Reactive Ruby - building web apps with JRuby and Ratpack

Slides for my talk about reactive Ruby and building high performant web apps with JRuby and Ratpack.io at the RUG::B meetup 2017/03.

Transcript

1. Reactive Ruby
   

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2. Reactive Ruby
   - web apps with JRuby and Ratpack -
   

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3. max
   

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4. max
   ! klappradla
   " klappradla
   

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8. limits
   

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9. $
   GIL
   

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10. blocking IO
    

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11. client server db
    

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12. client server db
    ⏳
    ⏳
    

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14. non-blocking IO
    

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15. client server db
    

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16. client server db
    ⏳
    

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20. “…gain the performance and
    concurrency benefits of Java without
    writing any Java code or XML”
    -joe kutner-
    

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21. # ratpack.io
    

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22. “It is built on Java 8, Netty and
    reactive principles"
    # netty.io
    -ratpack.io-
    

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23. “It provides just enough for writing
    practical, high performance, apps.”
    -ratpack.io-
    

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24. #reactive )
    

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25. “So let's cut the bullshit.

    Reactive programming is programming with
    asynchronous data streams”
    - @andrestaltz-
    # The introduction to Reactive Programming you've been missing
    

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26. iterator ♻
    +
    observer +
    

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27. “non-blocking communication allows recipients
    to only consume resources while active, leading
    to less system overhead”
    - reactivemanifesto-
    # reactivemanifesto.org
    

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28. # reactivex.io/
    Rx* libs ,
    

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29. # Get evens and square each
    some_source
    .select { |x| x.even? }
    .map { |x| x * x }
    .subscribe { |x| puts x.to_s }
    # github.com/ReactiveX/RxRuby
    

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30. ratpack -
    

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31. public class Main {
    public static void main(String... args) throws Exception {
    RatpackServer.start(server -> server
    .handlers(chain -> chain
    .get(ctx -> ctx.render("Hello World"))
    )
    );
    }
    }
    # ratpack.io/manual/current/launching.html#launching
    

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32. # Gemfile
    gem 'jbundler'
    # Jarfile
    jar 'io.ratpack:ratpack-core', '1.4.0'
    jar 'org.slf4j:slf4j-simple', '1.7.20'
    

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33. $ bundle install
    

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34. $ bundle exec jbundle install
    

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35. # github.com/klappradla/jruby_ratpack_examples/hello_world
    require 'java'
    require 'jruby/core_ext'
    require 'bundler/setup'
    Bundler.require
    java_import 'ratpack.server.RatpackServer'
    RatpackServer.start do |server|
    server.handlers do |chain|
    chain.get do |ctx|
    ctx.render('Hello World from Ratpack / JRuby')
    end
    end
    end
    

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37. blocking IO ?
    

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38. “A promise is a representation of a value which
    will become available later. Methods such as
    map(Function) […] allow a pipeline of
    “operations” to be specified, that the value will
    travel through as it becomes available.”
    -ratpack docs-
    # ratpack.io/manual/current/api/ratpack/exec/Promise.html
    

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39. # ratpack.io/manual/current/async.html#performing_blocking_operations_eg_io
    java_import 'ratpack.server.RatpackServer'
    java_import 'ratpack.exec.Blocking'
    require 'json'
    RatpackServer.start do |server|
    server.handlers do |chain|
    chain.get('music') do |ctx|
    Blocking
    .get { DB[:albums].all }
    .then { |data| ctx.render(JSON.dump(data))}
    end
    end
    end
    

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40. RatpackServer.start do |server|
    server.handlers do |chain|
    chain.get('music') do |ctx|
    Blocking
    .get { DB[:albums].all }
    .then { |data| ctx.render(JSON.dump(data))}
    end
    end
    end
    

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41. RatpackServer.start do |server|
    server.handlers do |chain|
    chain.get('music') do |ctx|
    Blocking
    .get { DB[:albums].all }
    .map { |data| JSON.dump(data) }
    .then { |data| ctx.render(data)}
    end
    end
    end
    

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42. non-blocking HTTP ?
    

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43. class Server
    def self.run
    RatpackServer.start do |server|
    server.handlers do |chain|
    chain.all(RequestLogger.ncsa)
    chain.get('music', Handler::Music)
    chain.get('planets', Handler::Planets)
    chain.all(Handler::NotFound)
    end
    end
    end
    end
    # github.com/klappradla/jruby_ratpack_examples/http_example
    

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44. # github.com/klappradla/jruby_ratpack_examples/http_example
    module Handler
    class Base
    def self.handle(ctx)
    new(ctx).handle
    end
    def initialize(ctx)
    @ctx = ctx
    end
    attr_reader :ctx
    def handle
    raise NotImplementedError
    end
    end
    end
    

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45. # github.com/klappradla/jruby_ratpack_examples/http_example
    java_import 'ratpack.http.client.HttpClient'
    require_relative 'base'
    module Handler
    class Planets < Base
    URL = java.net.URI.new('http://swapi.co/api/planets')
    def handle
    ctx
    .get(HttpClient.java_class)
    .get(URL)
    .map { |resp| resp.get_body }
    .map { |body| body.get_text }
    .then { |data| render(data) }
    end
    private
    def render(data)
    resp = ctx.get_response
    header = 'application/json;charset=UTF-8'
    resp.send(header, data)
    end
    end
    end
    

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47. # github.com/klappradla/jruby_ratpack_examples/sinatra
    

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48. # github.com/klappradla/jruby_ratpack_examples/benchmarks
    # Sinatra
    Running 30s test @ http://localhost:5050
    4 threads and 100 connections
    Thread Stats Avg Stdev Max +/- Stdev
    Latency 284.63ms 358.37ms 1.95s 85.07%
    Req/Sec 145.18 72.13 434.00 65.54%
    16392 requests in 30.08s, 64.94MB read
    Socket errors: connect 0, read 0, write 0, timeout 72
    Non-2xx or 3xx responses: 1
    Requests/sec: 545.00
    Transfer/sec: 2.16MB
    # Ratpack
    Running 30s test @ http://localhost:5050
    4 threads and 100 connections
    Thread Stats Avg Stdev Max +/- Stdev
    Latency 150.36ms 228.64ms 1.86s 88.18%
    Req/Sec 338.10 129.48 710.00 71.18%
    32746 requests in 30.08s, 127.09MB read
    Requests/sec: 1088.56
    Transfer/sec: 4.22MB
    

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49. # github.com/klappradla/jruby_ratpack_examples/benchmarks
    # Sinatra
    Running 30s test @ http://localhost:5050
    4 threads and 100 connections
    Thread Stats Avg Stdev Max +/- Stdev
    Latency 284.63ms 358.37ms 1.95s 85.07%
    Req/Sec 145.18 72.13 434.00 65.54%
    16392 requests in 30.08s, 64.94MB read
    Socket errors: connect 0, read 0, write 0, timeout 72
    Non-2xx or 3xx responses: 1
    Requests/sec: 545.00
    Transfer/sec: 2.16MB
    # Ratpack
    Running 30s test @ http://localhost:5050
    4 threads and 100 connections
    Thread Stats Avg Stdev Max +/- Stdev
    Latency 150.36ms 228.64ms 1.86s 88.18%
    Req/Sec 338.10 129.48 710.00 71.18%
    32746 requests in 30.08s, 127.09MB read
    Requests/sec: 1088.56
    Transfer/sec: 4.22MB
    

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50. 
    # github.com/jruby/jruby/wiki/AboutJRuby
    # github.com/klappradla/jruby_ratpack_examples
    # blog.heroku.com/reactive_ruby_building_real_time_apps_with_jruby_and_ratpack
    

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