EM vs Node

1. Is EventMachine a worthy alternative to Node.js
2. Andrew Nesbitt github.com/andrew @teabass
3. forwardtechnology.co.uk
4. Node.js nodejs.org
5. "Evented I/O for V8 JavaScript" Concurrent, scalable network programs Speaks HTTP natively Asynchronous, non-blocking by design
6. "Realtime" applications Proxy servers Web APIs What would you use it for?
7. Synchronous I/O
8. Asynchronous I/O
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
10. EventMachine github.com/eventmachine/eventmachine
11. "Realtime" applications Proxy servers Web APIs What would you use it for?
12. Goliath github.com/postrank-labs/goliath
13. Rack API Middleware support Ruby fibers No callback hell 1.9.2, jruby, rubinius
14. Fight!
15. Hello world github.com/andrew/helloworlds
16. Rack Example class HelloWorld def call(env) [200, {'Content-Type' => 'text/html'}, ["Hello Rack"]] end end run HelloWorld.new
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/');
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 }
19. Goliath Example require 'rubygems' require 'goliath' class Proxy < Goliath::API def response(env) [200, {}, "Hello Goliath"] end end
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
21. rack => 423 goliath => 2125 node => 6084 em => 8814 Performance (requests/s) ab -n 1000 -c 100 http://localhost:9000/
22. URL Shortener
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
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
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
26. goliath => 1048 node => 3660 em => 7943 Performance (requests/s) ab -n 1000 -c 100 http://localhost:9000/2W
27. Things to consider
28. Testing
29. vowsjs.org github.com/tmm1/em-spec Node EM
30. DSLs
31. Sinatra get '/hi' do "Hello World!" end sinatrarb.com
32. Express.js app.get('/', function(req, res){ res.send('Hello World'); }); expressjs.com app.get "/", (req, res) -> res.send "Hello World"
33. class HomeAction < Cramp::Action def start render "Hello World" finish end end Cramp cramp.in
34. Libraries
35. Deployment
36. Coffeescript jashkenas.github.com/coffee-script
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
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
39. Rails
40. async-rails github.com/igrigorik/async-rails
41. Conclusion
42. Node Pros Shared code between client and server Vibrant Community Lightning Fast Cons Javascript Callback hell Less mature
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
44. Is EventMachine a worthy alternative to Node.js
45. Yes
46. Node or EM are not a magic bullets
47. Go - http://golang.org/ Erlang - http://erlang.org/ Twisted - http://twistedmatrix.com Other languages
48. Fin. speakerdeck.com/u/andrew/p/em-vs-node