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Poettering: Rethinking PID 1

Posted May 6, 2010 10:19 UTC (Thu) by hppnq (subscriber, #14462)
In reply to: Poettering: Rethinking PID 1 by mezcalero
Parent article: Poettering: Rethinking PID 1

each time a job is started it is done in ignorance whether it is already running

That's exactly the purpose. Cleverer schedulers would need a timeout to detect a runaway job, and it is not at all clear what should happen when the job times out. Better to let the jobs handle this, as indeed, most probably do.

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Posted May 6, 2010 21:32 UTC (Thu) by mezcalero (guest, #45103) [Link]

Sorry that I have to disappoint you, but no, most cronjobs don't properly check for concurrent execution.

And the problem of runaway jobs is orthogonal to this, as it applies to every job you run in the system. And we already provide the right tools to deal with this (i.e. timeouts, yadda yadda)

Poettering: Rethinking PID 1

Posted May 7, 2010 17:47 UTC (Fri) by hppnq (subscriber, #14462) [Link]

Bit confused here. I think you would agree with me that for cronjobs where it matters that 1) they run at the scheduled time and 2) there is only one running instance, some amount of intelligence in the job itself is what is needed?