Tom Hughes-Croucher - Up and Running with Node.js

Learn how to build high performance Internet and web applications with Node.js. In is session Tom Hughes-Croucher will demonstrate how to quickly build a high performance chat server using Node.js. This live coding exercise will provide a real insight into what it looks like to build a project in server-side Javascript. We will also cover how to deploy Node applications in production and look at just how far Node can really scale… A million connections and beyond?

Transcript

1. A language for the Internet Why JavaScript and Node.js is right for Internet Applications Tom Hughes-Croucher @sh1mmer
2. Me (@sh1mmer)
4. Scalable Server-Side Code with JavaScript Tom Hughes-Croucher Node Up and Running
5. Internet?
8. She’s called Eleanor
14. More features More users More devices More data
15. Stuff Cost
16. How do we cope with the increase in demand?
17. Internet Applications
18. How about search?
19. Browser Spidering Server Web Sites
20. Would take forever!
21. Browser Front-end Server Database Computation
22. Client → Server Computation Batch Computing
24. Client → Server Server → DB Computation Computation Internet Computing
25. “Traditional” Approach
27. Server
28. Request
31. FULL
32. Event-driven Approach
33. Request Place- holder
35. Shared Work Resources
36. Welcome to Node.js
37. Node.js? • Server Side JavaScript runtime • Built on top of V8 JavaScript engine from Google Chrome • Non-blocking I/O APIs • Easy to extend APIs and modules
38. $Enki:~ $ node
39. $Enki:~ $ node > 3 > 2 > 1 false > true == 1 true > true === 1 false
40. > console.log('Hello World'); Hello World > .help .clear Break, and also clear the local context. .exit Exit the prompt .help Show repl options > .clear Clearing context... > .exit Enki:~ $
41. Enki:~ $ node > var foo = "bar"; > foo; 'bar' > .clear Clearing context... > foo ReferenceError: foo is not defined at [object Context]:1:1 at Interface.<anonymous> (repl:98:19) at Interface.emit (events:27:15) at Interface._ttyWrite (readline:295:12) at Interface.write (readline:132:30) at Stream.<anonymous> (repl:79:9) at Stream.emit (events:27:15) at IOWatcher.callback (net:489:16)
42. var http = require('http'); http.createServer(function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }).listen(8124, "127.0.0.1"); console.log('Server running at http://127.0.0.1:8124/');
43. var http = require('http'); //include the http library
44. http.createServer(function (req, res) { }).listen(8124, "127.0.0.1"); //create an http server //when ‘stuff’ happens call this anonymous function //listen on port 8124 of the IP 127.0.0.1
45. http.createServer(function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }) //when ‘stuff’ happens my function fires //I get a request object and a response object //I write to the response object header //HTTP status 200 and content-type ‘text/plain’ //close the response with the body: //Hello World
46. console.log('Server running at http://127.0.0.1:8124/'); //write Server is running at http://127.0.0.1:8124/ //to the console
47. Why is Node.js suited to Internet Apps?
49. What is the event loop?
51. Multi-tasking, one thing at a time.
54. var http = require('http'); server = http.createServer(); server.on('request', function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }); server.listen(8124, "127.0.0.1"); console.log('Server running at http://127.0.0.1:8124/');
55. var http = require('http'); server = http.createServer(); server.on('request', function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }); server.listen(8124, "127.0.0.1"); console.log('Server running at http://127.0.0.1:8124/'); Step 1. Evaluate 'Main'
56. var http = require('http'); server = http.createServer(); server.on('request', function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }); server.listen(8124, "127.0.0.1"); console.log('Server running at http://127.0.0.1:8124/'); Step 1. variables: http -> http module server -> http server listeners: server.request -> function
57. var http = require('http'); server = http.createServer(); server.on('request', function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }); server.listen(8124, "127.0.0.1"); console.log('Server running at http://127.0.0.1:8124/'); Step 2. Event Loop *
58. var http = require('http'); server = http.createServer(); server.on('request', function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }); server.listen(8124, "127.0.0.1"); console.log('Server running at http://127.0.0.1:8124/'); Step 2. Do we have active listeners? listeners: server.request -> function Yes! Wait for listeners. *
59. var http = require('http'); server = http.createServer(); server.on('request', function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }); server.listen(8124, "127.0.0.1"); console.log('Server running at http://127.0.0.1:8124/'); Step 3. Event Calls
60. var http = require('http'); server = http.createServer(); server.on('request', function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }); server.listen(8124, "127.0.0.1"); console.log('Server running at http://127.0.0.1:8124/'); Step 3. 'request' is called. Since listeners: server.request -> function Call function
61. var http = require('http'); server = http.createServer(); server.on('request', function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }); server.listen(8124, "127.0.0.1"); console.log('Server running at http://127.0.0.1:8124/'); Step 3. Loop! (go to Step 2.)
62. Why non-blocking matters
63. Event Loop vs. Threads
64. //node.js style JavaScript query = mysql.query('SELECT * FROM data'); query.on(‘result’, function(result) { for(var i=0;i<length;i++) { var row = result.rows[i]; //do something with the row } });
65. //threaded style JavaScript result = mysql.query('SELECT * FROM data'); for(var i=0;i<length;i++) { var row = result.rows[i]; //do something with the row }
66. var x = "I am a string" ~1ns Running 1 instruction 2ns Data from l1 cpu cache 5ns Data from l2 cpu cache 80ns Data from ram
67. Server mySQL query result
68. result = mysql.query('SELECT * FROM data'); ~100ms Time to run a query in database 50ms Time to roundtrip query over the network
69. Local variable
71. Remote operation
73. Cat 100 Blue Whales
74. Blocking is as bad as stopping
75. Threading wastes memory for a long time because of programming style
76. 2mb PHP 8gb ram 8000/2 = 4000 ~4000 users per machine
77. 8gb ram 8000/0.006 = 1.3m 1.3m/2 ~ 650k users Node.js TCP = 2kb HTTP = 6kb
78. Apache vs NGINX concurrency × reqs/sec http://blog.webfaction.com/a-little-holiday-present
79. Apache vs NGINX concurrency × memory http://blog.webfaction.com/a-little-holiday-present
80. Node.js is designed for communication, just like your applications
81. Demo
82. Thanks!
83. Follow me @sh1mmer Tom Hughes-Croucher @sh1mmer