Architecting large node.js applications

Sergi Mansilla introduces one of the main components to hold Cloud9's architecture together: Architect.

Transcript

1. large
   Architecting
   node.js
   applications
   Monday, October 22, 12
   

   View Slide

2. @sergimansilla
   Monday, October 22, 12
   

   View Slide

3. Program
   ☐ Cloud9 IDE?
   ☐ Growing pains
   ☐ Introducing Architect
   ☐ Lessons learned
   Monday, October 22, 12
   

   View Slide

4. Normal developers
   Monday, October 22, 12
   

   View Slide

5. JavaScript Developer
   Monday, October 22, 12
   

   View Slide

6. Cloud9 IDE - http://c9.io
   Monday, October 22, 12
   

   View Slide

7. debugging
   Real
   Monday, October 22, 12
   

   View Slide

8. (Smart!)
   Code completion
   Monday, October 22, 12
   

   View Slide

9. analysis
   Static
   Monday, October 22, 12
   

   View Slide

10. Free
    Linux
    VM
    Monday, October 22, 12
    

    View Slide

11. Bring your own machine
    Monday, October 22, 12
    

    View Slide

12. Real terminal
    Monday, October 22, 12
    

    View Slide

13. Collaboration
    Monday, October 22, 12
    

    View Slide

14. See each other type
    Debug together
    Productivity++
    Monday, October 22, 12
    

    View Slide

15. Create
    Share Test
    Deploy Run/Debug
    Monday, October 22, 12
    

    View Slide

16. Program
    ☑ Cloud9 IDE?
    ☐ Growing pains
    ☐ Introducing Architect
    ☐ Lessons learned
    Monday, October 22, 12
    

    View Slide

17. 10,000s
    of JavaScript
    LOC
    Monday, October 22, 12
    

    View Slide

18. dynamic,
    typed
    weakly
    language
    Monday, October 22, 12
    

    View Slide

19. one
    thread
    single
    Monday, October 22, 12
    

    View Slide

20. Remote VM
    Cloud9 datacenter
    IDE server Remote VM
    Remote VM
    Openshift
    Monday, October 22, 12
    

    View Slide

21. Pure madness
    Monday, October 22, 12
    

    View Slide

22. Modularization
    Monday, October 22, 12
    

    View Slide

23. Black
    box
    coding
    Monday, October 22, 12
    

    View Slide

24. Monday, October 22, 12
    

    View Slide

25. Java/.NET
    Node.js
    import(s)
    require
    Monday, October 22, 12
    

    View Slide

26. abstracting
    away
    Great for
    require
    Monday, October 22, 12
    

    View Slide

27. application
    modularity
    Not Great for
    require
    Monday, October 22, 12
    

    View Slide

28. duplicated modules
    maps to folder names
    Relies on FS
    require
    Hard to configure module
    Monday, October 22, 12
    

    View Slide

29. Dependency error handling
    coding time compile time run time
    KA-BOOM!
    - Server crash
    - Unhappy customers
    - Developer gets fired
    Monday, October 22, 12
    

    View Slide

30. How to fix it?
    Static dependency list
    Named services
    Easy configuration
    Resolve at startup
    No FS required
    Pass an object
    Monday, October 22, 12
    

    View Slide

31. Program
    ☑ Cloud9 IDE?
    ☑ Growing pains
    ☐ Introducing Architect
    ☐ Lessons learned
    Monday, October 22, 12
    

    View Slide

32. Architect
    github.com/c9/architect
    Monday, October 22, 12
    

    View Slide

33. Architect
    Everything is a plugin
    Plugins can consume plugins
    An application is just a set of plugins
    Monday, October 22, 12
    

    View Slide

34. Dependency model
    require
    Architect
    runtime
    compile time
    Monday, October 22, 12
    

    View Slide

35. Dependency error handling
    Architect
    coding time compile time run time
    - Happy customers
    - Developer keeps job
    - Fails before release
    Monday, October 22, 12
    

    View Slide

36. Monday, October 22, 12
    

    View Slide

37. Declare entity ‘presenter’ with behavior
    Use ‘presenter’ to do a presentation
    Monday, October 22, 12
    

    View Slide

38. Presenter Presentation
    Dependency model
    Monday, October 22, 12
    

    View Slide

39. Express our model
    package.json
    Builds dependency tree
    executing code
    without
    Monday, October 22, 12
    

    View Slide

40. Monday, October 22, 12
    

    View Slide

41. What’s next?
    Extract the code
    Wrap in Architect plugin code
    Make two plugins
    Monday, October 22, 12
    

    View Slide

42. Function
    signature
    Call when done
    Monday, October 22, 12
    

    View Slide

43. Architect plugin code
    Module.exports
    Options - we’ll get to that
    Imports - everything you ‘consume’
    Register - invoke when done
    Monday, October 22, 12
    

    View Slide

44. Monday, October 22, 12
    

    View Slide

45. Monday, October 22, 12
    

    View Slide

46. Easy to test
    Mock dependencies
    Monday, October 22, 12
    

    View Slide

47. Assert ‘dance’ is called 11 times
    Monday, October 22, 12
    

    View Slide

48. No black magic
    Specify dependency model
    Feed architect a config file
    Call ‘createApp’
    Monday, October 22, 12
    

    View Slide

49. Monday, October 22, 12
    

    View Slide

50. Monday, October 22, 12
    

    View Slide

51. Configuration
    Per-plugin options
    No global options object
    Specify in config file
    Monday, October 22, 12
    

    View Slide

52. Monday, October 22, 12
    

    View Slide

53. Monday, October 22, 12
    

    View Slide

54. Options
    Automatically passed in at startup
    Options are also dependencies
    Fail if options aren’t present
    Monday, October 22, 12
    

    View Slide

55. Monday, October 22, 12
    

    View Slide

56. Monday, October 22, 12
    

    View Slide

57. Architect makes you think of your app as
    chunks of functionality
    rather than sets of classes
    Monday, October 22, 12
    

    View Slide

58. Think ‘chunks of functionality’
    Implicit type constraints
    Keep implementation private
    Swap features instead of interfaces
    Monday, October 22, 12
    

    View Slide

59. How does Cloud9 use it?
    Open source version
    Local version (OS + sync)
    Hosted version
    Normal
    FTP
    SSH
    Monday, October 22, 12
    

    View Slide

60. Monday, October 22, 12
    

    View Slide

61. Swap feature per
    implementation
    On Open source: talk local filesystem
    On FTP: talk FTP library
    On SSH: talk via a SSH bridge
    Monday, October 22, 12
    

    View Slide

62. Here is something your
    DI framework can’t do
    Monday, October 22, 12
    

    View Slide

63. IDE instance
    (FTP)
    IDE instance
    (SSH)
    IDE instance
    (Normal)
    IDE instance
    (Normal)
    Single node.js process
    Other code
    (dashboard etc.)
    Monday, October 22, 12
    

    View Slide

64. Monday, October 22, 12
    

    View Slide

65. Architect can do
    Multiple instances of same plugin
    Run independently
    But in the same process
    Monday, October 22, 12
    

    View Slide

66. Monday, October 22, 12
    

    View Slide

67. Monday, October 22, 12
    

    View Slide

68. HERE’S SOMETHING COOL
    Monday, October 22, 12
    

    View Slide

69. Centralized eventbus
    Loose coupling between plugins
    No hard dependencies!
    Can also do inter-context communication
    Monday, October 22, 12
    

    View Slide

70. Event
    bus
    Plugin
    Other plugin
    Emit event
    React on event
    Monday, October 22, 12
    

    View Slide

71. Monday, October 22, 12
    

    View Slide

72. Monday, October 22, 12
    

    View Slide

73. And now scale up
    Need something inter-server
    Swap it with i.e. Redis PubSub
    Plugins will never notice
    Modular awesomeness!
    Monday, October 22, 12
    

    View Slide

74. Program
    ☑ Cloud9 IDE?
    ☑ Growing pains
    ☑ Introducing Architect
    ☐ Lessons learned
    Monday, October 22, 12
    

    View Slide

75. Modularize in feature blocks
    Don’t over engineer
    Don’t create too small blocks
    They aren’t interfaces!
    Monday, October 22, 12
    

    View Slide

76. Use dependency injection
    Architect (JavaScript)
    StructureMap (.NET)
    Spring (Java)
    Monday, October 22, 12
    

    View Slide

77. Avoid context switching
    Less code!
    Less errors!
    Less boilerplate!
    Monday, October 22, 12
    

    View Slide

78. Loose coupling
    Use an event bus
    Smaller dependency graph
    Monday, October 22, 12
    

    View Slide

79. github.com/c9/architect
    Monday, October 22, 12
    

    View Slide

80. Happy coding!
    Monday, October 22, 12
    

    View Slide

81. Sergi Mansilla
    @sergimansilla
    github.com/sergi
    http://c9.io
    Monday, October 22, 12
    

    View Slide