Erratic extremely slow response from IIS with Native Module

Question

I have an issue with an IIS server taking forever to respond to requests that are handled by a C++ native IIS module set up as a handler for certain extensions. All installations (20+) of this module are running fine, except one.

Sometimes the server will return requests normally, in sub-second times, other times the same requests will go to an extreme and take 10, 20 minutes or more until they eventually return. When responses are poor, all responses are poor for a period of 30 minutes or more. Likewise, when it switches to fast times, responses times are consistently good for a period of 30 minutes or more.

The problem persists between application pool recycling and IIS server restarts. We haven't rebooted the host yet as it's handling a high load of data requests.

Sometimes the requests will return with 0.1-10 seconds, which is normal. Other times the same requests will take 10 - 40 MINUTES.

The main request I'm testing with doesn't need any external resources like databases or files and is simply return the server version, sometimes this can take 8 minutes.

The event logs are full of WAS Warnings:

A process serving application pool 'DefaultAppPool' failed to respond to a ping
A process serving application pool 'DefaultAppPool' suffered a fatal communication error with the Windows Process Activation Service.
A process serving application pool 'DefaultAppPool' exceeded time limits during shut down.

These warnings were 1 or a two almost daily up until the start of July and then increased sevenfold. The server was last rebooted about a week before then. We did not make any changes to the native module during this time, not the server and our customer likewise said no changes were made at the time (they leave it up to us to manage).

The Application event logs are getting a lot of:

Error,2/08/2021 8:10:33 p.m.,Application Error,1000,(100),"Faulting application name: w3wp.exe, version: 8.5.9600.16384, time stamp: 0x5215df96
Faulting module name: KERNELBASE.dll, version: 6.3.9600.20040, time stamp: 0x60adc0a6
Exception code: 0xe06d7363

After stopping and starting the IIS server or the application pool the requests will start responding again, but after 20-30 minutes the poor response times will be back.

The CPU, memory, disk and network performance all seem fine. The IIS settings for the pool and site are defaults as far as I can tell (I didn't configure it).

I'm currently at a loss where next to isolate the problem.

Answer 1

I had same issue
If you use .NET just update certificate for localhost (IE -> internet options -> Content -> Certificates).
In PowerShell:
dotnet dev-certs https –clean
dotnet dev-certs https –trust