Node.js is an event-driven I/O platform built on Google's V8 JavaScript engine. It allows for non-blocking asynchronous programming which solves problems like slow file uploads, long database transactions, and accessing external web resources. It uses an event loop model with callbacks instead of blocking I/O. Popular frameworks that build on Node.js include Connect and Express. While Node.js has advantages like small memory footprint and fast performance, challenges include maintaining large applications with chained callbacks. Future possibilities include coroutines for true concurrency similar to languages like Erlang and Haskell.

1. node.js
evented I/O for V8 javascript

2. the Problem

3. the Problem

4. the Problem

5. the Problem

6. the Problem
file uploads

7. the Problem
file uploads
long database transactions

8. the Problem
file uploads
long database transactions
external web resource

9. blocking I/O

10. solutions

11. solutions

12. solutions
worker queues

13. solutions
worker queues
poll for results

14. event-driven I/O

15. event-driven I/O

16. event-driven I/O
nginX + Lua

17. event-driven I/O
nginX + Lua
Twisted (Python)

18. event-driven I/O
nginX + Lua
Twisted (Python)
EventMachine (Ruby)

19. node.js

20. node.js

21. node.js
Google’s V8 engine + async I/O

22. node.js
Google’s V8 engine + async I/O
CommonJS modules

23. demo time

24. simple HTTP server

26. start it

28. simulate wait

30. benchmark

32. HTTP remote fetch

34. HTTP proxy

36. advantages

37. advantages

38. advantages
JS has event-handling built-in

39. advantages
JS has event-handling built-in
clean-room design w/o blocking APIs

40. advantages
JS has event-handling built-in
clean-room design w/o blocking APIs
small memory footprint

41. advantages
JS has event-handling built-in
clean-room design w/o blocking APIs
small memory footprint
fast

42. advantages
JS has event-handling built-in
clean-room design w/o blocking APIs
small memory footprint
fast
shareable code

43. drawbacks

44. drawbacks

45. drawbacks
chained callbacks

46. drawbacks
chained callbacks
larger codebase maybe hard to maintain

47. frameworks

48. frameworks

49. frameworks
connect

50. frameworks
connect
express

51. frameworks
connect
express
persevere

52. what’s next

53. what’s next

54. what’s next
coroutines / continuations

55. what’s next
coroutines / continuations
real concurrency

56. what’s next
coroutines / continuations
real concurrency
Erlang / Haskell

57. questions?