ASP.NET Core Series: SignalR

ASP.NET Core SignalR is an open source library that makes that helps developers add real-time web functionality to their applications.
In this episode, Christos chats with our friend Brady Gaster from the ASP.NET Team. Brady gives quick overview of what we can do with SignalR as well as highlights some of the new features the team has been working on.
[00:58] - What's new with ASP.NET Core ?
[05:05] - What is SignalR?
[07:00] - (Demo) Connecting browsers with a SignalR Hub
[12:14] - Enabling WebSockets on Azure App Service.
[14:20] - Connection durability and reconnects
[17:51] - Client targeting
[19:00] - Scaling out a SignalR backend
Introduction to ASP.NET Core SignalR
docs.microsoft...
ASP.NET Core updates in .NET 5 Preview 6
devblogs.micro...
Use ASP.NET Core SignalR with TypeScript and Webpack
docs.microsoft...

[@Byrthor]

This was a perfectly timed video. I'm in the process of converting our old SingalR service to the updated Net Core version.

[@ScottGrunwald]

To Brady and Team, he mentioned at 4:15 to use, "asp.net CORE signal R" NOT "non Core version" for Blazor wasm. However, when I ran through the tutorial on the docs (docs.microsoft.com/en-us/aspnet/core/tutorials/signalr-blazor-webassembly?view=aspnetcore-3.1&tabs=visual-studio) ... I ran into compilation errors with the "Core" version. So, I ran through it again using the Non-Core version as the doc says to use, and it worked fine. Just wanted to point that out.

[@mt89vein]

thanks for the video. I have a several questions.
1. Is it possible to use single websocket connection for all hubs in single webapp ?
2. how many connections can be handled by one signalR server ?
3. how many RAM required for handling per websocket connection? (e.g. read/write buffers, internal structures)
4. how can i check is some user is online when using redis backplane. If i understand correctly, signalR manages it's own internal state for connections in webapp, not in redis (or another backplane), and for checking is some user online we should expose http method and query all webapps, or self-maintain list of active connections e.g. override onConnect, onDisconnect and write to redis.

[@santosharakere]

Excellent presentation, thanks.

[@ScottGrunwald]

Could you please link all of the resources that Brady mentioning at the intro? Would love to check out all of those mentioned SignalR resources!

[@chadgregory9037]

So for an example, if I have an SQL join table that connects a conversationId with a participant Id, I can have a function that will query my database (if not already loaded) and then create a new group from a list of participants in a conversation, and then pass that group as an argument into the SignalR and it will push the message to the appropriate recipients ? What about if they aren't logged in, will it automatically ignore the push for that client, or will it throw some kind of error, and I have to explicitly state to only push it to logged in members that are recipients of the conversation?

[@AdamsTaiwan]

I created a workflow in which a web client submits a job request. A winservice starts the long running process with the progress send back to the web client via signalR. The hard part will be to limit what group it goes to and allow the client to queries groups available. I think I need a third category for jobID within a group.

[@bibinlouis4927]

Fabulous video :)

[@hashmsalim8521]

I can't find the link to the repository in the description

[@adinwashere]

I used SignarR a couple of years ago on a Webforms website. It was pretty cool but not easily scalable

[@furkanbozkurt2485]

hey, I'm new to this stuff. What library do you recommend other than SignalR

[@adinwashere]

@@furkanbozkurt2485 If you know your website won't need to scale out to multiple servers then SignalR is a good idea. We ended up using good old fashioned polling, meaning our JS would do an AJAX call to the server every few seconds to check if there is something new

[@furkanbozkurt2485]

@@adinwashereThx for reply. Actually I've already done signalr. But then I learned that it's not easly scalable. My web service should scale out thus I need someting scalable.

[@willinton06]

@@furkanbozkurt2485 if you use azure you’ll be able to scale it to the moon if you need to

[@Time21]

more about SignalR please....internet is full of chat apps. We need something different please

[@AndyPook]

please do not use fancy fonts and ligatures in demos.
makes it harder to parse what's being shown

[@furkanbozkurt2485]

Thanks for demo but please consider slowing down your talking speed. Also can you pronounce the words more explicitly? Not all of us Americans sadly. It was hard to catch. Thank you.