second based scheduling isn't reliable #49
Description
As I understand it, the scheduler works by setting a timer to go off every second.
The problem with this is that in an async environment, a compute-heavy workload can result in the timer being delayed.
When doing a seconds-based schedule this can mean that the task may never be run as the scheduler checks that the current time = the schedule no. of seconds.
The result is that cron is unreliable for seconds based scheduling and may be unreliable for minutes based scheduling if a very heavy process is run.
Ideally, we need to guarantee that tasks are run, even if they are late.