Real time event feeds with NServiceBus and SignalR

In this session Mark Taling and I explain how we used NServiceBus and SignalR to publish real time events from a production monitor. After a short intro to NServiceBus and SignalR, we dive into some techniques for combining the two:

1) SignalR for relaying events from the back end to a wide range of clients
2) Using SignalR as a transport for NServiceBus
3) Using NServiceBus as a backplane for scaling out SignalR

Transcript

1. Real Time Event Feeds with NServiceBus and SignalR #SIGNALR #NSERVICEBUS #SDE @roycornelissen @marktaling
2. NServiceBus Combining the two SignalR Demos Introduction
4. Showcase: real time monitor gateway production monitor
5. [connect] monitor service Plugins gateway SendAvailablePlugins Powered By PluginAvailable (3x) Showcase: real time monitor
8. NServiceBus A service bus is an architectural style for integration To simplify communication between services in a distributed system
9. Loose coupling Share contract and schema, not class Temporal decoupling through queued messaging
10. Where is “the bus”? Like Ethernet, it’s everywhere!
11. A .NET framework to help implement SOA with the Service Bus architectural style Abstracts away transport, threading, queues, transactions Focuses on implementing business logic Highly pluggable
12. developers! developers! developers! Very developer focused
16. http has a pull model
17. The push concept The server takes the initiative to send data to the client
18. Push protocols irc smtp websocket server sent events
19. Two way, persistent connection, initiated by client W3C draft, worked on by IETF Support (partial) in some browsers
20. Server side events “Pub/Sub” like protocol over http Also still a W3C draft One-way, client needs extra channel for send Proxies need to know about content-type:text/event-stream
21. But I want it now! Veruca Salt Willy Wonka & The Chocolate Factory, 1971
22. Other options client 2 server POST “message” client 1 Got msg? “message” long polling POST “message” Got msg? “message” client 2 server POST “message” client 1 GET /forever <script> display(“message”); </script> forever frame POST “message” <script> display(“message”); </script> <iframe src=“/forever”>
23. SignalR to the rescue
24. SignalR’s layers of abstraction SignalR will abstract away the actual protocol used, and adds a couple of layers on top to make things even easier
25. protocols persistent connection hub web sockets server events long polling forever frame • Unified programming model • Deals with connectivity issues (connection slow, reconnect, disconnects) • Available for multiple types of clients • Messaging bus • Utilizes Json.NET for serialization SignalR 1.0
26. hubs
27. Client/server boundaries fade Hubs let you provide a semantic API between client and server SignalR creates a proxy between the two parties client (javascript) var chat = $.connection.chatHub; … chat.server.message(“hi!”); … chat.client.notify = function(text) { // do something with text } server class ChatHub: Hub { public void message(string text) { Clients.All.notify(text); } } proxy dynamic
29. SignalR options JavaScript .NET Windows Phone Silverlight WinRT iOS Android ASP.NET OWIN Custom SQL Redis Service Bus clients hosts backplanes
31. Gateway Monitor Service Gateway IIS AppFabric input queue input queue MonitorHub: Hub NServiceBus MessageForwarder: IHandleMessages<T> GlobalHost .ConnectionManager .GetHubContext<MonitorHub>();.
33. Transport Monitor Service Gateway IIS AppFabric SignalR NServiceBus input queue input queue MonitorHub: Hub NServiceBus
35. Transparent: no notion of SignalR NServiceBus in the client SignalR transport The Good
36. No guaranteed delivery No transaction support SignalR transport The Bad
37. Scaling out SignalR via backplanes B NServiceBus ?
38. An NServiceBus backplane Backplane Service SignalR IIS AppFabric input queue NServiceBusMessageBus: ScaleoutMessageBus NServiceBus Receiver: IHandleMessages<MessagesAvailable> Bus.Send<DistributeMessage>() MessageDispatcher: IHandleMessages<DistributeMessage> Bus.Publish<MessagesAvailable>() OnReceived(…);. input queue
40. Reliability offered by NServiceBus What about scalability of the backplane service itself? SignalR backplane Considerations
41. Links www.nuget.org www.nservicebus.com www.github.com/nservicebus www.udidahan.com www.github.com/signalr www.github.com/gshackles/signalr
42. @roycornelissen royc@infosupport.com roycornelissen.wordpress.com thanks! @marktaling markt@infosupport.com