Equivalent of Ihostedservice in asp.net framework for background tasks

Question

I have a restful micro service (web api) in .net 4.6.2 and I want to call a fire and forget function each time after certain endpoints are called to do some database cleanup wor

Answer 1

I guess it's a bit too late, but for someone with the same issue..

Do you know Quartz.NET and Hangfire.io ?

Maybe one of those both could be a very useful tool in your situation. I used it in many applications, and never had any issue.

For example, in Quartz.Net, you first have to create a "job" (it's the term used for this kind of background services) by creating a class implementing IJob interface:

public class HelloJob : IJob
{
    public async Task Execute(IJobExecutionContext context)
    {
        await Console.Out.WriteLineAsync("Greetings from HelloJob!");
    }
}

Then, you have to define when you want to check that job, there are many ways (CRON for example) but we just gonna use a simple schedule here :

        StdSchedulerFactory factory = new StdSchedulerFactory();
        IScheduler scheduler = await factory.GetScheduler();

        await scheduler.Start();

        // define the job
        IJobDetail job = JobBuilder.Create<HelloJob>()
            .WithIdentity("job1", "group1")
            .Build();

        // Trigger the job to run now, and then repeat every 20 seconds
        ITrigger trigger = TriggerBuilder.Create()
            .WithIdentity("trigger1", "group1")
            .StartNow()
            .WithSimpleSchedule(x => x
                .WithIntervalInSeconds(20)
                .RepeatForever())
            .Build();

        // Tell quartz to schedule the job using our trigger, DON'T FORGET THIS ONE
        await scheduler.ScheduleJob(job, trigger);

You are in a micro services architecture based on windows service. You should be able to catch all "graceful" shutdown of your application. In these cases, you have to shutdown properly the Quartz scheduler :

await scheduler.Shutdown();

I personally really like these kinds of approach. It's reusable (you just have to schedule a new job here) and easy to get into that for any developer on your team.

I hope it will help you a bit with your issue.

Answer 2

One of the safest ways to proceed would be to use a Thread. You can fire the thread ans let it run.

If you need the thread to get killed in case the App closed, You can add the isBackground parameter.
Otherwise, the thread should continue to run until its work is finished

Thread backgroundThread = new Thread(() => 
{
    Console.WriteLine("I'll run until the app Stops or I finish working");
    LongRunningJob();
}, IsBackground = true);

Thread foregroundThread = new Thread(() => 
{
    Console.WriteLine("I'll stop when I'm finished");
    LongRunningJob();
}
backgroundThread.Start();
foregroundThread.Start()