Task Scheduler in C# (.NET): Quartz.NET, Hangfire, Coravel

Task Scheduler in C# (.NET): Overview and Examples

In modern C# (.NET) development, there is often a need to execute code on a schedule: send email newsletters, update cache, archive logs, or run ETL processes. Specialized libraries — Job Schedulers — exist for this purpose. In this article, we will review three popular solutions: Quartz.NET, Hangfire, and Coravel, and provide examples of their usage.

1. Quartz.NET — Powerful and Flexible Scheduler

Quartz.NET is a port of the popular Java framework Quartz. It supports complex schedules using cron expressions, job persistence in a database, clustering, and triggers.

Installation

dotnet add package Quartz

Example: Simple Job with a Cron Schedule

using Quartz;using Quartz.Impl;

public class HelloJob : IJob{    public async Task Execute(IJobExecutionContext context)    {        Console.WriteLine($"Hello! Time: {DateTime.Now}");    }}

// Scheduler setupISchedulerFactory schedulerFactory = new StdSchedulerFactory();IScheduler scheduler = await schedulerFactory.GetScheduler();

// Define the jobIJobDetail job = JobBuilder.Create<HelloJob>()    .WithIdentity("helloJob", "group1")    .Build();

// Trigger: every 10 secondsITrigger trigger = TriggerBuilder.Create()    .WithIdentity("trigger1", "group1")    .WithCronSchedule("0/10 * * * * ?") // every 10 seconds    .ForJob(job)    .Build();

await scheduler.ScheduleJob(job, trigger);await scheduler.Start();

Features:

• Support for cron expressions (e.g., 0 0 12 * * ? — every day at noon).
• Job storage in ADO.NET (SQL Server, PostgreSQL, MySQL).
• Ability to dynamically create/delete jobs.
• Clustering for fault tolerance.

2. Hangfire — Simplicity and Built-in Dashboard

Hangfire is a library for executing background tasks with minimal configuration. It provides a built-in web dashboard for monitoring, automatic retries on errors, and integration with ASP.NET Core.

Installation

dotnet add package Hangfiredotnet add package Hangfire.SqlServer # for SQL Server storage

Example: Delayed and Recurring Task

using Hangfire;

// Setup in Startup.cspublic void ConfigureServices(IServiceCollection services){    services.AddHangfire(config =>        config.UseSqlServerStorage("connection_string"));    services.AddHangfireServer();}

public void Configure(IApplicationBuilder app){    app.UseHangfireDashboard(); // /hangfire        // Recurring job: every 5 minutes    RecurringJob.AddOrUpdate(        "cleanup-cache",        () => Console.WriteLine("Cleaning cache..."),        "*/5 * * * *");        // Delayed job (after 1 hour)    BackgroundJob.Schedule(        () => SendEmail("user@example.com"),        TimeSpan.FromHours(1));}

public void SendEmail(string email){    Console.WriteLine($"Sending email to {email}");}

Advantages:

• Built-in dashboard (/hangfire) for viewing job status.
• Automatic retries on failures.
• Support for queues (default: Redis or SQL Server).
• Simple integration with ASP.NET Core via DI.

3. Coravel — Lightweight Scheduler for .NET Core

Coravel is a minimalistic library that requires no external dependencies (other than .NET itself). It is ideal for small projects where persistence is not needed.

Installation

dotnet add