SignalR Core scaling/hosting

Question

I have some questions regarding SignalR Core on the server side;

My server is written in ASP.NET Core, and it uses SignalR for sending notifications to users. The server uses Controllers with endpoints that clients interact with.

1) Can I host the entire thing in Azure App Service and add the SignalR service to it? Or would it be better to split the SignalR code out to its own server, which is called from the "main" server when needed?

2) The SignalR Service has an option for "Serverless", which according to documentation doesn't support clients calling any server RPCs when in said mode. Could I run this thing in Serverless mode as I'm only using the sockets for sending notifications to the clients. Or is it reserved for Azure functions?

3) Is there a way to get the number of connections for a user in a SignalR hub? I would like to send a push message to the user if he doesn't have any connections to the server. If not - what is the recommended way of handling this? I was thinking of adding a singleton service that keeps count, but am unsure if this would work at scale, especially with the SignalR service.

Thanks.

Answer 1

1) Better use the Azure SignalR.

2) Use it with the hub.

3) If you use Azure SignalR, you can just see it from the portal. In the code, whenever you use Azure SignalR or not, you can save the user Id in some var and count the connections. If you have multiple hubs and servers, you need to do more (if using redis-backplane for example).