EM vs Node

Transcript

1. Is
   EventMachine
   a worthy alternative to
   Node.js
   

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2. Andrew Nesbitt
   github.com/andrew
   @teabass
   

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3. forwardtechnology.co.uk
   

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4. Node.js
   nodejs.org
   

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5. "Evented I/O for V8 JavaScript"
   Concurrent, scalable network programs
   Speaks HTTP natively
   Asynchronous, non-blocking by design
   

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6. "Realtime" applications
   Proxy servers
   Web APIs
   What would you use it for?
   

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7. Synchronous I/O
   

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8. Asynchronous I/O
   

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9. var p_client = new Db('integration_tests_20', new Server("127.0.0.1", 27017, {}),
   {'pk':CustomPKFactory});
   p_client.open(function(err, p_client) {
   p_client.dropDatabase(function(err, done) {
   p_client.createCollection('test_custom_key', function(err, collection) {
   collection.insert({'a':1}, function(err, docs) {
   collection.find({'_id':new ObjectID("aaaaaaaaaaaa")}, function(err, cursor) {
   cursor.toArray(function(err, items) {
   test.assertEquals(1, items.length);
   // Let's close the db
   p_client.close();
   });
   });
   });
   });
   });
   });
   Callback hell
   gist.github.com/1309020
   

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10. EventMachine
    github.com/eventmachine/eventmachine
    

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11. "Realtime" applications
    Proxy servers
    Web APIs
    What would you use it for?
    

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12. Goliath
    github.com/postrank-labs/goliath
    

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13. Rack API
    Middleware support
    Ruby fibers
    No callback hell
    1.9.2, jruby, rubinius
    

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14. Fight!
    

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15. Hello world
    github.com/andrew/helloworlds
    

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16. Rack Example
    class HelloWorld
    def call(env)
    [200, {'Content-Type' => 'text/html'}, ["Hello Rack"]]
    end
    end
    run HelloWorld.new
    

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17. Node.js Example
    var http = require('http');
    http.createServer(function (req, res) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('Hello Node\n');
    }).listen(9292, "127.0.0.1");
    console.log('Server running at http://127.0.0.1:9292/');
    

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18. EventMachine Example
    require 'rubygems'
    require 'eventmachine'
    require 'evma_httpserver'
    class HelloWorld < EM::Connection
    include EM::HttpServer
    def post_init
    super
    no_environment_strings
    end
    def process_http_request
    response = EM::DelegatedHttpResponse.new(self)
    response.status = 200
    response.content_type 'text/html'
    response.content = 'Hello EventMachine'
    response.send_response
    end
    end
    EM.run{
    EM.start_server '0.0.0.0', 9292, HelloWorld
    }
    

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19. Goliath Example
    require 'rubygems'
    require 'goliath'
    class Proxy < Goliath::API
    def response(env)
    [200, {}, "Hello Goliath"]
    end
    end
    

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20. Rack Example
    class HelloWorld
    def call(env)
    [200, {'Content-Type' => 'text/html'}, ["Hello Rack"]]
    end
    end
    run HelloWorld.new
    require 'rubygems'
    require 'goliath'
    class Proxy < Goliath::API
    def response(env)
    [200, {}, "Hello Goliath"]
    end
    end
    

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21. rack => 423
    goliath => 2125
    node => 6084
    em => 8814
    Performance (requests/s)
    ab -n 1000 -c 100 http://localhost:9000/
    

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22. URL Shortener
    

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23. var http = require('http'),
    connect = require('connect'),
    redis = require("redis"),
    client = redis.createClient(),
    b62 = require('base62');
    var server = connect.createServer(connect.query());
    server.use('/',
    connect.router(function(app){
    app.get('/', function(req, res, next){
    res.writeHead(200, {'Content-Type': 'text/html'});
    if (req.query.url){
    client.keys('*',function(err, result){
    key = b62.encode(result.length)
    client.set(key, req.query.url, function(err, result){
    res.write('http://localhost:9000/'+key)
    res.end()
    });
    });
    } else {
    res.write('Hi')
    res.end()
    }
    });
    app.get('/:key', function(req, res, next){
    client.get(req.params.key, function(err, result){
    res.writeHead(302, {'Location': result});
    res.end()
    });
    });
    })
    );
    server.listen(9000);
    console.log('Server running at http://127.0.0.1:9000/');
    Node Example
    github.com/andrew/node-shortener
    

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24. class Shortener < EM::Connection
    include EM::HttpServer
    attr_reader :http_request_uri, :http_query_string
    def post_init
    super
    no_environment_strings
    end
    def process_http_request
    redis = EM::Protocols::Redis.connect
    path = @http_request_uri.to_s
    query = @http_query_string.to_s
    response = EM::DelegatedHttpResponse.new(self)
    case path
    when '/'
    if @http_query_string
    params = URI.decode_www_form(query)
    url = params.assoc('url').last.chomp
    redis.keys '*' do |result|
    key = result.size.base62_encode
    redis.set key, url do |result|
    response.status = 200
    response.content_type 'text/html'
    response.content = "http://localhost:9000/#{key}"
    response.send_response
    end
    end
    else
    response.status = 200
    response.content_type 'text/html'
    response.content = 'Hi'
    response.send_response
    end
    else
    redis.get path[1..-1] do |result|
    response.status = 302
    response.headers["Location"] = result
    response.send_response
    end
    end
    end
    end
    EM.run{
    EM.start_server '0.0.0.0', 9000, Shortener
    }
    EM Example
    github.com/andrew/em-shortener
    

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25. REDIS = EventMachine::Synchrony::ConnectionPool.new(:size => 5) do
    Redis.connect
    end
    class Redirect < Goliath::API
    use Goliath::Rack::Params
    def response(env)
    url = REDIS.get params[:key]
    if url
    [302, {:location => url}, nil]
    else
    [404, {}, 'Not Found']
    end
    end
    end
    class Create < Goliath::API
    use Goliath::Rack::Params
    def response(env)
    if params['url']
    key = REDIS.keys.size.base62_encode
    REDIS.set(key, params['url'])
    [200, {}, "http://#{env['HTTP_HOST']}/#{key}"]
    else
    [200, {}, "Hi!"]
    end
    end
    end
    class Shortener < Goliath::API
    map "/" do
    run Create.new
    end
    map "/:key" do
    run Redirect.new
    end
    end
    Goliath Example
    github.com/andrew/goliath-shortener
    

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26. goliath => 1048
    node => 3660
    em => 7943
    Performance (requests/s)
    ab -n 1000 -c 100 http://localhost:9000/2W
    

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27. Things to consider
    

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28. Testing
    

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29. vowsjs.org
    github.com/tmm1/em-spec
    Node
    EM
    

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30. DSLs
    

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31. Sinatra
    get '/hi' do
    "Hello World!"
    end
    sinatrarb.com
    

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32. Express.js
    app.get('/', function(req, res){
    res.send('Hello World');
    });
    expressjs.com
    app.get "/", (req, res) ->
    res.send "Hello World"
    

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33. class HomeAction < Cramp::Action
    def start
    render "Hello World"
    finish
    end
    end
    Cramp
    cramp.in
    

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34. Libraries
    

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35. Deployment
    

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36. Coffeescript
    jashkenas.github.com/coffee-script
    

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37. var http = require('http'),
    connect = require('connect'),
    redis = require("redis"),
    client = redis.createClient(),
    b62 = require('base62');
    var server = connect.createServer(connect.query());
    server.use('/',
    connect.router(function(app){
    app.get('/', function(req, res, next){
    res.writeHead(200, {'Content-Type': 'text/html'});
    if (req.query.url){
    client.keys('*',function(err, result){
    key = b62.encode(result.length)
    client.set(key, req.query.url, function(err, result){
    res.write('http://localhost:9000/'+key)
    res.end()
    });
    });
    } else {
    res.write('Hi')
    res.end()
    }
    });
    app.get('/:key', function(req, res, next){
    client.get(req.params.key, function(err, result){
    res.writeHead(302, {'Location': result});
    res.end()
    });
    });
    })
    );
    server.listen(9000);
    console.log('Server running at http://127.0.0.1:9000/');
    Node Example
    github.com/andrew/node-shortener
    

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38. http = require("http")
    connect = require("connect")
    redis = require("redis")
    client = redis.createClient()
    b62 = require("base62")
    server = connect.createServer(connect.query())
    server.use "/", connect.router((app) ->
    app.get "/", (req, res, next) ->
    res.writeHead 200,
    "Content-Type": "text/html"
    if req.query.url
    client.keys "*", (err, result) ->
    key = b62.encode(result.length)
    client.set key, req.query.url, (err, result) ->
    res.write "http://localhost:9000/" + key
    res.end()
    else
    res.write "Hi"
    res.end()
    app.get "/:key", (req, res, next) ->
    client.get req.params.key, (err, result) ->
    res.writeHead 302,
    Location: result
    res.end()
    )
    server.listen 9000
    console.log "Server running at http://127.0.0.1:9000/"
    Coffeescript Example
    

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39. Rails
    

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40. async-rails
    github.com/igrigorik/async-rails
    

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41. Conclusion
    

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42. Node
    Pros
    Shared code between client and server
    Vibrant Community
    Lightning Fast
    Cons
    Javascript
    Callback hell
    Less mature
    

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43. EventMachine
    Pros
    It’s ruby!
    Mature
    Clever DSLs
    Also fast
    Cons
    More difficult to write than normal ruby
    Restricted to EM libraries
    Not the new hotness
    

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44. Is
    EventMachine
    a worthy alternative to
    Node.js
    

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45. Yes
    

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46. Node or EM are not a
    magic bullets
    

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47. Go - http://golang.org/
    Erlang - http://erlang.org/
    Twisted - http://twistedmatrix.com
    Other languages
    

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48. Fin.
    speakerdeck.com/u/andrew/p/em-vs-node
    

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