Server-triggered circuit pause section updates

[guardrex]

Fixes #37145

Wade, this comes from Ilona's feedback on #37133. She's OOF at the moment, and we can go ahead with this based on your review. When she sees my remarks below, she can comment on if I broke anything with my updates. If I did break something, I'll issue a patch PR later, probably sometime next week.

Ilona ... Thanks so much for the implementation updates to Javier's original code. I think devs are really going to ❤️ this feature and the implementation example that you provided. You don't need to look at the whole thing, but this one paragraph might need a little more work. I applied some grammar and style manual updates that might have 💥 some of the concepts 🙈😆. That paragraph currently goes like this (Line 229 on the diff) ...

Using the following approach, the fact that the code sends the `RequestCircuitPauseAsync` asynchronously doesn't mean that upon returning the value that the client is already paused. It's only a request to pause the client, which the client can defer. That's why the code includes the <xref:System.Threading.Tasks.TaskCompletionSource> (`_shutdownTcs`), which is set when there aren't any circuits connected (all of them are successfully shut down). In case a client requests a deferral longer than the server allows, longer than `ShutdownTimeout`, the client doesn't persist state and experiences a normal connection loss. Other clients that don't defer the pause request have their connections re-established after the app goes back online with state persisted.

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Internal previews

📄 File	🔗 Preview link
aspnetcore/blazor/state-management/server.md	aspnetcore/blazor/state-management/server
aspnetcore/host-and-deploy/health-checks.md	aspnetcore/host-and-deploy/health-checks
aspnetcore/release-notes/aspnetcore-11.md	aspnetcore/release-notes/aspnetcore-11

[guardrex]

@tdykstra @wadepickett ... This popped up here ...

aspnetcore/host-and-deploy/health-checks.md
Line 186: [Warning] Cross reference not found: 'Microsoft.Extensions.DependencyInjection.EntityFrameworkCoreHealthChecksBuilderExtensions.AddDbContextCheck*'.

aspnetcore/host-and-deploy/health-checks/includes/health-checks6-7.md
Line 169: [Warning] Cross reference not found: 'Microsoft.Extensions.DependencyInjection.EntityFrameworkCoreHealthChecksBuilderExtensions.AddDbContextCheck*'.

No worries! I'll fix it on this PR.

[guardrex]

Ah!!! @tdykstra, @wadepickett ... and looping in @BillWagner (👋 Bill ... hope ur well!!!) .....

There's an API Browser regression. The API for ...

Microsoft.Extensions.DependencyInjection.EntityFrameworkCoreHealthChecksBuilderExtensions.AddDbContextCheck

... shows up ...

... but there's no API for it. Clicking the link results in a 404 ...

https://learn.microsoft.com/en-us/dotnet/api/microsoft.extensions.dependencyinjection.entityframeworkcorehealthchecksbuilderextensions.adddbcontextcheck#microsoft-extensions-dependencyinjection-entityframeworkcorehealthchecksbuilderextensions-adddbcontextcheck-1

I'm going to code-fence the API in these markdown files for now to unblock this PR. I'll open a new issue to put the XREF links back after the API Browser comes back online with the bits.

UPDATE: Done! 👍 I've opened ...

Reactivate XREF cross-links after API Broswer regression is addressed
#37147

... to reactivate the XREF cross-links in the markdown files after the API shows back up.

[wadepickett]

@guardrex, approved. Looks great. One crucial item in the code to fix before you merge. I noted it inline.

[guardrex]

Thanks for spotting that, @wadepickett!

[wadepickett]

@guardrex, For Microsoft.Extensions.DependencyInjection.EntityFrameworkCoreHealthChecksBuilderExtensions.AddDbContextCheck:

It does exist in the API Ref:
AddDbContextCheck on Microsoft Learn

Looks like the xref cross-reference sysetem can't resolve the wildcard link?
xref:Microsoft.Extensions.DependencyInjection.EntityFrameworkCoreHealthChecksBuilderExtensions.AddDbContextCheck*

So by regression, you mean the xref cross-ref system used to handle wildcards like this but now they are not resolving, correct? (As opposed to the API Ref regressing and a once documented reference item is now missing)

[guardrex]

Not sure. Let me check again on that. Maybe it was a passing problem.

[guardrex]

Your link and this ...

https://learn.microsoft.com/en-us/dotnet/api/?term=Microsoft.Extensions.DependencyInjection.EntityFrameworkCoreHealthChecksBuilderExtensions.AddDbContextCheck

... results in a 404 for me ...

... and the XREF breaks this PR.

I hazard a guess that there's a regression in the API Browser or how the API Browser is being served out here in my local area.

[guardrex]

a once documented reference item is now missing

I think so. I'm going by the build report and the 404 in the API Browser. The build report threw ...

https://buildapi.docs.microsoft.com/Output/PullRequest/332f35cd-658d-4914-0f85-907e40ee89f0/202605131739242434-37146/BuildReport?accessString=ff106d11859c8f58ec44cf75059ca607f87bfb1d572f3a443b44136b799d13af

I suggest that we code-fence for now to unblock this and go back to the proper XREF links, which is tracked by #37147. If you and Tom want, I'll babysit that issue until this is sorted out.

In passing tho, I still disagree that a build report warning in an unrelated article should block a PR. I think that's a poor process choice.

[wadepickett]

"In passing tho, I still disagree that a build report warning in an unrelated article should block a PR. I think that's a poor process choice."

I do not think a build report warning on an unrelated article should ever block a PR. We are on the same page.

[guardrex]

I'll go ahead with this so that we have a great example from Ilona on how to implement the new API.

I'll take that issue that I opened and keep an eye on the API Browser. I think Alma Jenks was helping us with these API-related problems. I'll ping him on that issue to ask about it. However, let me know if he's the wrong cat to discuss it with.

[wadepickett]

Intersting:
Going here in the API browser, the class below shows up in the list, but it is 404 if you click on the class link:
https://learn.microsoft.com/en-us/dotnet/api/?term=entityframeworkcorehealthchecksbuilderextensions

[guardrex]

Yes, that's what I'm seeing here.

Let's take this up on the issue that I opened at #37147.