Re: [HTCondor-users] ep custom configuration

[Steffen Grunewald <steffen.grunewald@xxxxxxxxxx>]

Hi Antonio,

On Fri, 2025-04-25 at 13:55:55 +0200, HTCondor Users Mailinglist wrote:
> Dear developers,
> 
> I looking for a specific configuration of the execution points of a cluster
> that I am configuring. The use case is the following: we have big cluster
> for data acquisition that must allow the execution of jobs through condor
> only when it is idle, that is when data acquisition is not running. When the
> data acquisition starts the worker nodes must not run any new jobs. This
> should be dynamic and looking in the documentation here:
> 
> https://htcondor.readthedocs.io/en/latest/admin-manual/ep-policy-configuration.html
> 
> in particular the "START Expression" this is something very similar to the
> behavior that can be obtained with "KeyboardIdle" machine classad. Now the
> question comes, is it possible to have a a custom machine classad like the
> keyboard one that say, given the status of the machine it enables or
> disables the job submission? The state of the machine exposed through the
> machine classad should be custom i.e. if some particular process starts on
> the machine or some other condition happens then I can set
> 
> a START expression like
> 
> START = NewCustomClassAd > 15 * $(MINUTE)
> 
> To me it looks like I can mimic the structure of condor_kbdd and create a
> custom daemon that exposes the before mentioned custom machine classad. But
> I am here to ask you if there is something easier to accomplish this.

At first glance, a STARTD_CRON job/hook (run periodically, detecting the running
task and setting an attribute accordingly) might do what you're looking for?
You may want to keep in mind that it'll take a while for the ClassAd to migrate
and be used for matching _new_ jobs; also the START expression won't affect any 
jobs that are _already running_...

Best,
 Steffen


-- 
Steffen Grunewald, Cluster Administrator
Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
Am Mühlenberg 1 * D-14476 Potsdam-Golm * Germany
~~~
Fon: +49-331-567 7274
Mail: steffen.grunewald(at)aei.mpg.de
~~~