Re: [Condor-users] ClassAd for total number of Condor jobs

["Ian Chesal" <ICHESAL@xxxxxxxxxx>]

> It's computationally not that expensive, it's something we've thought
> about (and have even hacked on briefly to experiment with) but we've
> got no firm plans on if, how, or when to support.

For anyone wanting to do dynamic load balancing on a multi-VM'ed machine
this would be really useful. For example, I have a machine with 2 VMs
and total available memory of 2GB. I have two jobs, one that's going to
use 1.5 GB of memory and one that's going to use 0.5 GB of memory. The
only way I could get them to run on the machine is to unbalance the
50/50 resource split between the VMs. But if ClassAds were updated
during negotiation I could say something like this in the requirements
tag for the job:

requirements = ((Target.VirtualMachineID == 1) && ((Target.TotalMemory -
Target.vm2_PredictedMemory) > PredictedMemory)) ||
((Target.VirtualMachineID == 2) && ((Target.TotalMemory -
Target.vm1_PredictedMemory) > PredictedMemory))

That's a quick and dirty example to illustrate the essence of the idea.

- Ian