SignalR firing OnConnectedAsync for users in a hub on another machine

Question

Our Azure SignalR application is a bit of a hybrid, outgoing messages go into ActiveMQ then get picked up by a listener in a hosted service that receives them and sends them to the NotificationsHub (in the same API project). e.g. await _notificationsHub.Clients.All.SendAsync("PerformAction", action, payload);

Recently I tried to extend this so that a second application using a different authentication scheme (this one is external facing, the existing one is internal facing) could connect and receive some messages (and send others back). I did a POC and everything seemed fine.

public class NotificationsHub : Microsoft.AspNetCore.SignalR.Hub {
  public override async Task OnConnectedAsync() {
    await Groups.AddToGroupAsync(Context.ConnectionId, "foo");
    await base.OnConnectedAsync();
    await Clients.Caller.SendAsync("SetConnectionId", Context.ConnectionId);
 }
}

Today I was debugging in Visual Studio the new application API and in the Hub's OnConnectedAsync method I kept receiving the "connected" events for users on a completely different server.

So my question is, does SignalR fire the "OnConnected" event for every hub connected to the same endpoint (for every instance of that hub)?

Even if that is the case wouldnt these two Hub classes be considered separate and not share their groups (see multiple hubs)?

Edit

For reference the project is targeting netcoreapp3.1, and using Microsoft.Azure.Signalr 1.8.1 in the original project and 1.16.1 in the new one.

Answer 1

It turns out that SignalR uses the name of the "Hub" class when connecting to the Azure SignalR service, i.e. 'wss://foo.service.signalr.net/server/?hub=notificationshub&cid={guid}'.

All hubs with the same name are treated as the same hub. I couldnt find that in the docs anywhere but it is implied in ApplicationName property of ServiceOptions which says "Gets applicationName, which will be used as a prefix to apply to each hub name"