Removing user from group outside of hub

[lwansbrough]

I'd like to remove a user (all their connections) from a Signalr group without requiring their client's interaction. (For instance: kicking a user from a party/room.)

I recognize that I have a couple tools at my disposal:

IHubContext.Groups.RemoveFromGroupAsync(string connectionId, string groupName)
and
SignalR.Orleans.Core.HubContext.Group(groupName)

But neither the former nor the latter allow me to address a user by their user ID. How can I accomplish this?

One option I considered was getting all of a user's connection IDs, and iterating over RemoveFromGroupAsync, however the ConnectionGrain doesn't expose a method for getting the current connection IDs for a user/group.

[lwansbrough]

The same argument could be made for adding a user to a group from the backend. Right now, the only way to add a user to a group is to have their client send a request to the signalr hub. Ideally, I would be able to obtain a reference to the group and add the user by user ID.

I realize this is slightly outside the capability of Signalr, because Signalr assumes that a backplane doesn't know where on the cluster the user's connection is, but Orleans does know, so I think it's a reasonable extension for this particular backplane.