.net - HangFire 作为 .NET 6 的 Windows 服务

Question

我一直在寻找使用 HangFire 作为 .NET 6 的 Windows 服务，官方文档已经有 10 年历史了。其他示例未指定如何设置工作人员服务。不管怎样，这是我的环境——我有一个带有 api 应用程序的 Web 应用程序。 api 应用程序是后台作业将在 HangFire 中排队的地方，但我希望实际处理位于不同的服务器上，例如应用程序服务器。所以我的目标是创建一个 Windows 服务来简单地运行 HangFire 服务器并继续让 api 应用程序来管理作业创建。

我创建了一个新的 Worker Service 项目，这是我的代码:

public class Program
{
    public static void Main(string[] args) => CreateHostBuilder(args).Build().Run();

    public static IHostBuilder CreateHostBuilder(string[] args) =>
       Host.CreateDefaultBuilder(args)
           .ConfigureLogging(logging =>
           {
               logging.ClearProviders();
               logging.AddConsole();
               logging.AddEventLog();
           })
           // Essential to run this as a window service
           .UseWindowsService()
           .ConfigureServices(configureServices);

    private static void configureServices(HostBuilderContext context, IServiceCollection services)
    {
        var defaultConnection = context.Configuration.GetConnectionString("DefaultConnection");
        var hangFireConnection = context.Configuration.GetConnectionString("HangFireConnection");
        AppSettings appSettings = context.Configuration.GetSection("AppSettings").Get<AppSettings>();

        services.AddLogging();
        services.AddHangfire(configuration => configuration
            .SetDataCompatibilityLevel(CompatibilityLevel.Version_170)
            .UseSimpleAssemblyNameTypeSerializer()
            .UseRecommendedSerializerSettings()
            .UseSqlServerStorage(hangFireConnection, new SqlServerStorageOptions
            {
                CommandBatchMaxTimeout = TimeSpan.FromMinutes(5),
                SlidingInvisibilityTimeout = TimeSpan.FromMinutes(5),
                QueuePollInterval = TimeSpan.Zero,
                UseRecommendedIsolationLevel = true,
                DisableGlobalLocks = true
            }));
        services.AddHangfireServer();

        services.AddDbContext<PpContext>(options => options.UseSqlServer(defaultConnection), ServiceLifetime.Transient);
        services.AddScoped<ExceptionNotifier>();
        services.AddHostedService<HangFireWorker>();


        JobStorage.Current = new SqlServerStorage(hangFireConnection);
        RecurringJob.AddOrUpdate<ExceptionNotifier>("exception-notification", x => x.NotifyByHour(), "0 * * * *"); //runs every hour on the hour
    }
}

正如您所看到的，我确实有一项每小时都会发生的重复性工作。

然后对于 HangFireWorker 类，这就是我所拥有的:

public class HangFireWorker : BackgroundService
{
    private readonly ILogger<HangFireWorker> _logger;

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

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        //while (!stoppingToken.IsCancellationRequested)
        //{
        //    _logger.LogInformation("Worker running at: {time}", DateTimeOffset.Now);
        //    await Task.Delay(1000, stoppingToken);
        //}


        //there is nothing to do here, hangfire already takes cares of all?
        await Task.Delay(0);
    }
}

所以我的问题是，我需要在主 worker 类(Class)中做任何事情吗？在 ExecuteAsync() 函数中？我的意思是该项目现在运行得很好。我看到服务器在仪表板(api 应用程序)中注册成功。我只有一个空的 worker 类(Class)，这似乎很奇怪。

如有任何建议，我们将不胜感激。

Answer 1

你不需要那个空的 worker 类(Class)。只需调用 AddHangfireServer 即可处理创建工作线程。

打开AddHangfireServer的源码，实际上可以看到服务器已经注册了:

public static IServiceCollection AddHangfireServer(
  [NotNull] this IServiceCollection services,
  [NotNull] Action<IServiceProvider, BackgroundJobServerOptions> optionsAction)
{
  if (services == null)
    throw new ArgumentNullException(nameof (services));
  return optionsAction != null ? HangfireServiceCollectionExtensions.AddHangfireServerInner(services, (JobStorage) null, (IEnumerable<IBackgroundProcess>) null, optionsAction) : throw new ArgumentNullException(nameof (optionsAction));
}

...

private static IServiceCollection AddHangfireServerInner(
  [NotNull] IServiceCollection services,
  [CanBeNull] JobStorage storage,
  [CanBeNull] IEnumerable<IBackgroundProcess> additionalProcesses,
  [NotNull] Action<IServiceProvider, BackgroundJobServerOptions> optionsAction)
{
  services.AddTransient<IHostedService, BackgroundJobServerHostedService>((Func<IServiceProvider, BackgroundJobServerHostedService>) (provider =>
  {
    BackgroundJobServerOptions options = new BackgroundJobServerOptions();
    optionsAction(provider, options);
    return HangfireServiceCollectionExtensions.CreateBackgroundJobServerHostedService(provider, storage, additionalProcesses, options);
  }));
  return services;
}

...

private static BackgroundJobServerHostedService CreateBackgroundJobServerHostedService(
  IServiceProvider provider,
  JobStorage storage,
  IEnumerable<IBackgroundProcess> additionalProcesses,
  BackgroundJobServerOptions options)
{
  HangfireServiceCollectionExtensions.ThrowIfNotConfigured(provider);
  storage = storage ?? provider.GetService<JobStorage>() ?? JobStorage.Current;
  additionalProcesses = additionalProcesses ?? provider.GetServices<IBackgroundProcess>();
  options.Activator = options.Activator ?? provider.GetService<JobActivator>();
  options.FilterProvider = options.FilterProvider ?? provider.GetService<IJobFilterProvider>();
  options.TimeZoneResolver = options.TimeZoneResolver ?? provider.GetService<ITimeZoneResolver>();
  IBackgroundJobFactory factory;
  IBackgroundJobStateChanger stateChanger;
  IBackgroundJobPerformer performer;
  HangfireServiceCollectionExtensions.GetInternalServices(provider, out factory, out stateChanger, out performer);
  IHostApplicationLifetime service = provider.GetService<IHostApplicationLifetime>();
  return new BackgroundJobServerHostedService(storage, options, additionalProcesses, factory, performer, stateChanger, service);
}

...

public class BackgroundJobServerHostedService : IHostedService, IDisposable
{

AddHangfireServer 只需注册一个 BackgroundJobServerHostedService 即可处理所有事情。

解决此类问题的一个好策略是有时深入研究实际的源代码。

这也在 Hangfire.AspNetCore 包的 github 上有记录:

Process background tasks inside a web application…

You can process background tasks in any OWIN-compatible application framework, including ASP.NET MVC, ASP.NET Web API, FubuMvc, Nancy, etc. Forget about AppDomain unloads, Web Garden & Web Farm issues – Hangfire is reliable for web applications from scratch, even on shared hosting.

app.UseHangfireServer(); … or anywhere else

In console applications, Windows Service, Azure Worker Role, etc.

using (new BackgroundJobServer())
{
    Console.WriteLine("Hangfire Server started. Press ENTER to exit...");
    Console.ReadLine();
}

https://github.com/HangfireIO/Hangfire