Deduplicate SignalR group messages across connections

[datwelk]

Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

When a SignalR connection is part of multiple groups, the connection will receive a message destined for the N-groups the connection is a part of also N-times. This leads to unnecessary overhead on the server, the network connection, and the client processing the messages.

Describe the solution you'd like

A common solution for this problem is to deduplicate on the client. This however does not take away the unnecessary network traffic, and requires client side processing.

Both DefaultHubLifetimeManager and RedisHubLifetimeManager know which connections belong to a group. Hence filtering can be done easily server side.

Additional context

No response