Improving CVAR Performance in Ruby 3.1

Transcript

1. Improving CVAR
   performance in
   Ruby 3.1
   EILEEN M. UCHITELLE | @eileencodes
   

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2. Thank You RubyConf
   organizers, staff, &
   attendees —
   

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3. Eileen M. Uchitelle
   @eileencodes
   

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4. Core Team
   Member
   of Ruby on Rails
   

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5. f Principal Software
   Engineer
   at GitHub
   

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6. Improving CVAR
   performance in
   Ruby 3.1
   

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7. What is a CVAR?
   

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8. What is a CVAR?
   class MyClass
   @@cvar = 1
   def self.read_cvar
   @@cvar
   end
   end
   

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9. What is a CVAR?
   class MyClass
   @@cvar = 1
   def self.read_cvar
   @@cvar
   end
   end
   Writer
   

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10. What is a CVAR?
    class MyClass
    @@cvar = 1
    def self.read_cvar
    @@cvar
    end
    end
    Reader
    

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11. How does CVAR
    inheritance work?
    

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12. IVAR inheritance
    class Dog
    attr_reader :name, :owner
    def initialize
    @name = "Arya"
    @owner = "Eileen"
    end
    end
    class Puppy < Dog
    def initialize
    @name = "Sansa"
    end
    end
    

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13. IVAR inheritance
    > Dog.new.name
    => "Arya"
    > Dog.new.owner
    => "Eileen"
    > Puppy.new.name
    => "Sansa"
    > Puppy.new.owner
    => nil
    

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14. CVAR inheritance
    class Dog
    @@name = "Arya"
    @@owner = "Eileen"
    def self.name
    @@name
    end
    def self.owner
    @@owner
    end
    end
    class Puppy < Dog
    @@name = "Sansa"
    end
    

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15. CVAR inheritance
    > Dog.owner
    => "Eileen"
    > Puppy.owner
    => "Eileen"
    

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16. CVAR inheritance
    > Dog.owner
    => "Eileen"
    > Puppy.owner
    => "Eileen"
    > Dog.name
    => "Sansa"
    

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17. CVAR inheritance
    > Dog.owner
    => "Eileen"
    > Puppy.owner
    => "Eileen"
    > Dog.name
    => "Sansa"
    > Puppy.name
    => "Sansa"
    🤔
    

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18. Puppy
    Object
    Dog
    Kernel
    BasicObject
    

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19. Puppy
    Dog
    Object
    Kernel
    BasicObject
    Stores
    @@name
    @@owner
    

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20. @@name "Sansa"
    RCLASS_IV_TBL
    Puppy
    Dog
    

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21. Understanding CVAR
    Overtaken
    

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22. CVAR Overtaken
    class Dog
    end
    class Puppy < Dog
    @@name = "Sansa"
    def self.name
    @@name
    end
    end
    

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23. CVAR Overtaken
    class Dog
    end
    class Puppy < Dog
    @@name = "Sansa"
    def self.name
    @@name
    end
    end
    class Dog
    @@name = "Arya"
    end
    

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24. CVAR Overtaken
    > Puppy.name
    => class variable @@name of Puppy is overtaken
    by Dog
    

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25. The deeper the
    inheritance chain the
    slower CVAR access is
    

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26. CVAR Benchmarks
    MODULES = ["A", ..."WWWW"]
    class One
    @@cvar = 1
    def self.cvar
    @@cvar
    end
    eval <<-EOM
    module #{MODULES.first}
    end
    include #{MODULES.first}
    EOM
    end
    

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27. CVAR Benchmarks
    class Thirty
    @@cvar = 1
    def self.cvar
    @@cvar
    end
    MODULES.take(30).each do |module_name|
    eval <<-EOM
    module #{module_name}
    end
    include #{module_name}
    EOM
    end
    end
    

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28. CVAR Benchmarks
    class OneHundred
    @@cvar = 1
    def self.cvar
    @@cvar
    end
    MODULES.each do |module_name|
    eval <<-EOM
    module #{module_name}
    end
    include #{module_name}
    EOM
    end
    end
    

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29. CVAR Benchmarks
    Benchmark.ips do |x|
    x.report "1 module" do
    One.cvar
    end
    x.report "30 modules" do
    Thirty.cvar
    end
    x.report "100 modules" do
    OneHundred.cvar
    end
    x.compare!
    end
    

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30. CVAR Benchmarks
    Warming up --------------------------------------
    1 module 1.231M i/100ms
    30 modules 432.020k i/100ms
    100 modules 145.399k i/100ms
    Calculating -------------------------------------
    1 module 12.210M (± 2.1%) i/s - 61.553M in 5.043400s
    30 modules 4.354M (± 2.7%) i/s - 22.033M in 5.063839s
    100 modules 1.434M (± 2.9%) i/s - 7.270M in 5.072531s
    Comparison:
    1 module: 12209958.3 i/s
    30 modules: 4354217.8 i/s - 2.80x (± 0.00) slower
    100 modules: 1434447.3 i/s - 8.51x (± 0.00) slower
    

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31. S
    CVAR Benchmarks
    Warming up --------------------------------------
    1 module 1.231M i/100ms
    30 modules 432.020k i/100ms
    100 modules 145.399k i/100ms
    Calculating -------------------------------------
    1 module 12.210M (± 2.1%) i/s - 61.553M in 5.043400s
    30 modules 4.354M (± 2.7%) i/s - 22.033M in 5.063839s
    100 modules 1.434M (± 2.9%) i/s - 7.270M in 5.072531s
    Comparison:
    1 module: 12209958.3 i/s
    30 modules: 4354217.8 i/s - 2.80x (± 0.00) slower
    100 modules: 1434447.3 i/s - 8.51x (± 0.00) slower 8.5x!
    

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32. Are CVARs really that
    common?
    

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33. CVARs in Rails
    module ActiveRecord
    module Core
    def self.configurations=(config)
    @@configurations = ActiveRecord::DatabaseConfigs.new(config)
    end
    self.configurations = {}
    def self.configurations
    @@configurations
    end
    end
    end
    

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34. CVARs in Rails
    module ActiveRecord
    module Core
    mattr_accessor :logger, instance_writer: false
    mattr_accessor :verbose_query_logs, instance_writer: false, default: false
    mattr_accessor :schema_format, instance_writer: false, default: :ruby
    mattr_accessor :dump_schemas, instance_writer: false, default: :schema_search_path
    mattr_accessor :dump_schema_after_migration, instance_writer: false, default: true
    end
    end
    

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35. CVARs in Rails
    > ActiveRecord::Base.ancestors.count
    => 73
    > ActionController::Base.ancestors.count
    => 71
    > ActiveJob.ancestors.count
    => 29
    

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36. Building a cache for
    CVARs
    

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37. View Slide

38. @@name "Sansa"
    RCLASS_IV_TBL RCLASS_CVC_TBL
    Dog
    

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39. @@name "Sansa"
    RCLASS_IV_TBL
    @@name
    RCLASS_CVC_TBL
    Dog
    

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40. @@name "Sansa"
    RCLASS_IV_TBL
    @@name Inline cache
    RCLASS_CVC_TBL
    Dog
    

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41. @@name "Sansa"
    RCLASS_IV_TBL
    @@name Inline cache
    RCLASS_CVC_TBL
    Dog pointer
    global_cvar_state
    Dog
    

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42. @@name "Sansa"
    RCLASS_IV_TBL
    @@name Inline cache
    RCLASS_CVC_TBL
    Dog pointer
    global_cvar_state
    Dog
    Puppy
    

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43. Puppy.name
    

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44. Puppy.name
    global_cvar_state == GET_GLOBAL_CVAR_STATE()
    

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45. Puppy.name
    Dog
    global_cvar_state == GET_GLOBAL_CVAR_STATE()
    

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46. Dog
    Puppy.name
    global_cvar_state == GET_GLOBAL_CVAR_STATE()
    @@name "Sansa"
    RCLASS_IV_TBL
    

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47. S
    CVAR Cache PR
    github.com/ruby/ruby/pull/4340
    

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48. Benchmarking
    performance
    

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49. S
    CVAR Benchmarks
    Warming up --------------------------------------
    1 module 1.231M i/100ms
    30 modules 432.020k i/100ms
    100 modules 145.399k i/100ms
    Calculating -------------------------------------
    1 module 12.210M (± 2.1%) i/s - 61.553M in 5.043400s
    30 modules 4.354M (± 2.7%) i/s - 22.033M in 5.063839s
    100 modules 1.434M (± 2.9%) i/s - 7.270M in 5.072531s
    Comparison:
    1 module: 12209958.3 i/s
    30 modules: 4354217.8 i/s - 2.80x (± 0.00) slower
    100 modules: 1434447.3 i/s - 8.51x (± 0.00) slower 8.5x!
    

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50. S
    CVAR Benchmarks
    Warming up --------------------------------------
    1 module 1.641M i/100ms
    30 modules 1.655M i/100ms
    100 modules 1.620M i/100ms
    Calculating -------------------------------------
    1 module 16.279M (± 3.8%) i/s - 82.038M in 5.046923s
    30 modules 15.891M (± 3.9%) i/s - 79.459M in 5.007958s
    100 modules 16.087M (± 3.6%) i/s - 81.005M in 5.041931s
    Comparison:
    1 module: 16279458.0 i/s
    100 modules: 16087484.6 i/s
    30 modules: 15891406.2 i/s
    No difference!
    

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51. S
    CVAR Benchmarks
    $ RAILS_ENV=production INTERVAL=100 WARMUP=1 BENCHMARK=10000 ruby bin/bench
    ruby 3.1.0dev (2021-06-04T00:24:57Z master 91c542ad05) [x86_64-darwin19]
    Warming up...
    Warmup: 1 requests
    Benchmark: 10000 requests
    Request per second: 615.1 [#/s] (mean)
    Percentage of the requests served within a certain time (ms)
    50% 1.57
    66% 1.68
    75% 1.74
    80% 1.78
    90% 1.91
    95% 2.06
    98% 2.36
    99% 2.67
    100% 35.15
    

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52. S
    CVAR Benchmarks
    $ RAILS_ENV=production INTERVAL=100 WARMUP=1 BENCHMARK=10000 ruby bin/bench
    ruby 3.1.0dev (2021-06-04T17:40:20Z add-cache-for.. 37c96af98b) [x86_64-darwin19]
    Warming up...
    Warmup: 1 requests
    Benchmark: 10000 requests
    Request per second: 657.1 [#/s] (mean)
    Percentage of the requests served within a certain time (ms)
    50% 1.46
    66% 1.56
    75% 1.63
    80% 1.68
    90% 1.82
    95% 2.01
    98% 2.28
    99% 2.50
    100% 35.13
    

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53. What did we
    learn?
    

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54. 🐞!
    

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55. S
    Feature Request
    

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56. Every OSS change
    has tradeoffs
    

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57. Every OSS change
    has tradeoffs
    

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58. Tradeoffs
    Increased complexity
    

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59. Tradeoffs
    Encourages more usage
    

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60. Tradeoffs
    Increased maintenance
    burden
    

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61. Every OSS change
    is a negotiation
    

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62. Negotiation
    CVARs aren't going
    anywhere
    

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63. Negotiation
    Demonstrate real-world
    improvements
    

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64. Negotiation
    Improve all applications by
    upgrading
    

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65. Let's do more of this
    

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66. Let's do more of this
    By learning C
    

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67. Let's do more of this
    By reading "Ruby Under a
    Microscope"
    

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68. Let's do more of this
    By making small changes
    

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69. Making Ruby better
    benefits everyone
    

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70. Making Ruby better
    benefits you
    

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71. Let's go make Ruby
    better, together
    

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72. Thank You RubyConf!
    EILEEN M. UCHITELLE | @eileencodes
    

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