C#•3y ago

❔ how do delay the process exit for a graceful shutdown in a console app?

Hey, I want to delay the app exit by a few seconds, I tried using the following but it's just exiting instantaneously

AppDomain.CurrentDomain.ProcessExit += delegate(object sender, EventArgs eventArgs)
        {
            GlobalState.CancellationRequested = true;
            LogService.EzLogger.LogInfoAsync("[PROCESSOR] Shutting down gracefully", null);
            Console.WriteLine("Shutting down...");  
            Thread.Sleep(TimeSpan.FromSeconds(30));
            Console.WriteLine("Finished shutting down...");
        };

AppDomain.CurrentDomain.ProcessExit += delegate(object sender, EventArgs eventArgs)
        {
            GlobalState.CancellationRequested = true;
            LogService.EzLogger.LogInfoAsync("[PROCESSOR] Shutting down gracefully", null);
            Console.WriteLine("Shutting down...");  
            Thread.Sleep(TimeSpan.FromSeconds(30));
            Console.WriteLine("Finished shutting down...");
        };

AppDomain.CurrentDomain.ProcessExit += delegate(object sender, EventArgs eventArgs)
        {
            GlobalState.CancellationRequested = true;
            LogService.EzLogger.LogInfoAsync("[PROCESSOR] Shutting down gracefully", null);
            Console.WriteLine("Shutting down...");  
            Thread.Sleep(TimeSpan.FromSeconds(30));
            Console.WriteLine("Finished shutting down...");
        };

AppDomain.CurrentDomain.ProcessExit += delegate(object sender, EventArgs eventArgs)
        {
            GlobalState.CancellationRequested = true;
            LogService.EzLogger.LogInfoAsync("[PROCESSOR] Shutting down gracefully", null);
            Console.WriteLine("Shutting down...");  
            Thread.Sleep(TimeSpan.FromSeconds(30));
            Console.WriteLine("Finished shutting down...");
        };

IsNotNull•8/4/23, 2:38 PM

If I had to have something safe exit, I'd run it in an OS service.

We had to try and capture exit from a UI app once (to avoid corrupting a QuickBooks file we were connected to), and it was a pain that almost never worked. You'd still have to deal with OS crashes and hard drive failures anyways.

TigerOP•8/4/23, 2:40 PM

I do

TigerOP•8/4/23, 2:40 PM

but I want to just stop some background workers

TigerOP•8/4/23, 2:40 PM

it's better if it's graciously exiting

TigerOP•8/4/23, 2:41 PM

but it will handle crashes

IsNotNull•8/4/23, 2:46 PM

Your process is in a service, and you need to stop other background workers. Are the background workers running in the same process? Are they ones you started yourself as part of the service?

IsNotNull•8/4/23, 2:47 PM

@IUndisposable<Fleksi>

IIsNotNull Your process is in a service, and you need to stop other background workers. Are...

TigerOP•8/4/23, 2:53 PM

it's a console app that starts while(true) tasks

TigerOP•8/4/23, 2:53 PM

I stop them via a global bool

TigerOP•8/4/23, 2:54 PM

this allows me to control exactly when I can stop "safely" in the task

IsNotNull•8/4/23, 2:54 PM

Why not just pass them a CancellationToken when they start?

TigerOP•8/4/23, 2:54 PM

I could

TigerOP•8/4/23, 2:54 PM

but that's not the issue

IsNotNull•8/4/23, 2:55 PM

Signalling that the subtasks have finished is your issue?

TigerOP•8/4/23, 2:55 PM

I want to delay the exit of my process, token or bool doesn't matter

TigerOP•8/4/23, 2:55 PM

signaling works fine

TigerOP•8/4/23, 2:55 PM

it's the process that exits too quickly

IsNotNull•8/4/23, 2:56 PM

When I've used windows services (using the service worker dotnet new template) it has a shutdown method...I was under the impression the OS will wait for services to shutdown a certain amount of time before they force them closed? Is that not the case?

TigerOP•8/4/23, 2:56 PM

yeah but this is a console app

TigerOP•8/4/23, 2:57 PM

and the event handler is supposed to do that

IsNotNull•8/4/23, 2:57 PM

Ah, its not a service

TigerOP•8/4/23, 2:57 PM

but it seems to not wait even if I ask it to

IsNotNull•8/4/23, 2:58 PM

I remember with the app I mentioned earlier that we had to try two or three different approaches before we found one that would 'usually' work

TigerOP•8/4/23, 2:58 PM

ok so I just did some debugging

IsNotNull•8/4/23, 2:58 PM

I think we were calling into a win32 api. Not sure that would help you much if you are looking for a cross platform approach

TigerOP•8/4/23, 2:58 PM

it seems to wait 10 seconds now

TigerOP•8/4/23, 2:58 PM

so now I gotta configure docker to wait for longer

IsNotNull•8/4/23, 2:59 PM

I think the issue we ran into was that the process was getting killed when the terminal window was being closed, so it still wasn't 'shutting down'

TigerOP•8/4/23, 2:59 PM

well I used ctrl+c

TigerOP•8/4/23, 2:59 PM

idk

IsNotNull•8/4/23, 2:59 PM

Like, ctrl-c was fine, but 'x' on the terminal still broke it

IsNotNull•8/4/23, 3:00 PM

Is this for your db project?

TigerOP•8/4/23, 3:01 PM

no we are switching over to kubernetes at work

TigerOP•8/4/23, 3:02 PM

so I need to implement some safe exits since kube randomly kills off processes

TigerOP•8/4/23, 3:02 PM

also the db is C++

TigerOP•8/4/23, 3:02 PM

anyways thanks

TTiger also the db is C++ 😛

IsNotNull•8/4/23, 3:26 PM

I remembered that, but I wasn't sure if you had a C# host process. Figured I'd ask, since unexpected db shutdown is a pretty sensitive topic and I'm curious how people deal with it

IIsNotNull I remembered that, but I wasn't sure if you had a C# host process. Figured I'd a...

TigerOP•8/4/23, 3:28 PM

well usually you will have a commit log that holds the data as a copy

TigerOP•8/4/23, 3:28 PM

and you have a bunch of flags in your binary document file

TigerOP•8/4/23, 3:28 PM

basically you would have a flag telling that the document is no corrupted

TigerOP•8/4/23, 3:29 PM

when editing the data you copy data to the commit log, then unset the corrupt flag while editing the data

TigerOP•8/4/23, 3:29 PM

once done, you but the flag back and delete the log

TigerOP•8/4/23, 3:30 PM

then it's all upto the parser to check the log if the document is corrupted and get the data from the log itself

TigerOP•8/4/23, 3:30 PM

this does however slow down the process by quite a a bit

TigerOP•8/4/23, 3:30 PM

so you'd usually have a few background threads doing that work in chunks

IsNotNull•8/4/23, 3:31 PM

You are reminding me why I liked working on an append only database with row-by-row records. I just throw out any incomplete rows harold

TigerOP•8/4/23, 3:32 PM

haha

IIsNotNull You are reminding me why I liked working on an append only database with row-by-...

TigerOP•8/4/23, 3:32 PM

also my db will feature a "return uncommitted" insert

TigerOP•8/4/23, 3:32 PM

so you can basically insert data as a fire and forget

TigerOP•8/4/23, 3:33 PM

useful for storing non-crucial data, such as system logs among others

❔ how do delay the process exit for a graceful shutdown in a console app?

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