Asp.Net core long running/background task

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Is the following a correct pattern to implement long running background work in Asp.Net Core? Or should I be using some form of Task.Run/TaskFactory.StartNew with TaskCreationOptions.LongRunning option?

    public void Configure(IApplicationLifetime lifetime)
    {
        lifetime.ApplicationStarted.Register(() =>
        {
            // not awaiting the 'promise task' here
            var t = DoWorkAsync(lifetime.ApplicationStopping);

            lifetime.ApplicationStopped.Register(() =>
            {
                try
                {
                    // give extra time to complete before shutting down
                    t.Wait(TimeSpan.FromSeconds(10));
                }
                catch (Exception)
                {
                    // ignore
                }
            });
        });
    }

    async Task DoWorkAsync(CancellationToken token)
    {
        while (!token.IsCancellationRequested)
        {
            await // async method
        }
    }
2 Answers

Check also .NET Core 2.0 IHostedService. Here is the documentation. From .NET Core 2.1 we will have BackgroundService abstract class. It can be used like this:

public class UpdateBackgroundService: BackgroundService
{
    private readonly DbContext _context;

    public UpdateTranslatesBackgroundService(DbContext context)
    {
        this._context= context;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        await ...
    }
}

In your startup you just have to register class:

public static IServiceProvider Build(IServiceCollection services)
{
    //.....
    services.AddSingleton<IHostedService, UpdateBackgroundService>();
    services.AddTransient<IHostedService, UpdateBackgroundService>();  //For run at startup and die.
    //.....
}
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