This talk is about optimizing your ruby and rails code. It focuses on the basics. Too many times people focus on using fun tools. Before you attack the fun stuff you should tackle the low hanging fruit. ror-e.com

1. Optimize The Obvious By: David Henner

2. www.ror-e.com drhenner @drhenner drhenner@yahoo.com

3. What do you think of when your boss asks you to: Optimize the site?

4. This talk isn’t about the fun stuff.

5. N + 1

6. When to use joins and includes

7. Looking at the Log File

8. Bad code that needs Refactoring.

9. Understanding your Bottlenecks

10. Add some RAM

11. Upgrade to Ruby 1.9.2

12. Use Constants WISELY

13. Optimize Images

14. Configure your Database

15. MySQL MyCNF file

16. Add Indexes

17. Only index The First 10 Characters

18. Name Wisely

19. STI type. Should be named As short as Possible

20. Use a CDN for Js & CSS

21. Compress Js & CSS

22. NOW LET’S TALK

23. N + 1

24. Who doesn’t know what an N + 1 query is?

25. Look at your LOG file

26. Modify your Queries @user = User.find(1) @user.groups.each do |group| group.method end @user = User.find(1, :includes => :groups) or @user = User.includes(:groups).find(1)

27. When to use joins and includes

28. Take a look at the RailsCast http://railscasts.com/episodes/181-include-vs-joins Use includes if you need to use the method on the associated model Use joins if you need to filter the objects loaded by SQL.

29. Looking at the Log File

30. N + 1

31. Deprecation Warnings

32. SLOW QUERIES Is this acceptable? ANSWER == Maybe

33. Bad code that needs Refactoring.

34. You might not be this bad

35. Know your API If you are doing something that you think should be part of ruby. It probably is. inject map join compact uniq DON’T RECREATE THESE METHODS (maybe inject but….)

36. INJECT SUCKS when…. object.inject({}) do |h, new_h| new_h[h.id] = h.some_method new_h end new_array = Object.map do |obj| [obj.id , obj.some_method] end Hash[new_array]

37. Don’t over-use Before_filters

38. Class SomeController < ActionController::Base def edit @post = Post.find(id) form_info end def update @post = Post.find(id) if @post.update_attributes(params[:post]) redirect_to :action => :index else form_info render :edit end end end private defform_info @states = State.find(:all).map{|s| [s.name, s.id]} end end

39. Understanding your Bottlenecks

40. You don’t need to measure performance on the page that takes 30 seconds to load!!

41. Add some RAM

42. It is easy and much cheaper than 10 / 20 or 100 hoursof a developer’s time

43. Upgrade to Ruby 1.9.2

45. You need to make sure that your Gemfile specifies that the ruby-debug19 gem is available in both the test and development environments by specifying it using group :test, :development in the Gemfile

46. 1.9.2 doesn’t support the use of a : in a when clause of a case statement any more

47. Hash#key has been removed and replaced with Hash#index

49. WHAT THE HELL DOES 1 MEAN!!!

50. WHAT THE HELL DOES 1 MEAN!!! OOPS that should be true.

51. Optimize Images

52. http://www.ror-e.com/posts/6-optimize-your-images Non-optimized Images can add 85% more page weight!!

53. Configure your Database

54. MySQL

55. http://blog.codesherpas.com/on_the_path/2011/03/tuning-mysql.html MyCNF Use INNOdb(transactions)

57. innodb_log_buffer_size

58. innodb_thread_concurrency

60. your best dollars spent will be on more ram

61. Set the value to about 2.5Gig less than your system RAM If you share your DB with memcached or passenger or anything else you need to set this value to have less RAM

62. http://blog.codesherpas.com/on_the_path/2011/03/tuning-mysql.html Innodb_log_buffer_size Start with 4 megabytes and adjust up

63. http://blog.codesherpas.com/on_the_path/2011/03/tuning-mysql.html innodb_thread_concurrency Set this value to 2x the number of cpu cores your server has

64. http://blog.codesherpas.com/on_the_path/2011/03/tuning-mysql.html Innodb_flush_method Set to O_DIRECT as long as you aren't running on a storage-area-network Otherwise READ the DOCs: http://dev.mysql.com/doc/refman/5.1/en/innodb-parameters.html#sysvar_innodb_flush_method

65. Add Indexes

67. Don’t forget to index strings

68. Don’t index the whole string

69. Index the first 10 charactersexecute('CREATE INDEX users_last_name_ten ON users (last_name(8));') execute('CREATE UNIQUE INDEX users_email_ten ON users (email(10));')

70. Name Wisely

71. STI type. Should be named As short as Possible

73. Your Model will be NameSpace::ModelName

75. Use a CDN for Js & CSS

76. Config CDN http://asherbond.com/blog/2009/10/22/ building-rails-applications-for-scale-using-cloud-infrastructure/

77. Compress Js & CSS

78. Jammitvs Asset Packager Both work. I like Jammit. Asset Packager works on Heroku http://www.viget.com/extend/static-asset-packaging-rails-3-heroku/

79. Use Rails profiler

80. Use Counter Cache

81. Counter Cache Great when you do things like: User.groups.size This value would be stored in the users table. http://railscasts.com/episodes/23-counter-cache-column

82. Use Background Processes & CRON

83. Background Processes Delayed Job resque Workling & Starling Rabbit MQ Lot of tasks don’t need to be real time. Give your users inboxes or emails with tokens to receive the info. Example: PDF generation, reports, cleanup of your cart.

84. COOL STUFF MemProf NewRelic Memcached Combine your SQL DB with noSQL

85. www.ror-e.com drhenner @drhenner drhenner@yahoo.com