What is the suggested way to add timer and backgroundworker in a c# gRPC service

Question

To make it simple,

Let say I have a gRPC service:

At Startup.cs, I added the dependencies the services needed.

public void ConfigureServices(IServiceCollection services)
{
    services.AddGrpc();
    
    // Add dependencies
    services.AddSingleton<IDoSomething1, DoSomething1>();
    services.AddSingleton<IDoSomething2, DoSomething2>();
    services.AddSingleton<IDoSomething3, DoSomething3>();
    ...
}

It is working fine. But now, I want to do have some jobs running at the background (like querying a DB/another service for some updates).

Hence, I do something like below (using Timer + BackgroundWorker) at Program.cs.

public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
    .ConfigureWebHostDefaults(webBuilder =>
    {
        ...
        // Use the Startup class as shown above, so that I can using the dependencies added
        webBuilder.UseStartup<Startup>();
    }

public static void Main(string[] args)
{
    // CreateHostBuilder -> Startup -> Dependencies added
    using (var app = CreateHostBuilder(args).Build())
    {
        app.Start();

        // Use Timer + BackgroundWorker here
        BackgroundWorker backgroundWorker = new();
        backgroundWorker.DoWork += BackgroundWorker_DoWork;

        System.Timers.Timer timer = new();
        timer.Interval = 2000;
        timer.Enabled = true;
        timer.Elapsed += (object sender, System.Timers.ElapsedEventArgs args) => backgroundWorker.RunWorkerAsync(app.Services);
        
        app.WaitForShutdown();
    }
}

private static void BackgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
    IServiceProvider sp = (IServiceProvider)e.Argument;
    // Need to call GetRequiredService explicitly instead of automatically done by automatic constructor dependency injection
    IDoSomething1 doSomething1 = sp.GetRequiredService<IDoSomething1>();
    IDoSomething2 doSomething2 = sp.GetRequiredService<IDoSomething2>();
    IDoSomething3 doSomething3 = sp.GetRequiredService<IDoSomething3>();
    ...
}

Although the code above should work, it does not seems elegant to me, because it needs to call GetRequiredService explicitly instead of automatically done by automatic constructor dependency injection like the gRPC service class.

Is any better way to do so? I mean something like app.AddBackgroundJob(...)?

score 1 · Accepted Answer · answered Aug 29 '22 at 05:53

1

Check out BackgroundService class and especially Timed background tasks example which might be what are you looking for. Once your logic is implemented in such class it is plugged into ASP.NET via:

services.AddHostedService<TimedHostedService>();

answered Aug 29 '22 at 05:53

Ed'ka

6,595
29
30

Just took a look and had a simple try, it (AddHostedService + myOwnBackgroundService inheriting the abstract BackgroundService/myOwnTimedHostedService implementing IHostedService) is exactly what I want. It is well-integrated into the service framework with the lifetime coordination and allows the graceful shutdown. Thanks so much – kzfid Aug 29 '22 at 07:18
1

@kzfid if you are targeting the .NET 6 check out the [`PeriodicTimer`](https://learn.microsoft.com/en-us/dotnet/api/system.threading.periodictimer) for a more modern timer than the `System.Timers.Timer`, that doesn't allow overlapping invocations. – Theodor Zoulias Aug 29 '22 at 08:32
1

@TheodorZoulias Thanks for the suggestion, still at .Net 5. Will try that after being migrated to 6. – kzfid Aug 30 '22 at 01:36

What is the suggested way to add timer and backgroundworker in a c# gRPC service

1 Answers1