1. Reverse Ajax
Something You Don’t Know About HTTP
RDSS Team
2012-04
Monday, May 14, 12

2. Author
澄净
F2E & Translator
http://goddyzhao.me
Monday, May 14, 12

3. About
RDSS
Research on Domain Specific Solution
We focus on existing specification, solution, production etc.
We apply our research to practice.
Monday, May 14, 12

4. Solutions
• HTTP Polling & JSONP Polling
• Piggyback
• Comet
• Bayeux(CometD)
• WebSockets
Monday, May 14, 12

5. HTTP Polling
Browser Server
Timeline
Timeline
Monday, May 14, 12

6. HTTP Polling
Browser Server
Ajax Requst #1
Timeline
Timeline
Monday, May 14, 12

7. HTTP Polling
Browser Server
Ajax Requst #1
Response #1(no data)
Timeline
Timeline
Monday, May 14, 12

8. HTTP Polling
Browser Server
Ajax Requst #1
Response #1(no data)
Timeline
Timeline
Ajax Requst #2
Monday, May 14, 12

9. HTTP Polling
Browser Server
Ajax Requst #1
Response #1(no data)
Timeline
Timeline
Ajax Requst #2
Response #2(no data)
Monday, May 14, 12

10. HTTP Polling
Browser Server
Ajax Requst #1
Response #1(no data)
Timeline
Timeline
Ajax Requst #2
Response #2(no data)
Data/Event
Monday, May 14, 12

11. HTTP Polling
Browser Server
Ajax Requst #1
Response #1(no data)
Timeline
Timeline
Ajax Requst #2
Response #2(no data)
Data/Event
Data/Event
Monday, May 14, 12

12. HTTP Polling
Browser Server
Ajax Requst #1
Response #1(no data)
Timeline
Timeline
Ajax Requst #2
Response #2(no data)
Data/Event
Data/Event
Ajax Requst #3
Monday, May 14, 12

13. HTTP Polling
Browser Server
Ajax Requst #1
Response #1(no data)
Timeline
Timeline
Ajax Requst #2
Response #2(no data)
Data/Event
Data/Event
Ajax Requst #3
Response #3(with data)
Monday, May 14, 12

14. HTTP Polling
Monday, May 14, 12

15. HTTP Polling
Monday, May 14, 12

16. HTTP Polling
Pros
Monday, May 14, 12

17. HTTP Polling
Pros
Require no special features on server
Monday, May 14, 12

18. HTTP Polling
Pros
Require no special features on server
Works in all browsers
Monday, May 14, 12

19. HTTP Polling
Pros
Require no special features on server
Works in all browsers
Easy to implement in client
Monday, May 14, 12

20. HTTP Polling
Pros
Require no special features on server
Works in all browsers
Easy to implement in client
Cons
Monday, May 14, 12

21. HTTP Polling
Pros
Require no special features on server
Works in all browsers
Easy to implement in client
Cons
Bandwidth consuming
Monday, May 14, 12

22. HTTP Polling
Pros
Require no special features on server
Works in all browsers
Easy to implement in client
Cons
Bandwidth consuming
Large amounts of useless requests
Monday, May 14, 12

23. Piggyback
Browser Server
Timeline
Timeline
Monday, May 14, 12

24. Piggyback
Browser Server
Ajax Requst #1
Timeline
Timeline
Monday, May 14, 12

25. Piggyback
Browser Server
Ajax Requst #1
Response #1
Timeline
Timeline
Monday, May 14, 12

26. Piggyback
Browser Server
Ajax Requst #1
Response #1
Timeline
Timeline
Ajax Requst #2
Monday, May 14, 12

27. Piggyback
Browser Server
Ajax Requst #1
Response #1
Timeline
Timeline
Ajax Requst #2
Response #2
Monday, May 14, 12

28. Piggyback
Browser Server
Ajax Requst #1
Response #1
Timeline
Timeline
Ajax Requst #2
Response #2
Data/Event
Monday, May 14, 12

29. Piggyback
Browser Server
Ajax Requst #1
Response #1
Timeline
Timeline
Ajax Requst #2
Response #2
Data/Event
Data/Event
Monday, May 14, 12

30. Piggyback
Browser Server
Ajax Requst #1
Response #1
Timeline
Timeline
Ajax Requst #2
Response #2
Data/Event
Data/Event
Ajax Requst #3
Monday, May 14, 12

31. Piggyback
Browser Server
Ajax Requst #1
Response #1
Timeline
Timeline
Ajax Requst #2
Response #2
Data/Event
Data/Event
Ajax Requst #3
Mixed Response #3(with data)
Monday, May 14, 12

32. Piggyback
Monday, May 14, 12

33. Piggyback
Monday, May 14, 12

34. Piggyback
Pros
Monday, May 14, 12

35. Piggyback
Pros
Less resources consumption
Monday, May 14, 12

36. Piggyback
Pros
Less resources consumption
Works in all browsers
Monday, May 14, 12

37. Piggyback
Pros
Less resources consumption
Works in all browsers
No special requirements on server side
Monday, May 14, 12

38. Piggyback
Pros
Less resources consumption
Works in all browsers
No special requirements on server side
Cons
Monday, May 14, 12

39. Piggyback
Pros
Less resources consumption
Works in all browsers
No special requirements on server side
Cons
Server still have to wait for the request even though the
data/event has been arrived
Monday, May 14, 12

40. Comet:http streaming
Browser Server
Timeline
Timeline
Monday, May 14, 12

41. Comet:http streaming
Browser Server
Long-lived Request #1
Timeline
Timeline
Monday, May 14, 12

42. Comet:http streaming
Browser Server
Long-lived Request #1
Request is
suspended
Timeline
Timeline
Monday, May 14, 12

43. Comet:http streaming
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Monday, May 14, 12

44. Comet:http streaming
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response
Monday, May 14, 12

45. Comet:http streaming
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response
Data/Event
Monday, May 14, 12

46. Comet:http streaming
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response
Data/Event
Data/Event
Monday, May 14, 12

47. Comet:http streaming
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response
Data/Event
Data/Event
Response
Monday, May 14, 12

48. Comet:http streaming
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response
Data/Event
Data/Event
Response Data/Event
Monday, May 14, 12

49. Comet:http streaming
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response
Data/Event
Data/Event
Response Data/Event
Data/Event
Monday, May 14, 12

50. Comet:http streaming
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response
Data/Event
Data/Event
Response Data/Event
Data/Event
Response
Monday, May 14, 12

51. Comet:http streaming
Monday, May 14, 12

52. Comet:http streaming
Forever Iframe
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53. Comet:http streaming
Forever Iframe
Monday, May 14, 12

54. Comet:http streaming
Forever Iframe
Multipart xhr
(multipart/x-mixed-replace)
Monday, May 14, 12

55. Comet:http streaming
Forever Iframe
Multipart xhr
(multipart/x-mixed-replace)
Monday, May 14, 12

56. Comet:http streaming
Monday, May 14, 12

57. Comet:http streaming
Pros
Monday, May 14, 12

58. Comet:http streaming
Pros
Save the most bandwidth usage
Monday, May 14, 12

59. Comet:http streaming
Pros
Save the most bandwidth usage
Easy to implement(FI)
Monday, May 14, 12

60. Comet:http streaming
Pros
Save the most bandwidth usage
Easy to implement(FI)
Cons
Monday, May 14, 12

61. Comet:http streaming
Pros
Save the most bandwidth usage
Easy to implement(FI)
Cons
No way to implement error handling(FI)
Monday, May 14, 12

62. Comet:http streaming
Pros
Save the most bandwidth usage
Easy to implement(FI)
Cons
No way to implement error handling(FI)
Not supported by all the browsers(MX)
Monday, May 14, 12

63. Comet:http streaming
Pros
Save the most bandwidth usage
Easy to implement(FI)
Supported all the browsers(FI)
Cons
No way to implement error handling(FI)
Not supported by all the browsers(MX)
Monday, May 14, 12

64. Comet:Http Long Polling
Browser Server
Timeline
Timeline
Monday, May 14, 12

65. Comet:Http Long Polling
Browser Server
Long-lived Request #1
Timeline
Timeline
Monday, May 14, 12

66. Comet:Http Long Polling
Browser Server
Long-lived Request #1
Request is
suspended
Timeline
Timeline
Monday, May 14, 12

67. Comet:Http Long Polling
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Monday, May 14, 12

68. Comet:Http Long Polling
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response(#1 Completed)
Monday, May 14, 12

69. Comet:Http Long Polling
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response(#1 Completed)
Long-lived Request #2
Monday, May 14, 12

70. Comet:Http Long Polling
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response(#1 Completed)
Long-lived Request #2
Monday, May 14, 12

71. Comet:Http Long Polling
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response(#1 Completed)
Long-lived Request #2
Data/Event
Monday, May 14, 12

72. Comet:Http Long Polling
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response(#1 Completed)
Long-lived Request #2
Data/Event
Data/Event
Monday, May 14, 12

73. Comet:Http Long Polling
Browser Server
Long-lived Request #1
Request is
suspended
Data/Event
Timeline
Timeline
Response(#1 Completed)
Long-lived Request #2
Data/Event
Data/Event
Response(#2 Completed)
Monday, May 14, 12

74. Comet:Http Long Polling
Monday, May 14, 12

75. Comet:Http Long Polling
Script Tags
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76. Comet:Http Long Polling
Script Tags
Pros
Monday, May 14, 12

77. Comet:Http Long Polling
Script Tags
Pros
No Cross-Domain Messaging Issue
Monday, May 14, 12

78. Comet:Http Long Polling
Script Tags
Pros
No Cross-Domain Messaging Issue
Easy to implement
Monday, May 14, 12

79. Comet:Http Long Polling
Script Tags
Pros
No Cross-Domain Messaging Issue
Easy to implement
Cons
Monday, May 14, 12

80. Comet:Http Long Polling
Script Tags
Pros
No Cross-Domain Messaging Issue
Easy to implement
Cons
No way to implement error handling(FI)
Monday, May 14, 12

81. Comet:Http Long Polling
Script Tags
Pros
No Cross-Domain Messaging Issue
Easy to implement
Supported by all the browsers
Cons
No way to implement error handling(FI)
Monday, May 14, 12

82. Comet:Http Long Polling
Monday, May 14, 12

83. Comet:Http Long Polling
XMLHttpRequest
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84. Comet:Http Long Polling
XMLHttpRequest
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85. Comet:Http Long Polling
Monday, May 14, 12

86. Comet:Http Long Polling
XMLHttpRequest
Monday, May 14, 12

87. Comet:Http Long Polling
XMLHttpRequest
Pros
Monday, May 14, 12

88. Comet:Http Long Polling
XMLHttpRequest
Pros
Can implement good error handling
Monday, May 14, 12

89. Comet:Http Long Polling
XMLHttpRequest
Pros
Can implement good error handling
Easy to implement
Monday, May 14, 12

90. Comet:Http Long Polling
XMLHttpRequest
Pros
Can implement good error handling
Easy to implement
Supported by all the browsers
Monday, May 14, 12

91. Comet:Http Long Polling
XMLHttpRequest
Pros
Can implement good error handling
Easy to implement
Supported by all the browsers
Cons
Monday, May 14, 12

92. Comet:Http Long Polling
XMLHttpRequest
Pros
Can implement good error handling
Easy to implement
Supported by all the browsers
Cons
No main disadvantages
Monday, May 14, 12

93. Comet:Http Long Polling
XMLHttpRequest
Pros
Can implement good error handling
Easy to implement
Supported by all the browsers
Cons
No main disadvantages
Monday, May 14, 12

94. Bayeux
Just a protocol based on http
Monday, May 14, 12

95. WebSockets
Browser Server
Timeline
Timeline
Monday, May 14, 12

96. WebSockets
Browser Server
Timeline
Timeline
Monday, May 14, 12

97. WebSockets
Monday, May 14, 12

98. WebSockets
WebSockets enables
bi-direction, full-duplex communication
channel
like tcp sockets
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99. Thanks!
Monday, May 14, 12