Need help diagnosing the source of extremely slow response times in ASP.NET app service

Question

Disclaimer: I am not the person who created or configured our Azure account, services, or settings. I only know enough to be dangerous.

Our App Service is ridiculously slow to respond to client requests (measured in seconds, not milliseconds).

Facts:

1. It is written using ASP.NET and relies on ancient technologies. I am half way or so through the process of converting it to .NET 8, but it is not a cake walk.
2. Application Insights is enabled, but I have not enabled things like the profiler.
3. We are using one Premium v2 instance that will only scale out if it goes over 70% CPU utilization.
4. The SQL server's diagnostics and the app service's both look fine.
5. CSS and JS minimizer middleware is in place, and I have done obvious optimizations to decrease the response payload size in general.

I am looking for input from those that know more about this world than I do about things I can do in order to test and attempt to fix things that require fixing (there have to be several; there is no way everyone else's app services are this slow, or nobody would use them).

Thanks in advance

Answer 1

I don't think anything else is going to be more straightforward than capturing dumps when the slowness happens again,

https://learn.microsoft.com/en-us/troubleshoot/azure/app-service/capture-memory-dumps-app-service

But the challenge is whether you know how to analyze them and find the root cause, as that's not a trivial task.

To get assistance on that path, you might hire an experienced consultant, or open a support case with Microsoft support via https://support.microsoft.com