aurora-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Bill Farner <>
Subject Re: Bug in Preemptor?
Date Sun, 14 Sep 2014 15:49:47 GMT
Thanks for raising the concern!

> Unfortunately, it seems the preemptor cannot handle constraints

Sounds like you are saying the Preemptor is only matching resources and not

I'm on a phone, so I may have missed something, but my read is that the
preemptor lets SchedulingFilter.filter deal with satisfying constraints.
 If the SchedulingFilter finds a constraint violation with the scheduling
proposal, it flags that with a Veto.

On Sunday, September 14, 2014, Stephan Erb <>

> Hi together,
> I was scrolling through and noticed that tasks might be
> preempted unnecessarily.
> If I am not mistaken, the code works as follows:
>     for slave in slaves:
>       while SchedulingFilter.filter is still yielding vetos:
>         add preemptable task of slave to list toPreemptTasks
>       if toPreemptTasks has some tasks:
>         preempt
>         return
> SchedulingFilter is checking for available resources and constraints.
> Unfortunately, it seems the preemptor cannot handle constraints: It may
> drain an entire slave trying to make room for a new task. However, if
> this task has a constraint which prevents it from being scheduled on
> this slave at all, then the other tasks are preempted unnecessarily.
> Is my analysis correct here?
> Best Regards,
> Stephan


  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message