More integration for Blazor Server and SignalR

[SteveSandersonMS]

@DamianEdwards:

Today in the typical case one ends up with multiple connections from the client to the server: one for the Blazor circuit, the other for the app’s SignalR hubs

I expect the key scenario here would be scaling out notifications across multiple servers via SignalR's backplane support (because otherwise, Blazor Server already inherently has notification/update support within a single server).

[TanayParikh]

Added to consolidated #38127. fyi/ @javiercn

[DamianEdwards]

@SteveSandersonMS it's also about the programming model. SignalR's Hub primitives include one-to-one and one-to-many RPC from server to client, including support for arbitrary grouping of clients, and yes these concepts then scale seamlessly to scaled-out deployments. Building a multi-user chat app in "pure" Blazor Server today is totally possible, but would require the app to manage some of the aspects inherent in such a scenario manually (e.g. there's no concept of invoking a method on multiple circuits).

Adding @bradygaster and @davidfowl for their thoughts.

[ghost]

Thanks for contacting us.

We're moving this issue to the .NET 8 Planning milestone for future evaluation / consideration. We would like to keep this around to collect more feedback, which can help us with prioritizing this work. We will re-evaluate this issue, during our next planning meeting(s).
If we later determine, that the issue has no community involvement, or it's very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues.
To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[mkArtakMSFT]

We haven't seen real-life scenarios where this is actually necessary. So closing for now.