2. Your Presenter
Shravan Kumar Kasagoni
Software Engineer @ Thomson Reuters
Microsoft MVP – ASP.NET / IIS | MCP
Microsoft User Group Hyderabad
http://theshravan.net
@techieshravan

3. Agenda
Introduction to real-time apps
What is SignalR?
Demos
SignalR Components
Scaleout SignalR

4. Real-time Application?
Real-time functionality is the ability to have
server code push content to connected clients
instantly as it becomes available, rather than
having the server wait for a client to request new
data.

5. Why Real-time?
Users want the latest info,
NOW!

6. Show Me Some Examples
 Twitter, Facebook, Mail - live searches/updates
 Stock streamers
 Auctions
 Interactive games
 Live Scores
 Collaborative apps (google docs, office web
apps)
 Live user analytics (live graphs)

7. How to build real-time web apps?

8. HTTP is an old beast…
Never designed for real-time
communications
 Web is all about request-response
 Web is stateless

10. Periodic polling
 Poll from time to time using Ajax
 Delay in communication due to polling interval
 Wastes bandwidth & latency
Server
Client
Polling interval

11. Long polling
 Poll but doesn’t respond until there's data
 Poll again after data received or after the connection
times out
 Consumes server & threads & connection resources
Server
Client

12. Forever Frame
 Server tells client that response is chucked
 Client keeps connection open until server closes it
 Server pushed data to the client followed by 0
 Consumes server threads
Server
Client

13. HTML5 Web sockets
 Extension to HTTP
 Provides raw sockets over HTTP
 Full-duplex
 Traverses proxies
 It's still a draft
 Not every proxy server supports it
 Not every web server supports it
 Not every browser supports it
 They are raw sockets!

14. too many options

17. What is SignalR?
An open-source series of libraries that provide an
abstraction around persistent HTTP connections
SignalR makes real-time HTTP so easy
it seems like magic that it works
[In English, please]

18. SignalR on Old Servers or Clients

19. SignalR on New Servers and Clients

20. Basically…

21. What does SignalR do?
 Client to Server Persistent connection
over HTTP
 Easily build multi-user, real-time web
applications
 Auto-negotiates transport

23. SignalR Fallback
Long
Polling
Forever
Frame
Server
Sent
Events
Web
Sockets

26. http://shootr.signalr.net
http://firework.cloudapp.net

28. CLIENTS
BACKPLANESHOSTS

30. Three backplanes
 Windows Azure Service Bus
 SQL Server
 Redis

31. Backplane
Load balancing via a common transport mechanism

32. References
http://www.asp.net/signalr/
http://signalr.net/
https://github.com/SignalR/SignalR/wiki

33. Keep in touch
http://theshravan.net
@techieshravan
shravan.kasagoni@outlook.com