Timer doesn't start on start of service.

[ShelestSergey]

I have service using SoapCore.
There's some transient SoapEndpoints
builder.Services.AddTransient<ICarService, CarService>(); app.UseSoapEndpoint<ICarService>("/dict/Car.asmx", new SoapEncoderOptions());

and Timer. as HostedService
builder.Services.AddSingleton<BatchTimerService>(); builder.Services.AddHostedService(sp => sp.GetRequiredService<BatchTimerService>());
And I have strange situation when Timer doesn't start until one of methods is called.
I don't know, but maybe it's normal situation. Because it's my first SOAP project.

[ShelestSergey]

Forgot to say, that this issue is only when I start service via IIS.
When I start exe manually, everything's fine.

[ShelestSergey]

    public Task StartAsync(CancellationToken stoppingToken)
    {
        _logger.LogInformation("{Service} started.", nameof(RefAssignmentTimerService));

        _version = settings.Value.Version.Assignment;
        _timer = new Timer(async state => await DoWork(), null, TimeSpan.Zero, TimeSpan.FromSeconds(_settings.Value.TimerTimeOut.Assignment));
        return _completedTask;
    }

[andersjonsson]

By default, IIS starts the application pool on demand and then shuts it down after a while if there are no requests.
I think what you're looking for is to set the application pool to "AlwaysRunning"

[ShelestSergey]

@andersjonsson thank you,
But It doesn't work. But I think you right and I have to dig into IIS properties.