RecurrentTasks

This lightweight library allows you to run simple background tasks with specified intervals in your ASP.NET application.

Each task is a separate Task, which sleeps in background for a while, wakes up, perform some job and sleeps again.

Ideal, when you don't need to run many/heavy tasks and don't want to use "big" solutions with persistence and other bells and whistles.

Written for NET Core (support for ASP.NET 5 and ASP.NET Core 1.0 and 2.0 is dropped since v6, use v5.0.0 release if you need support for old frameworks).

Main features

• TargetFrameworks: netstandard2.0 and netcoreapp3.1
• Start and Stop your task at any time;
• IHostedService implemented for NET Core 2.0 (and above) app lifetime support
• CancelationToken may be used for Stopping;
• First run (after Start) is delayed at random value (10-30 sec, customizable) to prevent app freeze during statup;
• Run "immediately" (without waiting for next scheduled time);
• Change run interval while running;
• Single-execution-at-a-time: A task already running will wait before running again (timer for "next" run will start only after "current" run completes);
• RunStatus property contains:
  • last/next run times;
  • last run result (success / exception);
  • last success run time;
  • last exception;
  • total failed runs counter.

Usage

1. Create new task class

public class MyFirstTask : IRunnable
{
    private ILogger logger;

    public MyFirstTask(ILogger<MyFirstTask> logger)
    {
        this.logger = logger;
    }
    
    public Task RunAsync(ITask currentTask, IServiceProvider scopeServiceProvider, CancellationToken cancellationToken)
    {
        // Place your code here
    }
}

You can add any parameters to constructor, while they are resolvable from DI container (including scope-lifetime services, because new scope is created for every task run).

By default, new instance of IRunnable is created for every task run, but you may change lifetime in AddTask (see below). Use IServiceProvider passed to RunAsync to obtain scope-wide services if you force your task be singleton.

2. Register and start your task in Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.AddTask<MyFirstTask>(o => o.AutoStart(TimeSpan.FromMinutes(5)));
    ...
}

And voila! Your task will run every 5 minutes. Until your application ends, of course.

AddTask adds your MyFirstTask to DI container with transient lifetime (new instance will be created for every task run). Pass desired lifetime to AddTask() to override:

services.AddTask<MyFirstTask>(
  o => o.AutoStart(TimeSpan.FromMinutes(5)),
  ServiceLifetime.Singleton)`.

Run immediately

Anywhere in you app:

// obtain reference to your task
var myTask = serviceProvider.GetService<ITask<MyFirstTask>>();

// poke it
if (myTask.IsStarted)
{
    myTask.TryRunImmediately();
}

Installation

Use NuGet package RecurrentTasks

Dependencies

• Microsoft.Extensions.DependencyInjection.Abstractions, v2.0.0 (for netstandard2.0) / v3.1.0 (for netcoreapp3.1)
• Microsoft.Extensions.Hosting.Abstractions, v2.0.0 / v3.1.0
• Microsoft.Extensions.Logging.Abstractions, v2.0.0 / v3.1.0

Testing

Tests can be run with dotnet test.