I've been searching for using HangFire as a Windows Service for .NET 6, the official document is like 10 years old. Other samples don't specify how to set up the worker service. Anyway, this is my environment -- I have a web app with api app. The api app is where background jobs will be queued to HangFire, but I'd like the actual processing to be on a different server like an app server. So my goal is to create a windows service to simply run HangFire server and continue to let api app to manage job creations.
I've created a new Worker Service project and here is my code:
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
}
}
As you can see, I do have one recurring job that occurs every hour, on the hour.
Then for the class HangFireWorker, this is what I have:
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);
}
}
So my question is, do I need to do anything in the main worker class? In ExecuteAsync() function? I mean the project works just fine as is right now. I see the server is registered successfully in the dashboard (the api app). It seems odd that I just have an empty worker class.
Any advice is appreciated.
You don't need that empty worker class. Simply doing a call to AddHangfireServer will handle creating a worker.
You can actually see that the server is registered if you open the source of AddHangfireServer:
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 will simply register a BackgroundJobServerHostedService and it will handle everything.
A good strategy to figure stuff like this out is to drill down into the actual source code sometime.
This is also kindof documented on the Hangfire.AspNetCore package's github:
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 elseIn console applications, Windows Service, Azure Worker Role, etc.
using (new BackgroundJobServer()) { Console.WriteLine("Hangfire Server started. Press ENTER to exit..."); Console.ReadLine(); }