIMIT 1[0m
[1m[35mFeature Load (0.4ms)[0m SELECT `features`.* FROM `features` WHERE `features`.`key` = 'intercept_renewal_failed_members' LIMIT 1
[1m[36mCACHE (0.0ms)[0m [1mSELECT `features`.* FROM `features` WHERE `features`.`key` = 'intercept_renewal_failed_members' LIMIT 1[0m
[1m[35mFeature Load (0.3ms)[0m SELECT `features`.* FROM `features` WHERE `features`.`key` = 'redirect_agreement_update' LIMIT 1
[1m[36mCACHE (0.0ms)[0m [1mSELECT `features`.* FROM `features` WHERE `features`.`key` = 'redirect_agreement_update' LIMIT 1[0m
[1m[35mFeature Load (0.4ms)[0m SELECT `features`.* FROM `features` WHERE `features`.`key` = 'testmode' LIMIT 1
[1m[36mCACHE (0.0ms)[0m [1mSELECT `features`.* FROM `features` WHERE `features`.`key` = 'testmode' LIMIT 1[0m
Completed 200 OK in 13ms (ActiveRecord: 1.8ms)
• Started GET "/visit/tag.gif" for 192.168.33.10 at 2013-02-20 11:28:28 +1100
Processing byVisitTagController#create as */*
Completed 200 OK in 13ms (ActiveRecord: 0ms)
Thursday, 30 May 13