Re: [HTCondor-users] Possible for user to limit number of jobs per physical machine?

[John M Knoeller <johnkn@xxxxxxxxxxx>]

The problem with trying to use ChildRemoteUser in the job's requirements, is that the job needs to match both
the p-slot, and the d-slot that is created from it.   So you have to express this very carefully or else the job
will get a match, but be unable to claim the d-slot.

The requirements for the job would have to be something like

Requirements = TARGET.DynamicSlot || member(MY.user, TARGET.ChildRemoteUser) )

or 

Requirements = TARGET.DynamicSlot || stringListMember( MY.user, join(",",TARGET.ChildRemoteUser) )

-tj

-----Original Message-----
From: HTCondor-users <htcondor-users-bounces@xxxxxxxxxxx> On Behalf Of Carsten Aulbert
Sent: Thursday, September 10, 2020 10:31 AM
To: HTCondor-Users Mail List <htcondor-users@xxxxxxxxxxx>
Subject: [HTCondor-users] Possible for user to limit number of jobs per physical machine?

Hi all,

a current user has the problem to start a very I/O intensive jobs and
would like to limit himself to one or two jobs per defined slot - as we
currently only define a single slot per physical machine, that should
not be a problem.

However, as we admins do not want to change the nodes' configuration on
a per user basis or that often, especially not if each user only has a
subset of jobs which are that demanding.

Therefore the question, has anyone a recipe how a user could limit
himself to only run a limited number of jobs per node regardless of how
many subslots a partitionable main slots a machine may have?

While browsing around the docs and mailing list archive, the only place
I found where this information may be readily available is the machine
ad "ChildRemoteUser" from the PartitionableSlot. However, given that
this seems to be a stringified list, I do not know if and how this could
be used in the Requirements section of a submit file.[1]

Anyone with an idea?

Cheers

Carsten

[1] While writing this email - thus without testing it so far - I
wondered if it were possible to use any of the predefined functions[2]
in the user's submit file to target only machines where this particular
user has nothing running so far? Or would that in the end lead to a
situation where the Negotiator would propose a match but the node may
refuse the job to run?

[2]
https://htcondor.readthedocs.io/en/latest/misc-concepts/classad-mechanism.html#predefined-functions


-- 
Dr. Carsten Aulbert, Max Planck Institute for Gravitational Physics,
CallinstraÃe 38, 30167 Hannover, Germany
Phone: +49 511 762 17185