How To: Prevent a job from overlapping with itself

By default, a job will overlap with itself if its execution time takes longer than the scheduled interval it runs at. For example:

SCHEDULER.every '2s' do
  puts "Going to bed...zzz...."
  sleep(6)
  puts "Ok I'm done"
end

will print:

Going to bed...zzz....
Going to bed...zzz....
Going to bed...zzz....
Going to bed...zzz....
Ok I'm done
Going to bed...zzz....
Ok I'm done

This

You can avoid this behaviour by passing the allow_overlapping: false argument to the SCHEDULER.

SCHEDULER.every '2s', allow_overlapping: false do
  puts "Going to bed...zzz...."
  sleep(6)
  puts "Ok I'm done"
end

Problem solved!