How to run a script at random intervals

Question

Hi

I want to write a batch job in c# that runs a task at a random(ish) interval e.g. every hour +/- 20 mins and if no update is needed, then to wait x2 the last time before running again.

What is the best method to do this?

Answer 1

Consider creating a simple application, and kicking it off with the Windows Task Scheduler. The scheduler gives you a lot of control over when and what runs, and it includes time randomization.

EDIT: missed the '2x' part. In the past, I've built Windows Services to do this:

sleep(1x +/- random(20 minutes))
if nothing to do, sleep(2x +/- random(20 minutes))

Answer 2

can just create a timer that pops every so often and runs a method.

example:

Timer ProcessTimer = new Timer(new TimerCallback(ProcessRandomTask), null, 0,Timeout.Infinite);


private void ProcessRandomTask(object data)
{
 //Do work

  lock(ProcessTime)
  {
       //change timer
       ProcessTimer.Change(GetNewTime(), Timeout.Infinite);
  }
}

Answer 3

Everyone else's answers are pretty good, but the only thing I can contribute here is something you should not do. Do not make the application a windows service. I've seen it so many times as an answer to similar problems. That is not what windows services are for.

In my book, windows services are applications/programs that hang in the background to facilitate other programs, or do not require user input to operate. It is not to be used as a method of launching your program at time intervals.

Answer 4

How about logging the timestamp from the last "unnecessary" run to a database/some permanent location? Then, your first line can say:

LastRunWithoutUpdating = GetLastRunWithoutUpdating() // load from file, or db...
if (LastRunWithoutUpdating - CurrentTime < DelayInterval) {
    SkipThisRun(); // sys.exit() or something
}