Hangfire

Hangfire is an open-source library for ASP.NET and ASP.NET Core that allows you to run background tasks in your application. It supports a variety of job types, including:

• Fire-and-Forget Jobs: Execute a job only once immediately after it is created.

• Delayed Jobs: Execute a job after a specified delay.

• Recurring Jobs: Execute a job at specified intervals, such as daily or weekly.

• Continuations: Execute a job only after a parent job has completed.

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• Simplicity: Hangfire is easy to set up and integrate with ASP.NET and ASP.NET Core applications.

• Reliability: It guarantees that jobs will be executed even if the application crashes or is restarted.

• Scalability: Supports horizontal scaling, allowing you to distribute jobs across multiple servers.

• Dashboard: Provides a built-in dashboard for monitoring and managing jobs.

• Flexible Storage: Supports various storage options like SQL Server, Redis, MongoDB, and LiteDB.

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1. Install Hangfire: Add the necessary NuGet packages to your project:

   Install-Package Hangfire.AspNetCore
   Install-Package Hangfire.LiteDB

2. Configure Hangfire: In your Program.cs file, configure Hangfire to use LiteDB for storage:

   using Hangfire;
   using Hangfire.LiteDB;
   
   var builder = WebApplication.CreateBuilder(args);
   
   // Add services to the container.
   builder.Services.AddHangfire(configuration => {
       configuration.UseLiteDbStorage("litedb.db");
   });
   builder.Services.AddHangfireServer();
   
   var app = builder.Build();
   
   // Configure the HTTP request pipeline.
   app.UseHangfireDashboard("/cron");
   app.MapControllers();
   
   app.Run();

3. Creating Recurring Jobs: Add a recurring job that runs at specified intervals using a cron expression:

   RecurringJob.AddOrUpdate("my-recurring-job", () => Console.WriteLine("Recurring job!"), Cron.Daily);

4. Updating Job Schedules: Update the schedule of an existing recurring job:

   RecurringJob.AddOrUpdate("my-recurring-job", () => Console.WriteLine("Updated recurring job!"), Cron.Hourly);

5. Removing Jobs: Remove a specific recurring job:

   RecurringJob.RemoveIfExists("my-recurring-job");

   Remove all recurring jobs:

   public void RemoveAllRecurringJobs()
   {
       var recurringJobs = JobStorage.Current.GetConnection().GetRecurringJobs();
       foreach (var job in recurringJobs)
       {
           RecurringJob.RemoveIfExists(job.Id);
       }
   }

6. Restarting Hangfire Service: Restart the Hangfire service programmatically by stopping and starting the background job server:

   public class HangfireServiceManager
   {
       private readonly IBackgroundProcessingServer _backgroundProcessingServer;
   
       public HangfireServiceManager(IBackgroundProcessingServer backgroundProcessingServer)
       {
           _backgroundProcessingServer = backgroundProcessingServer;
       }
   
       public void RestartService()
       {
           _backgroundProcessingServer.Dispose(); // Stop the server
           // Optionally, wait a bit before starting it again
           GlobalConfiguration.Configuration.UseLiteDbStorage("litedb.db");
           JobStorage.Current = new LiteDbStorage("litedb.db");
           var backgroundJobServer = new BackgroundJobServer(); // Start the server again
       }
   }

Example Controller

Here’s an example of a controller that manages recurring jobs and Hangfire service operations:

using Microsoft.AspNetCore.Mvc;
using Hangfire;

[ApiController]
[Route("api/[controller]")]
public class JobController : ControllerBase
{
    [HttpGet("add-recurring-job")]
    public IActionResult AddRecurringJob()
    {
        RecurringJob.AddOrUpdate("my-recurring-job", () => Console.WriteLine("Recurring job!"), Cron.Daily);
        return Ok();
    }

    [HttpGet("update-recurring-job")]
    public IActionResult UpdateRecurringJob()
    {
        RecurringJob.AddOrUpdate("my-recurring-job", () => Console.WriteLine("Updated recurring job!"), Cron.Hourly);
        return Ok();
    }

    [HttpGet("remove-recurring-job")]
    public IActionResult RemoveRecurringJob()
    {
        RecurringJob.RemoveIfExists("my-recurring-job");
        return Ok();
    }

    [HttpGet("remove-all-recurring-jobs")]
    public IActionResult RemoveAllRecurringJobs()
    {
        var recurringJobs = JobStorage.Current.GetConnection().GetRecurringJobs();
        foreach (var job in recurringJobs)
        {
            RecurringJob.RemoveIfExists(job.Id);
        }
        return Ok();
    }

    [HttpPost("restart-service")]
    public IActionResult RestartService()
    {
        // Assuming you have implemented the HangfireServiceManager as described
        var manager = new HangfireServiceManager(new BackgroundJobServer());
        manager.RestartService();
        return Ok("Service restarted");
    }
}