The document discusses Node.js and compares it to other technologies like CakePHP. It provides an overview of Node.js including its event-driven and asynchronous model, key features like the V8 engine and packages/modules, and frameworks like Express. It then demonstrates building a sample messaging application with a JSON API using both CakePHP and Node.js.

1. Going crazy with Node.js and CakePHP CakeFest 2011 Manchester, UK Mariano Iglesias @mgiglesias

2. Hello world! Hailing from Miramar, Argentina CakePHP developer since 2006 Worked in countless projects Contact me if you are looking for work gigs! A FOSS supporter, and contributor CakePHP 1.3 book recently published Survived Node Knockout 2011

3. Node.js... that's not CakePHP! If there's something I'd like you to learn it'd be... There are different solutions to different problems! CakePHP Python Node.js C++ NGINx / Lighttpd

4. What's the problem? What's an app normally doing? What can I do then? Add caching Add workers Faster DB Vertical scale: add more resources Horizontal scale: add more servers Still can't get n10K concurrent users?

5. Threads vs events http://blog.wefaction.com/a-little-holiday-present

6. What is Node.js? In a nutshell, it's JavaScript on the server V8 JavaScript engine Evented I/O + =

7. V8 Engine Property access through hidden classes Machine code Garbage collection Performance is king http://code.google.com/apis/v8/design.html

8. Evented I/O libeio : async I/O libev : event loop libuv : wrapper for libev and IOCP db. query (). select ( '*' ). from ( 'users' ). execute ( function () { fs. readFile ( 'settings.json' , function () { // ... }); });

9. Libuv == Node.exe http_simple (/bytes/1024) over 1-gbit network, with 700 concurrent connections: windows-0.5.4 : 3869 r/s windows-latest : 4990 r/s linux-latest-legacy : 5215 r/s linux-latest-uv : 4970 r/s

10. More stuff buffer : large portions of data c-ares : async DNS child_process : spawn(), exec(), fork() (0.5.x) crypto : OpenSSL http_parser : high performance HTTP parser timer : setTimeout(), setInterval()

11. Should I throw away CakePHP? Remember... There are different solutions to different problems!

12. First node.js server var http = require ( 'http' ); http. createServer ( function (req, res) { res. writeHead ( 200 , { 'Content-type' : 'text/plain' }); res. end ( 'Hello world!' ); }). listen ( 1337 ); console. log ( 'Server running at http://localhost:1337' );

13. Understanding the event loop There is a single thread running in Node.js No parallel execution... for YOUR code var http = require ( 'http' ); http. createServer ( function (req, res) { console. log ( 'New request' ); // Block for five seconds var now = new Date (). getTime (); while ( new Date (). getTime () < now + 5000 ) ; // Response res. writeHead ( 200 , { 'Content-type' : 'text/plain' }); res. end ( 'Hello world!' ); }). listen ( 1337 ); console. log ( 'Server running at http://localhost:1337' );

14. What about multiple cores? The load balancer approach :1337 :1338 :1339 The OS approach var http = require ( 'http' ), cluster = ...; var server = http. createServer ( function (req, res) { res. writeHead ( 200 , { 'Content-type' : 'text/plain' }); res. end ( 'Hello world!' ); }); cluster (server). listen ( 1337 );

15. Packaged modules $ curl http://npmjs.org/install.sh | sh $ npm install db-mysql There are more than 3350 packages, and more than 14 are added each day

16. Packaged modules var m = require ( './module' ); m. sum ( 1 , 3 , function (err, res) { if (err) { return console. log ( 'ERROR: ' + err); } console. log ( 'RESULT IS: ' + res); }); exports.sum = function (a, b, callback) { if ( isNaN (a) || isNaN (b)) { return callback ( new Error ( 'Invalid parameter' )); } callback ( null , a+b); };

17. Frameworks are everywhere Multiple environments Middleware Routing View rendering Session support http://expressjs.com

18. Multiple environments var express = require ( 'express' ); var app = express. createServer (); app. get ( '/' , function (req, res) { res. send ( 'Hello world!' ); }); app. listen ( 3000 ); console. log ( 'Server listening in http://localhost:3000' ); app. configure ( function () { app. use (express. bodyParser ()); }); app. configure ( 'dev' , function () { app. use (express. logger ()); }); $ NODE_ENV=dev node app.js

19. Middleware function getUser (req, res, next) { if (!req.params.id) { return next (); } else if (!users[req.params.id]) { return next ( new Error ( 'Invalid user' )); } req.user = users[req.params.id]; next (); } app. get ( '/users/:id?' , getUser, function (req, res, next) { if (!req.user) { return next (); } res. send (req.user); });

20. View rendering views/index.jade app. configure ( function () { app. set ( 'views' , __dirname + '/views' ); app. set ( 'view engine' , 'jade' ); }); app. get ( '/users/:id?' , function (req, res, next) { if (!req.params.id) { return next (); } if (!users[req.params.id]) { return next ( new Error ( 'Invalid user' )); } res. send (users[req.params.id]); }); app. get ( '/users' , function (req, res) { res. render ( 'index' , { layout: false , locals: { users: users } }); }); html body h1 Node.js ROCKS ul - each user, id in users li a(href='/users/#{id}') #{user.name}

21. node-db What's the point? Supported databases Queries Manual API JSON types Buffer http://nodejsdb.org

22. node-db var mysql = require ( 'db-mysql' ); new mysql. Database ({ hostname: 'localhost' , user: 'root' , password: 'password' , database: 'db' }). connect ( function (err) { if (err) { return console. log ( 'CONNECT error: ' , err); } this . query (). select ([ 'id' , 'email' ]). from ( 'users' ). where ( 'approved = ? AND role IN ?' , [ true , [ 'user' , 'admin' ] ]). execute ( function (err, rows, cols) { if (err) { return console. log ( 'QUERY error: ' , err); } console. log (rows, cols); }); });

23. Let's get to work

24. Sample application Basic CakePHP 2.0 app JSON endpoint for latest messages

25. Why are we doing this? CakePHP: 442.90 trans/sec Node.js: 610.09 trans/sec Node.js & Pool: 727.19 trans/sec Node.js & Pool & Cluster: 846.61 trans/sec $ siege -d1 -r10 -c25

26. Sample application CREATE TABLE `users`( `id` char(36) NOT NULL, `email` varchar(255) NOT NULL, `password` text NOT NULL, `name` varchar(255) NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY `email` (`email`) ); CREATE TABLE `messages` ( `id` char(36) NOT NULL, `from_user_id` char(36) NOT NULL, `to_user_id` char(36) NOT NULL, `message` text NOT NULL, `created` datetime NOT NULL, PRIMARY KEY (`id`), KEY `from_user_id` (`from_user_id`), KEY `to_user_id` (`to_user_id`), CONSTRAINT `messages_from_user` FOREIGN KEY (`from_user_id`) REFERENCES `users` (`id`), CONSTRAINT `messages_to_user` FOREIGN KEY (`to_user_id`) REFERENCES `users` (`id`) );

27. Sample application http://cakefest3.loc/messages/incoming/4e4c2155-e030-477e-985d-18b94c2971a2 [ { &quot;Message&quot;: { &quot;id&quot;:&quot;4e4d8cf1-15e0-4b87-a3fc-62aa4c2971a2&quot;, &quot;message&quot;:&quot;Hello Mariano!&quot; }, &quot;FromUser&quot;: { &quot;id&quot;:&quot;4e4c2996-f964-4192-a084-19dc4c2971a2&quot;, &quot;name&quot;:&quot;Jane Doe&quot; }, &quot;ToUser&quot;: {&quot;name&quot;:&quot;Mariano Iglesias&quot;} }, { &quot;Message&quot;: { &quot;id&quot;:&quot;4e4d8cf5-9534-49b9-8cba-62bf4c2971a2&quot;, &quot;message&quot;:&quot;How are you?&quot; }, &quot;FromUser&quot;: { &quot;id&quot;:&quot;4e4c2996-f964-4192-a084-19dc4c2971a2&quot;, &quot;name&quot;:&quot;Jane Doe&quot; }, &quot;ToUser&quot;: {&quot;name&quot;:&quot;Mariano Iglesias&quot;} } ]

28. CakePHP code class MessagesController extends AppController { public function incoming ( $userId ) { $since = ! empty ( $this ->request->query[ 'since' ]) ? urldecode ( $this ->request->query[ 'since' ]) : null; if ( empty ( $since ) || ! preg_match ( '/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}$/' , $since ) ) { $since = '0000-00-00 00:00:00' ; } $messages = ... $this ->autoRender = false; $this ->response-> type ( 'json' ); $this ->response-> body ( json_encode ( $messages )); $this ->response-> send (); $this -> _stop (); } }

29. CakePHP code $messages = $this ->Message-> find ( 'all' , array ( 'fields' => array ( 'Message.id' , 'Message.message' , 'FromUser.id' , 'FromUser.name' , 'ToUser.name' ), 'joins' => array ( array ( 'type' => 'INNER' , 'table' => 'users' , 'alias' => 'FromUser' , 'conditions' => array ( 'FromUser.id = Message.from_user_id' ) ), array ( 'type' => 'INNER' , 'table' => 'users' , 'alias' => 'ToUser' , 'conditions' => array ( 'ToUser.id = Message.to_user_id' ) ), ), 'conditions' => array ( 'Message.to_user_id' => $userId , 'Message.created >=' => $since ), 'order' => array ( 'Message.created' => 'asc' ), 'recursive' => - 1 ));

30. Node.js code: express var express = require ( 'express' ), mysql = require ( 'db-mysql' ), port = 1337 ; var app = express. createServer (); app. get ( '/messages/incoming/:id' , function (req, res){ var r = ... var userId = req.params.id; if (!userId) { return r ( new Error ( 'No user ID provided' )); } var since = req.query.since ? req.query.since : false ; if (!since || !/^\d{ 4 }-\d{ 2 }-\d{ 2 } \d{ 2 }:\d{ 2 }:\d{ 2 }$/. test (since)) { since = '0000-00-00 00:00:00' ; } new mysql. Database (...). connect ( function (err) { if (err) { return r (err); } ... }); }); app. listen (port); console. log ( 'Server running at http://localhost:' + port);

31. Node.js code: express Avoids the typical: XMLHttpRequest cannot load URL. Origin URL is not allowed by Access-Control-Allow-Origin var r = function (err, data) { if (err) { console. log ( 'ERROR: ' + err); res. writeHead ( 503 ); return res. end (); } res.charset = 'UTF-8' ; res. contentType ( 'application/json' ); res. header ( 'Access-Control-Allow-Origin' , '*' ); res. send (data); };

32. Node.js code: node-db db. query (). select ({ 'Message_id' : 'Message.id' , 'Message_message' : 'Message.message' , 'FromUser_id' : 'FromUser.id' , 'FromUser_name' : 'FromUser.name' , 'ToUser_name' : 'ToUser.name' }). from ({ 'Message' : 'messages' }). join ({ type: 'INNER' , table: 'users' , alias: 'FromUser' , conditions: 'FromUser.id = Message.from_user_id' }). join ({ type: 'INNER' , table: 'users' , alias: 'ToUser' , conditions: 'ToUser.id = Message.to_user_id' }). where ( 'Message.to_user_id = ?' , [ userId ]). and ( 'Message.created >= ?' , [ since ]). order ({ 'Message.created' : 'asc' }). execute ( function (err, rows) { ... });

33. Node.js code: node-db function (err, rows) { db. disconnect (); if (err) { return r (err); } for ( var i= 0 , limiti=rows.length; i < limiti; i++) { var row = {}; for ( var key in rows [i] ) { var p = key. indexOf ( '_' ), model = key. substring ( 0 , p), field = key. substring (p+ 1 ); if (!row [model] ) { row [model] = {}; } row [model][field] = rows [i][key] ; } rows [i] = row; } r ( null , rows); }

34. Long polling Reduce HTTP requests Open one request and wait for response function fetch () { $. ajax ({ url: ..., async: true , cache: false , timeout: 60 * 1000 , success: function (data) { ... setTimeout ( fetch (), 1000 ); }, error: ... }); }

35. Bonus tracks

36. #1 Pooling connections

37. Pooling connections https://github.com/coopernurse/node-pool var mysql = require ( 'db-mysql' ), generic_pool = require ( 'generic-pool' ); var pool = generic_pool. Pool ({ name: 'mysql' , max: 30 , create: function (callback) { new mysql. Database ({ ... }). connect ( function (err) { callback (err, this ); }); }, destroy: function (db) { db. disconnect (); } }); pool. acquire ( function (err, db) { if (err) { return r (err); } ... pool. release (db); });

38. #2 Clustering express

39. Clustering express http://learnboost.github.com/cluster var cluster = require ( 'cluster' ), port = 1337 ; cluster ( 'app' ). on ( 'start' , function () { console. log ( 'Server running at http://localhost:' + port); }). on ( 'worker' , function (worker) { console. log ( 'Worker #' + worker.id + ' started' ); }). listen (port); var express = require ( 'express' ), generic_pool = require ( 'generic-pool' ); var pool = generic_pool. Pool ({ ... }); module.exports = express. createServer (); module.exports. get ( '/messages/incoming/:id' , function (req, res) { pool. acquire ( function (err, db) { ... }); });

40. Clustering express

41. #3 Dealing with parallel tasks

42. Dealing with parallel tasks Asynchronous code can get complex to manage Async offers utilities for collections Control flow series (tasks, [callback]) parallel (tasks, [callback]) waterfall (tasks, [callback]) https://github.com/caolan/async

43. Dealing with parallel tasks var async = require ( 'async' ); async. waterfall ([ function (callback) { callback ( null , 4 ); }, function (id, callback) { callback ( null , { id: id, name: 'Jane Doe' }); }, function (user, callback) { console. log ( 'USER: ' , user); callback ( null ); } ]); $ node app.js USER: { id: 4, name: 'Jane Doe' }

44. #4 Unit testing

45. Unit testing Export tests from a module Uses node's assert module: ok (value) equal (value, expected) notEqual (value, expected) throws (block, error) doesNotThrow (block, error) The expect () and done () functions https://github.com/caolan/nodeunit

46. Unit testing var nodeunit = require (' nodeunit' ); exports[ 'group1' ] = nodeunit. testCase ({ setUp: function (cb) { cb (); }, tearDown: function (cb) { cb (); }, test1: function (test) { test. equals ( 1 + 1 , 2 ); test. done (); }, test2: function (test) { test. expect ( 1 ); ( function () { test. equals ( 'a' , 'a' ); })(); test. done (); } }); $ nodeunit tests.js nodeunit.js ✔ group1 – test1 ✔ group1 – test2

47. Questions?

48. Thanks! You rock! @mgiglesias http://marianoiglesias.com.ar