Re: [Condor-devel] sorting of groups in negotiation cycle

[Erik Erlandson <eerlands@xxxxxxxxxx>]

On Mon, 2011-05-23 at 13:30 -0500, Dan Bradley wrote:

> > My preferred solution to this would be to re-factor the interaction of
> > HGQ with computation of submitter limits, so that negotiateWithGroup
> > loops over *all* submitters at once, across all groups, but the
> > computation of submitter limits is altered so that it always takes group
> > quotas into account.  This will allow all submitters to negotiate in
> > priority order (which I assume is what happened back in deep fossil time
> > prior to accounting groups), but group quota limits will still be
> > respected.
> 
> Interesting.  It sounds like this needs some careful thinking.  In some 
> uses of the old flat group accounting setup, the user priorities were 
> intentionally wildly different from the quotas.  In other words, the 
> surplus round in which everyone vied for the same pie was ordered quite 
> differently from the ordering during the group negotiation phase.  This 
> is something I wish had been in bold letters in my head when we 
> discussed early versions of the HGQ patch.  I don't know if this same 
> use-case exists in the new system, but if it does, it would be good to 
> think about how it would interact with your proposed change.


I agree, it requires some serious deliberation and group input.   

My reasoning is that the semantic of group quotas is "how many slots are
you allowed" whereas priorities control who gets first crack at slots,
and who can preempt whom.  As far as it goes, those two ideas are
orthogonal.

Of course, priorities *also* have a semantic relating to how many slots
each submitter gets, which muddies the waters:  we now have *two*
features that influence a submitter's slot allocation, although the
current situation where priority operates within group-quota for slot
allocations is reasonably clean.


> surplus round in which everyone vied for the same pie was ordered quite 
> differently from the ordering during the group negotiation phase.  This 
> 

I think the new HGQ logic departs from that significantly -- surplus is
allocated prior to negotiation.  I think these issues surrounding HGQ,
surplus slots and priorities may deserve a pow-wow.