Improve cross-links in Blazor server-side host doc

[guardrex]

Fixes #12445

Internal Review Topic

Improve cross-linking to content that pertains to hosing server-side Blazor.

[bradygaster]

this one 404'ed for me as did this one, and this one.

Aside from those dead links, which probably are only dead b/c I'm in review mode, this is great and much-appreciated.

[guardrex]

@bradygaster

this one 404'ed for me

Our relative links don't work on preview. All of the review topic links end up https://review.docs.microsoft.com/...... The "review" added there breaks all of the links. It's normal.

[bradygaster]

yes i know i just needed to call it out because ODC. :)

[guardrex]

oy @bradygaster ... It's a true honor and pleasure work'in with you. 🍻

[danroth27]

@guardrex I've looked through the proposed links and I think we need to say a bit more here about the need for a connection scale out solution for server-side Blazor apps. Instead of the "SignalR and Azure resources" section I think there should be a section called "Connection scale out" where we document that server-side Blazor apps require an active SignalR connection per user. Any production server-side Blazor deployment will need a solution for supporting as many concurrent connections as required by the app. Scaling up to lots of concurrent connection can be a difficult problem. That's what the Azure SignalR Service does for you and we strongly recommend using it.

Most of the Azure SignalR Service docs assume that the user is setting up SignalR themselves, but with server-side Blazor that's done for you. The hub used by Blazor is an implementation detail of the framework. So I think we need to explain this before sending folks off to the Azure SignalR Service docs to figure out which parts are relevant to them. Or we could just document the steps ourselves: 1. Provision the Azure SignalR Service, 2. Add the Azure SignalR Service package (Microsoft.Azure.SignalR), 2. Configure the connection string.

The next update to Visual Studio will do these steps for you when adding an Azure SignalR Service dependency to your app on publish. VS will also detect that your app is using SignalR/Blazor and recommend that you add the Azure SignalR Service dependency.

Eventually, we will also need to dramatically expand this topic to cover the various aspects of hosting server-side Blazor apps in production, like dealing with state persistence, but we should tackle that later in the Preview7 milestone.

[danroth27]

See my previous comment.

[bradygaster]

I do think it'd be great to keep the links outbound to the D&R and scale-out articles. Folks ask about those two things a lot, so if we pre-load those links up front it'd be good.

[guardrex]

I can finish this up after I work Add Azure SignalR Service to the SignalR publish-to-Azure page (#12744). It's in discussion at ...

#12744 (comment)

Once that content is in place (and I plan to work on that this weekend), I'll work this PR forward.

[guardrex]

@danroth27 I wordsmithed your lingo into two sections:

• Azure SignalR Service with a cross-link.
• Note that SignalR docs are generally for custom and advanced scenarios.

[danroth27]

A couple of minor nits.

[guardrex]

I'll merge this after the SignalR topic updates go in on #12764.

[guardrex]

@Rick-Anderson This was just on hold until #12764 merged, and that just happened. The changes here refer to updated coverage in that topic on that PR. This is ready for 🚀 LAUNCH! 🚀