The document discusses the state of the real-time web and summarizes that it is not fully realized yet. It covers various approaches to real-time applications including shared nothing architectures, message buses, Node.js with Socket.io, and Google App Engine. It also discusses commercial services like PubNub and Pusher and their limitations. The document advocates for a better approach that supports duplex communication, broadcasting, access rights, identity, presence, authorization, resource definitions, value updates, and webhooks. It suggests building such a service would require good documentation. Finally, it introduces SockJS as a way to abstract different real-time transport options and points to its GitHub page for more information.

1. Realtime web:
Not there yet!
Marek Majkowski
marek@rabbitmq.com
1

2. Nogi
2

3. 3

4. 4

5. 5

6. 6

7. 7

8. WebSockets
hixie-75 4 5.0.0
4 11
hixie-76 6 5.0.1
(disabled) (disabled)
hybi-07 6
hybi-10 7 14 10-dev
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9. Spot the difference!
$ nc localhost 8080 $ nc localhost 12345
GET /broadcast/765/321/websocket HTTP/1.1 GET /echo HTTP/1.1
Origin: http://172.16.173.128:8080 Origin: http://172.16.173.128:12345
Host: 172.16.173.128:8080 Host: 172.16.173.128:12345
Connection: Upgrade Connection: Upgrade
Upgrade: WebSocket Upgrade: WebSocket
Sec-WebSocket-Key2: `1]2037 7 GX 'f<Vb1*5$64 Sec-WebSocket-Key2: `1]2037 7 GX 'f<Vb1*5$64
Sec-WebSocket-Key1: 2Uf ?<,4C28E1K7J4+208 Sec-WebSocket-Key1: 2Uf ?<,4C28E1K7J4+208
Cookie2: $Version=1 Cookie2: $Version=1
Cookie: JSESSIONID=a Cookie: JSESSIONID=a
aaaaaaaaaaaaaaa aaaaaaaaaaaaaaa
HTTP/1.1 101 WebSocket Protocol Handshake HTTP/1.1 101 WebSocket Protocol Handshake
Upgrade: websocket Upgrade: WebSocket
Connection: Upgrade Connection: Upgrade
Sec-WebSocket-Location: ws://[...] Sec-WebSocket-Location: ws://[...]
Sec-WebSocket-Origin: http://[...] Sec-WebSocket-Origin: http://[...]
m"7]SDgo0 m"7]SDgo0
^C ^C
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10. The RFC says
-> If the entry's name is "upgrade"
If the value is not exactly equal to the string "WebSocket",
then fail the WebSocket connection and abort these steps.
[...]
|Upgrade|
The value must be the string "WebSocket".
[...]
|Upgrade|
Invariant part of the handshake. Will always have a value
that is an ASCII case-insensitive match for the string
"WebSocket".
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11. Proxies
GET /echo/070/lm6wwjpr/websocket HTTP/1.1 CONNECT sockjs1.popcnt.org:80 HTTP/1.1
Host: sockjs1.popcnt.org Host: sockjs1.popcnt.org
User-Agent: [...] Gecko/20100101 Firefox/6.0.2 Proxy-Connection: keep-alive
Accept: text/html,application/xhtml [...]
Accept-Language: en-us,en;q=0.5 GET /echo/855/duzzy2p1/websocket HTTP/1.1
Accept-Encoding: gzip, deflate Upgrade: WebSocket
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Connection: Upgrade
Sec-WebSocket-Version: 7 Host: sockjs1.popcnt.org
Sec-WebSocket-Origin: http://sockjs.popcnt.org Origin: http://sockjs.popcnt.org
Sec-WebSocket-Key: bzG4fOYXabSiy42uFj6vjA== Sec-WebSocket-Key1: 22p/ D"47900%n7 r90.
Pragma: no-cache Sec-WebSocket-Key2: m49" 5 f 24772 Ra
Cache-Control: no-cache
Upgrade: websocket
Connection: Upgrade
HTTP/1.0 400 Bad Request
Server: squid/2.7.STABLE9
Date: Wed, 21 Sep 2011 06:16:10 GMT
Content-Type: text/html
Content-Length: 1943
X-Squid-Error: ERR_INVALID_REQ 0
X-Cache: MISS from mrstu
X-Cache-Lookup: NONE from mrstu:3128
Via: 1.0 mrstu:3128 (squid/2.7.STABLE9)
Connection: close
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12. • #1 Realtime web: Not there yet!
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13. Shared nothing + database
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14. Shared nothing + message bus
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15. Node.js + Socket.io
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16. Sync + Async
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17. Sync + Service
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18. 18

19. Google App Engine
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20. Google App Engine
• Simplex
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21. Google App Engine
• Simplex
• No broadcast
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22. Google App Engine
• Simplex
• No broadcast
• No presence
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23. PubNub
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24. PubNub
• Duplex
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25. PubNub
• Duplex
• Broadcast
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26. PubNub
• Duplex
• Broadcast
• No access rights
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27. PubNub
• Duplex
• Broadcast
• No access rights
• No identity
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28. Pusher
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29. Pusher
• Simplex
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30. Pusher
• Simplex
• Broadcast
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31. Pusher
• Simplex
• Broadcast
• Access rights *
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32. Pusher
• Simplex
• Broadcast
• Access rights *
• Identity *
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33. Pusher
• Simplex
• Broadcast
• Access rights *
• Identity *
• Presence *
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34. We can do better
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35. We can do better
• Duplex
22

36. We can do better
• Duplex
• Broadcast
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37. We can do better
• Duplex
• Broadcast
• Access rights
22

38. We can do better
• Duplex
• Broadcast
• Access rights
• Identity
22

39. We can do better
• Duplex
• Broadcast
• Access rights
• Identity
• Presence
22

40. 23

41. • Authorisation
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42. • Authorisation
• Identity
23

43. • Authorisation
• Identity
• Permissions
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44. • Authorisation
• Identity
• Permissions
• Resource definitions + semantics
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45. • Authorisation
• Identity
• Permissions
• Resource definitions + semantics
• Value + updates?
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46. • Authorisation
• Identity
• Permissions
• Resource definitions + semantics
• Value + updates?
• Messages back to App (WebHooks)
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47. • Authorisation
• Identity
• Permissions
• Resource definitions + semantics
• Value + updates?
• Messages back to App (WebHooks)
• Presence
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48. • Authorisation
• Identity
• Permissions
• Resource definitions + semantics
• Value + updates?
• Messages back to App (WebHooks)
• Presence
• Good luck writing documentation!
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49. Service?
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50. Sync + Async
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51. Fully async
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52. SockJS
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53. • #3 Realtime web: Not there yet!
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54. 29

55. 30

56. #sockjs
github.com/sockjs
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57. 1. token
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58. 2. token
33

59. 3. token
34

60. So?
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61. 36