We confronted a strange situation today that all of sudden our IIS stopped responding to requests upon checking the worker process everything looked fine there. Moreover, the Pool was working fine as well. Restarting the IIS poll threw an error "0x80070425" after waiting for a minute we then tried again and it worked but even at that point server was not accepting requests everything got queued. Anyways, moving on we then decided to run the command "iisreset" afterwards we found that process ID 4 is listening on port 80 and port 443 which isn't an IIS process and the process having ID 4 name was "System". Upon checking the headers at this particular point we came to know that requests are being served through "Microsoft HTTPAPI/2.0". Moving on, we then reattached the pool to the same website over again and the website started responding but we have to re-upload builds (DLLs) for the websites to work properly.
What are the possible ways to debug this issue?
Env Information:
Server: Windows Server 2016
Framework .NET Framework 4.5 and ASP.NET Runtime 4.0.0
Build: x64
PS: At the time when this error occurred we literally have 0 requests being served at that time. Windows Logs Viewer seems fine no Uncaught Exception was caught in our system
