Using JRuby: What, Why, When, and How

Transcript

1. Using JRuby:
   
   
   What, Why, When, and How
   Charles Oliver Nutter
   
   
   @headius
   

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2. Thank You Yarden!
   • Yarden Laifenfeld could not be here
   
   
   • Check out her JRuby talk!
   
   
   • "Ruby & JVM: A Love Story"
   
   
   • Really cool talk about her
   experiences using and building
   apps with JRuby!
   
   
   • @YardenLaif
   

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3. View Slide

4. Cheers to Tom Enebo
   • We co-lead JRuby since 2006
   
   
   • Almost 16 years working together!
   
   
   • So many conferences!
   
   
   • So many beers!
   
   
   • @[email protected]
   
   
   • @tom_enebo on Twitter
   

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5. View Slide

6. What is JRuby?
   • An implementation of Ruby atop the Java Virtual Machine
   
   
   • Ruby implementation
   fi
   rst, JVM language second
   
   
   • Many bene
   fi
   ts from JVM ecosystem
   
   
   • Ruby code should "just work"
   
   
   • Different extension API, no forking, parallel threads
   
   
   • https://www.jruby.org/
   

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8. Ruby Compatibility
   • JRuby 9.4 is out now!
   
   
   • Ruby 3.1 compatible, language feature-complete
   
   
   • Most of core, stdlib features from 2.7 to 3.1 released in 9.4.0.0
   
   
   • JRuby 9.3 (Ruby 2.6 compat)
   
   
   • Maintenance through 2023 as needed
   
   
   • Compatibility before performance!
   
   
   • Now we can refocus on optimization again
   

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9. Why Ruby on JVM?
   • Widely deployed and widely supported runtime
   
   
   • Excellent JIT, GC, concurrency, and platform support
   
   
   • Tens of thousands of libraries
   
   
   • Rich tools for monitoring, pro
   fi
   ling, debugging
   
   
   • "Write once, run anywhere": JRuby works on many platforms
   

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10. JVM Tools and GC
    

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11. Parallel and Concurrent
    

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12. Fun Stuff
    event(:player_egg_throw) do |e|
    e.hatching = true
    e.num_hatches = 120
    e.player.mesg "hatched"
    end
    Purugin
    

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13. Getting Started
    

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14. View Slide

15. JRuby Install
    • Install a JDK
    
    
    • Java 11+ recommended, there's many distributions out there
    
    
    • Java 8 supported for 9.4 and lower
    
    
    • Install JRuby
    
    
    • Recommended: system package, Ruby installer, Docker image
    
    
    • Download tarball/zip or Windows installer
    

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16. Test it out!
    [] ~ $ rvm use jruby
    
    
    Using /Users/headius/.rvm/gems/jruby-9.4.0.0
    
    
    [] ~ $ irb
    
    
    :001 > runtime = java.lang.Runtime.runtime
    
    
    => #
    
    
    :002 > runtime.available_processors
    
    
    => 8
    
    
    :003 > runtime.free_memory
    
    
    => 91420584
    
    
    :004 >
    

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17. JRuby on Rails
    

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18. JRuby on Rails?
    • JRuby has run Rails since 2007!
    
    
    • "Are there JRuby users running Rails applications?"
    
    
    • Oh yes! And at large scale!
    
    
    • Bene
    fi
    t from the JVM, libraries, languages
    
    
    • The best way to scale large Rails apps today!
    

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19. --- testapp_mri_pg/Gemfile
    
    
    +++ testapp_jruby_pg/Gemfile
    
    
    -# Use postgresql as the database for Active Record
    
    
    -gem 'pg', '>= 0.18', '< 2.0'
    
    
    +# Use jdbcpostgresql as the database for Active Record
    
    
    +gem 'activerecord-jdbcpostgresql-adapter'
    
    
    # See https://github.com/rails/execjs#readme for more supported runtimes
    
    
    -# gem 'mini_racer', platforms: :ruby
    
    
    -
    
    
    +gem 'therubyrhino'
    
    
    group :development do
    
    
    - # Spring speeds up development...
    
    
    - gem 'spring'
    
    
    - gem 'spring-watcher-listen', '~> 2.0.0'
    
    
    end
    
    
    Minimal Con
    fi
    g Diffs
    --- testapp_mri_pg/config/database.yml
    
    
    +++ testapp_jruby_pg/config/database.yml
    
    
    @@ -65,5 +81,7 @@
    
    
    production:
    
    
    <<: *default
    
    
    database: rails_prod
    
    
    + host: localhost
    
    
    + port: 5432
    
    
    username: rails_prod
    
    
    password: rails_prod
    --- testapp_mri_pg/config/puma.rb 2019-04-19 04:48:51.425474315 +0000
    
    
    +++ testapp_jruby_pg/config/puma.rb 2019-04-17 08:56:53.529154189 +0000
    
    
    @@ -4,7 +4,7 @@
    
    
    # the maximum value specified for Puma. Default is set to 5 threads for minimum
    
    
    # and maximum; this matches the default thread size of Active Record.
    
    
    #
    
    
    -threads_count = ENV.fetch("RAILS_MAX_THREADS") { 2 }
    
    
    +threads_count = ENV.fetch("RAILS_MAX_THREADS") { 20 }
    
    
    threads threads_count, threads_count
    
    
    
    
    # Specifies the `port` that Puma will listen on to receive requests; default is 3000.
    
    
    @@ -21,7 +21,7 @@
    
    
    # Workers do not work on JRuby or Windows (both of which do not support
    
    
    # processes).
    
    
    #
    
    
    -workers ENV.fetch("WEB_CONCURRENCY") { 2 }
    
    
    +# workers ENV.fetch("WEB_CONCURRENCY") { 2 }
    
    
    
    
    # Use the `preload_app!` method when specifying a `workers` number.
    
    
    # This directive tells Puma to first boot the application and load code
    

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20. Rails 7
    • Rails 7 works on JRuby 9.4!
    
    
    • ActiveRecord for JRuby needs some updates
    
    
    • Mostly small changes to our ActiveRecord JDBC adapter
    
    
    • Performance and compatibility looking good!
    

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21. Rails 7
    actioncable: 203 runs, 921 assertions, 0 failures, 10 errors
    actionmailbox: 92 runs, 238 assertions, 0 failures, 0 errors
    actionmailer: 230 runs, 516 assertions, 0 failures, 1 errors
    actionpack: 3550 runs, 16802 assertions, 1 failures, 1 errors
    actiontext: 80 runs, 145 assertions, 7 failures, 2 errors
    actionview: 2424 runs, 5395 assertions, 2 failures, 4 errors
    activejob: 368 runs, 837 assertions, 0 failures, 0 errors
    activemodel: 966 runs, 2853 assertions, 5 failures, 0 errors
    activestorage: 392 runs, 1121 assertions, 0 failures, 0 errors
    activesupport: 5188 runs, 12926 assertions, 43 failures, 28 errors
    99% passing!
    

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22. Failure:
    TimeWithZoneTest#test_minus_with_time_precision [activesupport/
    test/core_ext/time_with_zone_test.rb:340]:
    Expected: 86399.999999998
    Actual: 86399.99999999799
    😩
    

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23. activerecord-jdbc-adapter
    • Version-matched to Rails
    
    
    • 60.0 for Rails 6.x, 70.0 for Rails 7.x, etc
    
    
    • 70.0 in progress
    
    
    • sqlite, mysql working pretty well, gems are out there
    
    
    • 7745 runs, 25040 assertions, 32 failures, 14 errors, 19 skips
    
    
    • postgresql needs more updates, coming soon
    

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24. Performance
    

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25. What Matters to You?
    • Straight-line performance?
    
    
    • High concurrency?
    
    
    • Startup time?
    
    
    • Warmup time?
    
    
    • Memory size?
    
    
    • Optimizing for only one of these can penalize the others
    

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26. Benchmarks
    • Benchmarks are very situational
    
    
    • What looks good in a microbench may not translate to production
    
    
    • Three example benchmarks
    
    
    • railsbench, small Rails blog on SQLite, no web server, tight loop
    
    
    • Rails blog on MySQL, end to end through Puma
    
    
    • ActiveRecord reads and updates
    

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27. railsbench
    • Based on simple scaffolded blog app
    
    
    • SQLite database, single thread, all in one process
    
    
    • No web server, no connections, just loop on requests
    
    
    • Good for analyzing Rails core framework performance
    
    
    • Not great for real-world end-to-end measurement
    

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28. The Players
    • Ruby 3.1.2 with and without --yjit
    
    
    • Truf
    fl
    eRuby 22.2 JVM CE
    
    
    • Newer versions may be better
    
    
    • JRuby 9.4 on Java 17
    

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29. time to run 2000 requests (lower is better)
    0
    550
    1100
    1650
    2200
    Time
    1,460ms
    1,834ms
    1,704ms
    2,152ms
    CRuby 3.1 CRuby 3.1 yjit Tru
    ffl
    eRuby JRuby
    

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30. What You're Missing
    • Straight-line performance?
    
    
    • High concurrency?
    
    
    • Startup time?
    
    
    • Warmup time?
    
    
    • Memory size?
    

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31. Memory Footprint
    • More complex runtimes take more memory
    
    
    • Different GC strategies take more memory
    
    
    • CRuby has been optimized for startup time and memory use
    
    
    • Super valuable but may not help server apps
    

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32. Memory Footprint
    0
    750
    1500
    2250
    3000
    Memory
    900MB
    2,400MB
    80MB
    CRuby 3.1 Tru
    ffl
    eRuby JRuby
    

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33. Warmup Time
    • Optimizing runtimes just take longer to warm up
    
    
    • Code needs to be pro
    fi
    led, analyzed, compiled
    
    
    • GC needs to
    fi
    nd sweet spot for heap size, generations
    
    
    • Known issue, but we and JVM folks always try to improve
    
    
    • Pre-warm new deploys (or just accept it will start off slower)
    
    
    • JVM tooling to bootstrap into a warm VM
    

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34. Warmup Over Time
    0ms
    450ms
    900ms
    1350ms
    1800ms
    Iteration (2000 requests each)
    1 2 3 4 5 6 7 8 9 10
    CRuby 3.1 yjit
    

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35. Warmup Over Time
    0ms
    5000ms
    10000ms
    15000ms
    20000ms
    Iteration (2000 requests each)
    1 2 3 4 5 6 7 8 9 10
    JRuby
    

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36. Warmup Over Time
    0ms
    5000ms
    10000ms
    15000ms
    20000ms
    Iteration (2000 requests each)
    1 2 3 4 5 6 7 8 9 10
    CRuby 3.1 yjit JRuby
    

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37. Warmup Over Time
    0ms
    6000ms
    12000ms
    18000ms
    24000ms
    Iteration (2000 requests each)
    1 2 3 4 5 6 7 8 9 10
    Tru
    ffl
    eRuby
    

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38. Warmup Over Time
    0ms
    7500ms
    15000ms
    22500ms
    30000ms
    Iteration (2000 requests each)
    1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69
    CRuby 3.1 yjit Tru
    ffl
    eRuby JRuby
    

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39. Benchmarks Lie
    • The only benchmark that matters is your code
    
    
    • Your code is probably not requesting the same posts in a loop
    
    
    • We can make this a bit more real with full end-to-end
    
    
    • Puma web server, MySQL backend
    
    
    • External request driver (siege)
    
    
    • Max out CPU (high concurrency)
    

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40. End-to-end Rails Blog
    • Scaffolded "blog" application on MySQL
    
    
    • Local i7 laptop
    
    
    • CRuby 3.1: 16 workers, 2 threads each
    
    
    • JRuby 9.4: 32 threads
    
    
    • Truf
    fl
    eRuby: 32 threads but had issues
    

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41. Setup
    • Local everything including benchmark driver
    
    
    • MySQL in a Docker container
    
    
    • Scaffolded app is super minimal
    
    
    • Using siege: 16 concurrent, 10s intervals, benchmark mode
    
    
    • Warmup time is a thing...
    

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42. requests per second (higher is better)
    0rps
    1500rps
    3000rps
    4500rps
    6000rps
    3m
    5,160rps
    668rps
    2,361rps
    2,070rps
    CRuby 3.1 CRuby 3.1 yjit Tru
    ffl
    eRuby JVM CE JRuby
    

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43. 0MB
    1500MB
    3000MB
    4500MB
    6000MB
    1,400MB
    6,000MB
    1,520MB
    Ruby 3.1 Tru
    ffl
    eRuby JRuby
    

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44. 0MB
    400MB
    800MB
    1200MB
    1600MB
    950MB
    1,400MB
    1,520MB
    Ruby 3.1 JRuby JRuby with max heap
    

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45. Requests per second, 10s siege runs (higher is better)
    0
    1500
    3000
    4500
    6000
    1 2 3 4 5 6 7 8 9 10
    CRuby 3.1 CRuby 3.1 yjit JRuby
    

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46. ActiveRecord Performance
    • Steady improvement over the years
    
    
    • Lots of work to slim down, use prepared statements, etc
    
    
    • Still a pretty heavy framework
    
    
    • JRuby performance has steadily increased
    
    
    • Thanks in part to JVM improvements!
    
    
    • Numbers using local MySQL via Docker
    

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47. Select Performance
    select
    Iterations per second
    0
    1250
    2500
    3750
    5000
    binary boolean datetime string text *
    3,974
    4,798
    4,853
    4,499
    4,569
    4,798
    2,410
    2,584
    2,480
    2,674
    2,713
    2,630
    CRuby 3.1 JRuby 9.4
    

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48. Update Performance
    Update speci
    fi
    c typed column and save!
    Iterations per second
    0
    5000
    10000
    15000
    20000
    binary boolean datetime string text timestamp
    16,407
    18,580
    18,969
    14,630
    18,934
    19,751
    7,615
    8,406
    8,341
    6,507
    8,509
    8,491
    

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49. True Story
    • Large Rails application using 40 xlarge on EC2
    
    
    • 40 worker processes per server
    
    
    • 100k-150k req/min, 50-75ms response times
    
    
    • Migrated app to JRuby, made more use of threading
    
    
    • Down to 10 xlarge, 75% cost reduction
    
    
    • Consistently over 150k req/min, 30ms response times
    

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50. Wrapping Up
    

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51. JRuby Future
    • JRuby 9.4 is out!
    
    
    • You can help us by trying it and reporting issues
    
    
    • Maybe submit a PR?
    
    
    • Big optimization work coming the rest of this year
    
    
    • Many call types do not optimize, no splitting, lots of big plans
    
    
    • Upcoming JVM features: native
    fi
    bers, built-in FFI, new JITs and GCs
    

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52. JRuby on Rails Future
    • Rails 6 support is pretty stable
    
    
    • Rails 7 support is looking great!
    
    
    • As your app grows, JRuby can help you scale
    
    
    • Reduce resources, save money
    
    
    • Let's talk about running your app on JRuby!
    

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53. Thank You!
    • Charles Oliver Nutter
    
    
    • [email protected]
    
    
    • @headius(@mastodon.social)
    
    
    • https://github.com/jruby/jruby
    
    
    • https://www.jruby.org
    

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