Performance - When, What and How
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Vitaly Kushner discusses performance optimization in Rails applications, emphasizing the importance of speed, throughput, and scalability as user bases grow. He provides tools and techniques for measurement and improvement, such as Yahoo YSlow, Google PageSpeed, and various code optimizations, while cautioning against premature optimizations due to limited time and budget. The presentation highlights the need for a scalability plan and encourages celebrating growth milestones, even if performance issues arise.
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Performance - When, What and How
- 1. Rails Performance When, What and How Vitaly Kushner @vkushner
- 2. Vitaly Kushner programming since middle 80s professionally since early 90s Rails since 2005 founded Astrails in 2008
- 4. performance
- 6. performance
- 7. performance • raw speed • throughput • scalability • end-user
- 8. No time to dive into details
- 9. When to optimize? and when not to.
- 10. what to do with 1M users
- 11. Celebrate! you’ve made it.
- 13. NOT because of performance problems
- 14. 1 million users
- 15. first 1000 users!
- 16. have scalability problem?
- 17. GREAT! because it means you grow fast
- 18. later
- 19. Scalability Plan • understand the limits • know your next step
- 20. performance does it matter?
- 21. YES! performance is very important
- 22. Is 1% a lot? yes, if you are Google.
- 23. Why not to optimize anyway?
- 24. time and budget usually limited
- 25. Measure You can not improve what you do not measure.
- 26. Tools • Yahoo Yslow http://developer.yahoo.com/yslow/ • Google PageSpeed https://developers.google.com/speed/pagespeed • NewRelic - http://newrelic.com • httperf & ab • Blitz.io
- 27. limit number of records from the database
- 29. Instantiation Breakdown: Total: 14 | User: 4 | Experience: 3 | Location: 3 | Interest: 3 | Admin: 1
- 30. limit number of queries prevent 1+N queries problem
- 32. N+1 Query detected Experience => [:interest] Add to your finder: :include => [:interest]
- 33. define indexes can be done later
- 35. limit number of http requests consolidate assets assets pipeline makes it easy
- 36. css at the top js at the bottom improves perceived page speed
- 37. low level hacks • replace :include with :join • explicit :select
- 38. not recommened
- 39. Maintainability usually better then speed
- 40. low hanging fruits • compress and http cache assets • CDN libraries • image sprites • bundle images into CSS • CDN for all static assets
- 42. real performance problem?
- 43. next time...
- 44. Thank you! Slides and video will be published at http://astrails.com/blog Vitaly Kushner @vkushner