Serilog flushToDiskInterval doesn't work

[Tabigon]

Reproduction steps:

1. Setup Program.cs like this:
   `public class Program
   {
   public static void Main(string[] args)
   {
   IConfigurationBuilder configBuilder = new ConfigurationBuilder();
   configBuilder.SetBasePath(Directory.GetCurrentDirectory())
   .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);
   IConfiguration config = configBuilder.Build();

        Log.Logger = new LoggerConfiguration()
            .WriteTo.File("Logs/log-{Date}.txt", buffered: true, flushToDiskInterval: TimeSpan.FromSeconds(60))
        .CreateLogger();
   
        CreateWebHostBuilder(args).Build().Run();
    }
   
    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
    WebHost.CreateDefaultBuilder(args)
        .UseSerilog() // Set serilog as the logging provider.
        .UseStartup<Startup>();
   

   }`

2. Get logger via DI in some controller:
   `private ILogger _logger;

    public SampleDataController(ILogger<SampleDataController> logger)
    {
        _logger = logger;
    }`
   

3. Trying to log an event:
   public IEnumerable<WeatherForecast> WeatherForecasts(int startDateIndex) { _logger.LogInformation("Test message"); return null; }

Expected result:
Logs are flushed to disk every minute.

Real result:
Logs are flushed right away as log method called

[nblumhardt]

Hi! How are you determining that the flush is immediate? The flushToDiskInterval setting only specifies when an fsync is forced; .NET and Windows/Linux may decide to flush out writes faster than that.