This document discusses using Node.js for networking and making asynchronous DNS requests. Some key advantages of Node.js are its event-driven programming model and speed. It describes building packets and sending them via UDP/TCP sockets. It also covers performing a large-scale reverse DNS lookup project more quickly using an asynchronous approach with Node.js compared to a synchronous Python implementation.

1. NETWORKING WITH NODEJS
Philipp Fehre http://sideshowcoder.com
Inspired by Dirk Haage http://dirk.haage.info/

2. WHY?

4. • Speed

5. • Speed
• Event driven programming

6. • Speed
• Event driven programming
• Javascript

7. • Speed
• Event driven programming
• Javascript
• Because we can!

8. BASICS

10. • Real Simple TCP

11. • Real Simple TCP
• Build a binary packet

12. • Real Simple TCP
• Build a binary packet
• Sent the Packet (UDP/TCP Socket)

13. • Real Simple TCP
• Build a binary packet
• Sent the Packet (UDP/TCP Socket)
• Make DNS Requests

14. TCP SERVER

15. TCP CLIENT

16. DATA

17. ENCODING

18. BUILD PACKET

19. OPEN A SOCKET

20. SENDING

21. EXAMPLE

22. GROWL

23. DOING SOMETHING USEFUL
NOW...

24. RDNS ISTRUKTA PROJECT

25. RDNS ISTRUKTA PROJECT
• Resolve reverse DNS
names

26. RDNS ISTRUKTA PROJECT
• Resolve reverse DNS
names
• Scanthe whole
Internet

27. RDNS ISTRUKTA PROJECT
• Resolve reverse DNS
names
• Scanthe whole
Internet
• 2^32 IPs so better be
fast!

28. MAKE A DNS REQUEST

29. REMINDER HOW DNS WORKS

30. 2^32 REQUEST TO 1 DNS
SERVER?

31. 2^32 REQUEST TO 1 DNS
SERVER?
• Does not work, any sensible server will respond with “meh”

32. 2^32 REQUEST TO 1 DNS
SERVER?
• Does not work, any sensible server will respond with “meh”
• Need to spread request across servers

33. 2^32 REQUEST TO 1 DNS
SERVER?
• Does not work, any sensible server will respond with “meh”
• Need to spread request across servers
• Handle own recursive resolution

34. 2^32 REQUEST TO 1 DNS
SERVER?
• Does not work, any sensible server will respond with “meh”
• Need to spread request across servers
• Handle own recursive resolution
• Need to set DNS Server per request

35. EXPOSING SETTING

36. MAKE A DNS REQUEST VIA A
SPECIFIC SERVER

37. WHY NODE?

38. WHY NODE?
• Requests need to run async

39. WHY NODE?
• Requests need to run async
• The Javascript way to handle evented systems

40. WHY NODE?
• Requests need to run async
• The Javascript way to handle evented systems
• First implementation in Python did not perform well enough...

41. EVENTED ARCHITECTURE

42. 2^32 IP = NEED FOR SPEED

43. 2^32 IP = NEED FOR SPEED
• Sync: Python 4 workers 36000 Requests/min = 82 Days

44. 2^32 IP = NEED FOR SPEED
• Sync: Python 4 workers 36000 Requests/min = 82 Days
• Async: Node 1 process 500000 Requests/min = 5 Days*
* Calculated wrong before sorry it’s not 2.5h

45. DEMO

46. PRO-THOUGHTS

47. PRO-THOUGHTS
• Event driven programming

48. PRO-THOUGHTS
• Event driven programming
• Easily modifiable

49. PRO-THOUGHTS
• Event driven programming
• Easily modifiable
• Node is moving quick

50. PRO-THOUGHTS
• Event driven programming
• Easily modifiable
• Node is moving quick
• Javascript is fun!

51. COUNTER-THOUGHTS

52. COUNTER-THOUGHTS
• API not “there” yet in some cases

53. COUNTER-THOUGHTS
• API not “there” yet in some cases
• Really web focused

54. COUNTER-THOUGHTS
• API not “there” yet in some cases
• Really web focused
• Node is moving to quick (from time to time)!

55. REFERENCES
• Node DNS Patch: https://github.com/sideshowcoder/Add-NodeJS-DNS-Server-Settings
• Growl for Node: https://github.com/sideshowcoder/Nodrrr
• Web: http://sideshowcoder.com Twitter: @ischi
• Pictures courtesy of google image search ;)

56. AD!