Minion
Minion is a modern, testable background job scheduler for .NET applications. Minion will handle running your background job in a reliable way with SQL Server backed storage.
Example of scenarios when you can use Minion:
- Fire web hooks
- Database cleanup
- Creating recurring automated reports
- Batch sending emails
- ... and more
Installation
Minion is available as a NuGet package. You can install it using the NuGet Package Console windows in Visual Studio:
PM> Install-Package Froda.Minion
Usage
To run the server, add the following lines of code:
MinionConfiguration.Configuration.UseSqlStorage("<connection string>");
using (var engine = new BatchEngine())
{
Console.WriteLine("Starting ...");
engine.Start();
Console.ReadKey();
}All jobs need to inherit from Job or Job<TInput>:
public class SimpleJob : Job
{
public override async Task<JobResult> ExecuteAsync()
{
Console.WriteLine("Hello from simple job");
return Finished();
}
}
public class JobWithInput : Job<JobWithInput.Input>
{
public class Input
{
public string Text { get; set; }
}
public override async Task<JobResult> ExecuteAsync(Input input)
{
Console.WriteLine("Hello from job with input: " + input.Text);
return Finished();
}
}To schedule jobs you first need an instance of JobScheduler:
var scheduler = new JobScheduler();Fire-and-forget
The job will be executed as soon as possible.
await scheduler.QueueAsync<SimpleJob>();
var input = new JobWithInput.Input { Text = "This is awesome" };
await scheduler.QueueAsync<JobWithInput, JobWithInput.Input>(input);Scheduled job
The job will execute at the given time.
var date = new Date(2019, 04, 20);
await scheduler.QueueAsync<SimpleJob>(date);
var input = new JobWithInput.Input { Text = "This is awesome" };
await scheduler.QueueAsync<JobWithInput, JobWithInput.Input>(input, date);Recurring jobs
Recurring jobs are scheduled as normal jobs, but need to return a new DueTime:
public class RecurringJob : Job
{
private readonly IDateService _dateService;
public RecurringJob(IDateService dateService) {
_dateService = dateService;
}
public override async Task<JobResult> ExecuteAsync()
{
Console.WriteLine("Hello from recurring job, I will execute every 2 seconds");
return Reschedule(_dateService.GetNow().AddSeconds(2));
}
}Sequence
This will force the jobs to run in sequnce:
var sequence = new Sequence();
sequence.Add<FirstJob>(); //This will run first
sequence.Add<SecondJob>(); //When the FirstJob is finished this will run
await scheduler.QueueAsync(sequence);Set
These jobs will run in parallel if possible:
var set = new Set();
set.Add<FirstJob>();
set.Add<SecondJob>();
await scheduler.QueueAsync(set);More advanced jobs
You can run a set in a sequence, and a sequence in a set:
var sequence = new Sequence();
sequence.Add<FirstJob>(); //This will run first
var set = new Set();
//Second and third job will run in parallel if possible
set.Add<SecondJob>();
set.Add<ThirdJob>();
sequence.Add(set);
sequence.Add<FourthJob>(); //Only when both second and third job is finished, this will run
await scheduler.QueueAsync(sequence);Testing
With the TestingBatchEngine you can simulate your jobs with the ability to time travel.
For an example, if you schedule a job to send an email two days from now, you can fast forward and the batch engine will act as if two days have passed.
[Fact]
public async Task Can_Send_Email() {
//Setup
...
var startDate = new DateTime(2018, 04, 20);
var dateSimulationService = new SimpleDateSimulationService(startDate);
var store = new InMemoryStorage(dateSimulationService);
var eninge = new TestingBatchEngine(store, dateSimulationService);
var scheduler = new JobScheduler(store, dateSimulationService)
await scheduler.QueueAsync<SendEmailJob>(startDate.AddDays(2)); //Schedule job to two days from now
await engine.AdvanceToDateAsync(startDate.AddDays(2)); //Fast forward to two days from now
//Assert
...
}Dependency Injection
To hook up your IoC container to, you need to create a class that inherits from IDependencyResolver:
public class CustomDependencyResolver : IDependencyResolver
{
private readonly IContainer _container;
public CustomDependencyResolver(IContainer container)
{
_container = container;
}
public bool Resolve(Type type, out object resolvedType)
{
resolvedType = _container.Resolve(type);
if(resolvedType == null)
{
return false;
}
return true;
}
}Then you need to pass your resolver to the batch engine:
...
var container = new Container();
var resolver = new CustomDependencyResolver(container);
using(var engine = new BatchEngine(store, resolver)) {
engine.Start();
Console.ReadKey();
}License
Minion goes under The MIT License (MIT).
