Real-time fluent communication using

SignalR and Cloud

Radu Vunvulea

vunvulear@gmail.com

http://vunvulearadu.blogspot.com

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Who am I?

Agenda

• What?• When?• Where?• How?• Why?

• Static Web• HTML & Request/Response

•Ajax• jQuery & Prototype

•Real Time Web• Real Time Libraries & Web Socket

Real Time Interaction

• Chat• Notifications• Weather• Stock market• Auction• Games• Monitoring• Dashboard• Document editing

• WebSocket• Forever Frame• Server Sent Events• Pooling• SPDY

What we can use?

What we can use? • Commet• Pusher• SockJS• SocketIO• Faye• Now.js• Sse• Django-sse• Cramp

What we can use? • Commet• Pusher• SockJS• SocketIO• Faye• Now.js• Sse• Django-sse• Cramp

SignalR

What is SignalR?

• Async library for .NET to help build real-time, multiuser interactive web applications• Bidirectional communication• Open Source• Adopted by Microsoft • GitHub

When we can use it?

• Server• Windows (.NET)• Mono

• Clients• Chrome• Firefox• Safari• IE• Opera• Android browser• IoS• Windows Desktop• Silverlight• Windows Store• Windows Phone• and old browsers

Connection methods

• WebSocket• Server Side Events• Forever Frame• Ajax long pooling

Persistent Connection

• Similar with WebSocket• Persistent• Events• Connect• Disconnect• Receive• Error

• Methods• Send• Broadcast

Hubs

• Over Connections• Share variables• Calls between client and server• Serialization• Capture connect/disconnect

• Everything works by magic

Hubs

• When you have multiple hubs• Same connection is shared by a client• Groups are maintain separately for each hub• One proxy JS file for all hubs

• Async support

• OnConnected• OnDisconnected• OnReconnected• proxy.State (JS) & Client.Caller (C#)

Hubs vs Persistent Connections

Hubs• Remote invocation

Persistent Connections• Message format needs

to be specified• Messaging and

dispatching model• An existing app is

ported to SignalR

Security

• Based on Connection Token (Connection Id + Username)

• Unique• Managed by server• Encrypted with a digital signature

• Connection Id • Exist until the end of connection

• Username• Only for authenticated users• Passed between client and server for each request

CSRF and SignalR

• Disable cross domain requests• Verify connection token• Put connection token query string• The connection token is not persisted on the client

Performance

• Single Box• Over 450.000 messages per second• 15.000 – 20.000 connection (hardware limitations –

ports)

• Web farm• You have “NO” limit• You need to synchronize each node from the farm

SignalR Farm

• Backplanes:• Windows Azure Service Bus• Redis• SQLServer

• Server broadcast• High-frequency realtime• Client to client

Conclusion

• SignalR• Client to Server• Server to Client• Broadcasting• Real Time application• Scalable• Low latency

Question

Answers

THE END

Radu Vunvulea

vunvulear@gmail.com

http://vunvulearadu.blogspot.com