[TYPO3-core] RFC #12068: Bug: Scheduler: Improper skipping of running tasks in case multiple execution denied

[Christian Kuhn]

Hey,

Francois Suter wrote:
> Bugtracker references:
> http://bugs.typo3.org/view.php?id=12068
> 
> Branches:
> Trunk
> 
> Problem:
> The Scheduler has a mechanism for preventing multiple concurrent 
> executions of the same task. This is logged into the sys_log table. If a 
> CLI call is running and a new one starts while the previous run is not 
> finished (which happens e.g. with a cron job because it will fork its 
> process if the previous one is not finished), the Scheduler runs into an 
> endless loop and floods the sys_log table.
> 
> Solution:
> The next execution time of task must be calculated when the task is 
> launched and not after it has finished. It must also be calculated when 
> a task is skipped, in order to postpone it to the next execution time in 
> the schedule. This prevents the endless loop.

+1 on reading and testing.

Thanks Francois for the quick patch!
This issue caused quite some hazard to one of our development systems, 
take a look to the bugtracker issue for a story of what happened ;)

Thanks
Christian