Correlation/concurrency issues with UseAzureMonitor & WebApplicationFactory<T>.

[KennethHoff]

I was directed by @tarekgh here to create an issue in this repository, so here I am 👋

There are more details in the issue linked (dotnet/runtime#98854), but the gist of it is this: Adding UseAzureMonitor causes my integration tests to "blow up"; It's causing some immense concurrency and/or correlation issues.

Without UseAzureMonitor I have no concurrency and/or correlation issues (Only some inconsistencies in the name of the activity, which is a different issue entirely I reckon, not related to Azure).

With UseAzureMonitor however there is something happening (be that concurrency or correlation - I don't know) that's causing my integration tests to fail when running them in parallel, but work fine when I'm running them sequentially.

Later in the thread I did find a partial workaround (With its own set of problems), but the general issue stands; Something fishy is going on with UseAzureMonitor.

In case the issue over on dotnet drops or I do a lot of changes to the repro during research, here's a direct link to the GitHub repo before adding the partial workaround: https://github.com/KennethHoff/Repros/tree/b25106f575ee5c782f99dfcfe89b5fc6eb53a900/ActivityTesting