How to run only one job concurrently?

Question

I have one hangfire server with ~50 recurring jobs. Hangfire setting up on IIS like in this example. Recurring jobs added to hangfire in startup.cs like this:

RecurringJob.AddOrUpdate(job.desctiprion,
            () => job.startJob(), 
            job.cron, 
            TimeZoneInfo.Local);

I need to add new recurring job which running every minute. But there is little chance that this job will be running longer minute. My goal - provide to concurrently work only one exemplar of this job.

What solutions are there? As I understand need something like queue with one thread, but queues don't support thread settings.

Boarish

It's not clear what you're trying to do, 'only one' and 'concurrently' don't really seem to go together. This: provide to concurrently work only one exemplar of this job doesn't make any sense. Can you clarify? – Verenaverene

So you just want to ensure that this job doesn't overlap with itself? – Brenner

I need avoid situation when at one moment more than one instance of this recurring job in processing. Yes I just want to ensure that this job doesn't overlap with itself. For example: first job run in 17:00 and this run take 2 minutes 30 seconds. I need avoid job run in 17:01 and 17:02 but run job in 17:03. I understand that I can use any flag in the database for verification whether the job is now running . But perhaps in Hangfire has a simple and correct solution to this case. – Boarish

Answer 1

You can use DisableConcurrentExecution filter to prevent concurrent executions.

[DisableConcurrentExecution(timeoutInSeconds: 60)]
public void SomeJob()
{
  //method body
}

This filter places a distributed lock in the beginning of a method performance and releases it after it was completed using the IServerFilter interface. The type and method name are being used as a locking resource. Each storage uses its own distributed lock implementation. (read more here)

Thunderhead

Thanks, you answer is very helpfull. Can also be used [AutomaticRetry(Attempts = 0)] for avoid large jobs count in retry. – Boarish

Answer 2

 var worker = new BackgroundWorker();
 worker.DoWork += worker_DoWork;
 worker.RunWorkerCompleted += worker_RunWorkerCompleted;
 private void worker_DoWork(object sender, DoWorkEventArgs e)
 {
        // do your task here
 }
 private void worker_RunWorkerCompleted(object sender,RunWorkerCompletedEventArgs e)
 {

       //Do when completed 
 }

Metonym

Your answer deviates from what OP is asking. He is using hangfire for background job processing. Using BackgroundWorked for this purpose would be a totally different thing. – Thunderhead