.NET Core issue: System.OperationCanceledException when hosted in IIS - api

Question

My program.cs file in .NET Core 3.1 is like this I am creating web API in .net core but I am getting this error when hosted on server in IIS. API is working fine when hosted locally.
public class Program
{
public static void Main(string[] args)
{
var logger = NLogBuilder.ConfigureNLog(String.Concat(Directory.GetCurrentDirectory(), "/nlog.config")).GetLogger();
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
}).ConfigureLogging(logging =>
{
logging.ClearProviders();
logging.SetMinimumLevel(Microsoft.Extensions.Logging.LogLevel.Trace);
})
.UseNLog();
}
System.OperationCanceledException: at program.cs error
I am getting this error with stack trace like:
Description: The process was terminated due to an unhandled exception.
Exception Info: System.OperationCanceledException: The operation was canceled.
at System.Threading.CancellationToken.ThrowOperationCanceledException()
at System.Threading.CancellationToken.ThrowIfCancellationRequested()
at Microsoft.Extensions.Hosting.Internal.Host.StopAsync(CancellationToken
cancellationToken)
at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.WaitForShutdownAsync(IHost
host, CancellationToken token)
at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost
host, CancellationToken token)
at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost
host, CancellationToken token)
at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.Run(IHost
host)
What is wrong here?

Answer 1

I am experiencing the same error, and I was trying to see what might cause it.
I came across this link with the same issue
and the thing that jumped out at me was the "non-graceful shutdown". To test, I recycled the application website on IIS, which did not trigger the error. I then tried turning off the app pool via IIS, and DID trigger the exception.
This leads me to believe it has something to do with a task running inside the application that is cut short when the non-graceful shutdown occurs.
In my case, I have a HostedService running in the background of my application, do you have something similar in yours?