Designing the code of a large application in production and scaling up to thousands of users while doing it all in Node.js is a challenge that no developer should face alone. I will discuss how we have developed a highly decoupled, plugin-based architecture and a decentralized infrastructure for Cloud9 IDE, along with the technologies we've developed and the difficulties we faced in order to build the largest Node.js application that exists in production.

1. BIG
application
design
Saturday, November 10, 12

2. @sergimansilla
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3. http://c9.io
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4. Smart code completion
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5. Static analysis
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6. Free linux VM
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7. Bring your own machine
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8. Real terminal
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9. Hundreds of thousands
of lines of JavaScript
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10. dynamic,
weakly-typed
language
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11. one single thread
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12. Openshift
Cloud9 datacenter
Remote
VM
Remote
IDE server
VM
Remote
VM
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13. Saturday, November 10, 12

14. Saturday, November 10, 12

15. Modularization
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16. Black box coding
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17. Saturday, November 10, 12

18. re
requi
Good at
abstracting away
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19. re
requi
Not that good at
app-level abstraction
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20. re
requi
Relies on FS
duplicated modules
maps to folder names
hard to configure module
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21. Dependency error handling
coding time compile time run time
!
OM
- BO
KA
- Server crash
- Unhappy customers
- Developer gets fired
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22. How to fix it?
Static dependency list Resolve at startup
Named services No FS required
Easy configuration Pass an object
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23. Architect
github.com/c9/architect
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24. Architect
Everything is a plugin
Plugins can consume plugins
An application is just a set of
plugins
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25. Dependency model
require runtime
Architect compile time
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26. Dependency error handling
Architect
coding time compile time run time
- Happy customers
- Fails before release - Developer keeps job
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27. github.com/sergi/nodejsconfit2012
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28. Saturday, November 10, 12

29. Declare entity ‘cook’ with behavior
Use ‘cook’ to do some cooking
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30. Dependency model
Cooking
Cook
action
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31. package.json
Builds dependency tree
without
executing code
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32. cook/package.json
{
do-­‐cooking/package.json
{
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33. Next
Wrap in Architect plugin code
Extract the code
Make two plugins
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34. Function
signature
Call when
done
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35. Architect plugin code
Module.exports
Options - we’ll talk about it later
Imports - everything you ‘consume’
Register - call when done
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36. Saturday, November 10, 12

37. Saturday, November 10, 12

38. Easy to test
Mock dependencies
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39. ‘cook’ should be called 8 times
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40. No black magic
Specify dependency model
Feed architect a config file
Call ‘createApp’
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41. Saturday, November 10, 12

42. Saturday, November 10, 12

43. Configuration
Per-plugin options
No global options object
Specify in config file
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44. Saturday, November 10, 12

45. Saturday, November 10, 12

46. Options
Passed in at startup
Options can be dependencies
Fail if options aren’t present
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47. Saturday, November 10, 12

48. Saturday, November 10, 12

49. Your app as
chunks of functionality
rather than sets of classes
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50. chunks of functionality
Implicit type constraints
Keep implementation private
Swap features instead of interfaces
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51. How does Cloud9 use it?
Open source version
Local version (OS + sync)
Hosted version
Normal
FTP
SSH
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52. Saturday, November 10, 12

53. Swap feature per
implementation
On OSS: talk local filesystem
On FTP: talk FTP library
On SSH: talk via a SSH bridge
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54. Architect is a DI
framework
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55. But a quite
special one
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56. Single node.js process
IDE instance IDE instance
(FTP) (SSH)
Other code
(dashboard etc.)
IDE instance IDE instance
(Normal) (Normal)
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57. Architect can do
Multiple instances of same plugin
Run independently
But in the same process
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58. Centralized event bus
Loose coupling between plugins
No hard dependencies!
Can also do inter-context communication
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59. React on event
Other plugin
Event
bus
Emit event
Plugin
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60. Saturday, November 10, 12

61. Saturday, November 10, 12

62. And now scale
Swap it with i.e. Redis PubSub
Plugins will never notice
Modular awesomeness!
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63. Modularize in feature blocks
Don’t over engineer
Don’t create too small blocks
They aren’t interfaces!
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64. Avoid context switching
Less code!
Less errors!
Less boilerplate!
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65. Loose coupling
Use (don’t abuse) an event bus
Smaller dependency graph
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66. github.com/c9/architect
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67. Happy coding!
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68. http://c9.io
@sergimansilla
github.com/sergi
Saturday, November 10, 12