Hangfire Background Worker Manager

Hangfire is an advanced background jobs and worker manager. You can integrate Hangfire with the ABP Framework to use it instead of the default background worker manager.

The major advantage is that you can use the same server farm to manage your Background Jobs and Workers, as well as leverage the advanced scheduling that is available from Hangfire for Recurring Jobs, aka Background Workers.

Installation

It is suggested to use the ABP CLI to install this package.

Using the ABP CLI

Open a command line window in the folder of the project (.csproj file) and type the following command:

abp add-package Volo.Abp.BackgroundWorkers.Hangfire

Manual Installation

If you want to manually install;

1. Add the Volo.Abp.BackgroundWorkers.Hangfire NuGet package to your project:

   Install-Package Volo.Abp.BackgroundWorkers.Hangfire
   

2. Add the AbpBackgroundWorkersHangfireModule to the dependency list of your module:

[DependsOn(
    //...other dependencies
    typeof(AbpBackgroundWorkersHangfireModule) //Add the new module dependency
    )]
public class YourModule : AbpModule
{
}

Hangfire background worker integration provides an adapter HangfirePeriodicBackgroundWorkerAdapter to automatically load any PeriodicBackgroundWorkerBase and AsyncPeriodicBackgroundWorkerBase derived classes as IHangfireBackgroundWorker instances. This allows you to still to easily switch over to use Hangfire as the background manager even you have existing background workers that are based on the default background workers implementation.

Create a Background Worker

HangfireBackgroundWorkerBase is an easy way to create a background worker.

public class MyLogWorker : HangfireBackgroundWorkerBase
{
    public MyLogWorker()
    {
        RecurringJobId = nameof(MyLogWorker);
        CronExpression = Cron.Daily();
    }

    public override Task DoWorkAsync()
    {
        Logger.LogInformation("Executed MyLogWorker..!");
        return Task.CompletedTask;
    }
}

• RecurringJobId Is an optional parameter, see Hangfire document
• CronExpression Is a CRON expression, see CRON expression

You can directly implement the IHangfireBackgroundWorker, but HangfireBackgroundWorkerBase provides some useful properties like Logger.

UnitOfWork

For use with UnitOfWorkAttribute, you need to define an interface for worker:

public interface IMyLogWorker : IHangfireBackgroundWorker
{
}

[ExposeServices(typeof(IMyLogWorker))]
public class MyLogWorker : HangfireBackgroundWorkerBase, IMyLogWorker
{
    public MyLogWorker()
    {
        RecurringJobId = nameof(MyLogWorker);
        CronExpression = Cron.Daily();
    }

    [UnitOfWork]
    public override Task DoWorkAsync()
    {
        Logger.LogInformation("Executed MyLogWorker..!");
        return Task.CompletedTask;
    }
}

Register BackgroundWorkerManager

After creating a background worker class, you should add it to the IBackgroundWorkerManager. The most common place is the OnApplicationInitializationAsync method of your module class:

[DependsOn(typeof(AbpBackgroundWorkersModule))]
public class MyModule : AbpModule
{
    public override async Task OnApplicationInitializationAsync(
        ApplicationInitializationContext context)
    {
        await context.AddBackgroundWorkerAsync<MyLogWorker>();

        //If the interface is defined
        //await context.AddBackgroundWorkerAsync<IMyLogWorker>(); 
    }
}

context.AddBackgroundWorkerAsync(...) is a shortcut extension method for the expression below:

context.ServiceProvider
    .GetRequiredService<IBackgroundWorkerManager>()
    .AddAsync(
        context
            .ServiceProvider
            .GetRequiredService<MyLogWorker>()
    );

So, it resolves the given background worker and adds to the IBackgroundWorkerManager.

While we generally add workers in OnApplicationInitializationAsync, there are no restrictions on that. You can inject IBackgroundWorkerManager anywhere and add workers at runtime. Background worker manager will stop and release all the registered workers when your application is being shut down.