Category: NetCoreUsefullEndpoints

In the Nuget NetCoreUsefullEndpoints I have already an  endpoint to shutdown  –  see http://msprogrammer.serviciipeweb.ro/2023/02/20/netcoreusefullendpoints-part-9-adding-endpoints-for-shutdown/ .

However, this means that there are no ( or some … )  long running operations that are running … How to identify those ?

For the starting point , I was thinking at something simple, like an IDisposable that knows when the Long Running operation is finished

[HttpGet(Name = “GetWeatherForecast”)]
         public async Task<WeatherForecast[]> Get()
         {
             using var lr = UsefullExtensions.UsefullExtensions.AddLRTS(“weather”+DateTime.UtcNow.Ticks);
             await Task.Delay(5000);
             return Enumerable.Range(1, 5).Select(index => new WeatherForecast
             {
                 Date = DateTime.Now.AddDays(index),
                 TemperatureC = Random.Shared.Next(-20, 55),
                 Summary = Summaries[Random.Shared.Next(Summaries.Length)]
             })
             .ToArray();
         }

The implementation is very simple for adding:

internal static Dictionary<string, LongRunningTask> lrts = new();
public static LongRunningTask AddLRTS(string id, string? name = null)
{
     if(lrts.ContainsKey(id))
     {
         lrts[id].Dispose();
     }
     lrts.Add(id,new LongRunningTask(id, name ?? id));
     return lrts[id];
}

And for removing itself:

public record LongRunningTask(string id, string? name = “”) : IDisposable
{
     public void Dispose()
     {
         UsefullExtensions.lrts.Remove(id);
         GC.SuppressFinalize(this);
     }

}

Also, an endpoint will be registered for the user know what are the operations

var rh = route.MapGet(“api/usefull/LongRunningTasks/”,
             (HttpContext httpContext) =>
             {
                 var data=lrts.Select(it=>new { it.Key, it.Value.name }).ToArray();
                 return data;
             });

        var rhCount = route.MapGet(“api/usefull/LongRunningTasks/Count”,
             (HttpContext httpContext) =>
             {
                 return lrts.LongCount();
             });

And that will be to register and found what are the long running tasks in ASP.NET Core

In my NuGet NetCoreUsefullEndpoints package  I want to can shutdown the application . Could be hard way, like calling Environment.Exit or the easy way , like calling a cancellation token. Also, what should happen with all the requests that are coming ? ( And I do not want to mention long running tasks – I do not found a useful registration / un-registration for those)

So I come with the following implementation for forced exit

//IEndpointRouteBuilder

var rhForced = route.MapPost(“api/usefull/shutdownForced/{id:int}”,
     (int id) =>
     {
         Environment.Exit(id);
     });

For the shutdown that is requested , I come with 3 modifications:

1.In Program.cs , I put a Middleware for not serving the HTTP

builder.Services.AddSingleton<MiddlewareShutdown>();

app.UseMiddleware<MiddlewareShutdown>();

await app.RunAsync(UsefullExtensions.UsefullExtensions.cts.Token);

2.  Register the routes in order to use the cancellation token

//IEndpointRouteBuilder

var rhSec = route.MapPost(“api/usefull/shutdownAfter/{seconds}”,
             (HttpContext httpContext, int seconds) =>
             {
                 RequestedShutdownAt = DateTime.UtcNow;
                 var h = cts.Token.GetHashCode();
                 cts?.CancelAfter(Math.Abs(seconds)*1000);
                 return h;

            });

3. Use a middleware to return 418 Status Code if the application is shutting down

public class MiddlewareShutdown : IMiddleware
{
     public async Task InvokeAsync(HttpContext context, RequestDelegate next)
     {
         if (UsefullExtensions.RequestedShutdownAt != null)
         {
             context.Response.StatusCode = 418;
             await context.Response.WriteAsync(“Service is stopping at ” + UsefullExtensions.RequestedShutdownAt!.Value.ToString(“s”));
             return;
         }
         await next(context);
         return;
     }
}

And with those you can shutdown gracefully any ASP.NET Core application ( without long running tasks!)