Performance regressions in Ruby on Rails Core

Transcript

1. RAILSCLUB 2015 Kir Shatrov Performance regressions in Ruby on Rails

   core

2. @kirs @kirshatrov !"

3. None

4. Catching Performance Regressions in Rails

5. What’s a performance regression?

6. What’s a performance regression in Rails?

7. Page load 250ms → 4s

8. Case Study

9. 4.2rc1

10. None

11. 2 times slower

12. 4.2rc3

13. Faster framework = Faster app

14. Examples from Rails commits

15. Metrics

16. Timing & Allocations

17. Faster Methods = Faster App

18. start = Time.now.to_f sleep 5 ends = Time.now puts "it

    took #{ends - start}"

19. Allocations = GC work Less allocations = less GC work

20. before = GC.stat[:total_allocated_object] 10_000.times do { "key" => "value" }

    end after = GC.stat[:total_allocated_object] puts "allocated: #{after - before}"

21. Basic primitives

22. Examples from Rails commits String

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33. Examples from Rails commits Hash

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40. Optimize only “hot” code

41. Track the changes

42. The Idea to build a service

43. Track it with benchmarks

44. Any existing benchmarks?

45. None

46. Setup Discourse Populate records Start Unicorn with RAILS_ENV=production Make requests

    with Apache Bench to the list of endpoints Print timings and memory usage

47. Components to benchmark activerecord activemodel actionview actioncontroller activesupport

48. 3.2 – 4.0 – 4.1 – 4.2

49. higher is faster

50. higher is faster

51. higher is faster

52. None

53. ActiveRecord Finders require_relative 'support/activerecord_base.rb' require_relative 'support/benchmark_rails.rb' User.create!(name: 'kir', email: 'shatrov@me.com')

    m = Benchmark.rails(100, "activerecord/#{db_adapter}/finders") do User.find(1) end puts m.to_json

54. Disable GC is necessary Warm up the code Make N

    iterations Calculate the mean timing and object allocations

55. ActiveRecord::Base#create require_relative 'support/activerecord_base.rb' require_relative 'support/benchmark_rails.rb' fields = { name: "Kir",

    notes: "Note", created_at: Date.today } Benchmark.rails(1000, "activerecord/#{db_adapter}/create") do Exhibit.create(fields) end

56. Correct benchmarks

57. Full app benchmark higher is faster

58. Full app benchmark before higher is faster

59. stackprof by Aman Gupta github.com/tmm1/stackprof

60. config/environments/production.rb

61. Full app benchmark after

62. ✅ Benchmarks

63. None
64. None

65. The Service

66. What do we want? See benchmark for every commit See

    benchmark for every PR Report to PR author (“activerecord became 2% slower”) See charts

67. railsperf The prototype of the service. Built in January

68. rubybench.org by Sam Saffron and Guo Xiang Tan “Alan”

69. None

70. 3.6GHz Intel® Xeon® E3-1270 v3 Quad-Core 4 x 8GB Micron

    ECC Samsung SSD 845DC EVO - 240 GB Sponsored hardware

71. ruby-bench + rails

72. github.com/rails/rails webhook web app docker server benchmark suite

73. None

74. github.com/ruby-bench web app docker files benchmark suite

75. Results

76. Running builds for Rails

77. Performance regressions caught

78. Overview What is a performance regression How to track them

    How to solve them How to write benchmarks Automate tracking!

79. How to track your app performance? Study how do Ruby

    objects work and how to treat them Write a Discourse-like benchmark and run it on Travis Subscribe to Rails Weekly

80. Ruby Under a Microscope

81. http://bit.ly/writing-fast-ruby

82. How to track your app performance? Study how do Ruby

    objects work and how to treat them Write a Discourse-like benchmark and run it on Travis Subscribe to Rails Weekly

83. Setup the app Populate records Start Unicorn with RAILS_ENV=production Make

    requests with Apache Bench to the list of endpoints Print timings and memory usage

84. How to track your app performance? Study how do Ruby

    objects work and how to treat them Write a Discourse-like benchmark and run it on Travis Subscribe to Rails Weekly

85. Спасибо! @kirs @kirshatrov @evilmartians evilmartians.com