Re: [HTCondor-users] Condor bug matching with an offline machine

[Todd Tannenbaum <tannenba@xxxxxxxxxxx>]

On 3/2/2017 4:44 AM, Almansour Blanco wrote:
> Hello,
>
> I am using condor 8.4.3 on windows 7 64 bits.
>
> I have a strange bug.
>
> We have some machines that have Wake on LAN  problems in the network.
>
> What happens is, when a job is matched to one of these machines while it
> is offline, it tries to wake it up, which fails of course.
>
> On the next negotiation cycle, the same job can be matched to this
> machine again, and this keeps on happening again and again.
>
> The normal course of action, as far as I know, when a job is matched to
> a machine and it fails, it will always try with another machine, which
> doesn’t seem to be the case here.

What is putting the machine to sleep such that it needs to be waken up 
over the LAN?  Is it some screen saver, or HTCondor itself via the 
HIBERNATE expression in the condor_config file?  I am guessing it is a 
screen saver or some such, as if it was HTCondor itself the machine 
classads would be tagged as offline and would not be matched until 
successfully woken.  So perhaps one idea is to use HTCondor for your 
power management and let it control when to put machines offline; see

  http://htcondor.org/manual/current/3_18Power_Management.html

When a job is matched to a machine and fails, it will not necessarily 
try another machine - it may, as you observe, try the same machine 
again.  This is something we should consider improving in a future 
release, however, for now you can use job policy expressions in your 
job's condor_submit file to achieve this.  For an example of how to do 
this, see the HOWTO recipes, specifically

  https://htcondor-wiki.cs.wisc.edu/index.cgi/wiki?p=AvoidingBlackHoles

Hope the above helps
Todd