[one-users] Open Nebula and Scheduling

[Borja Sotomayor]

Hi,

> a) Open Nebula can interface with a third-party scheduler to schedule
> the standing-up of VM instances or

Yes, it's actually possible to swap out the default scheduler and
replace it with a different scheduler. Have you taken a look at
Haizea? (http://haizea.cs.uchicago.edu/) It is a more advanced
scheduler (supporting advance reservations, queueing, etc.) that can
be used as a scheduling backend with OpenNebula. Although, from what
you've described, it might not meet some of you're needs, it might
help you get a sense for what an alternate scheduler looks like.


> b) It would be possible to extend open nebula to interface with a
> third-party scheduler and which bits of the code base I should be
> interested in for this.

With Haizea, I actually didn't have to make any changes to OpenNebula
itself. Haizea runs as a separate daemon, and basically (1)
periodically probes OpenNebula to ask if there are any new requests to
take care of and (2) calls OpenNebula to
start/stop/suspend/resume/etc. VMs. Some functionality that we're
considering might require writing "hooks" for OpenNebula
(http://opennebula.org/documentation:rel2.0:oned_conf#hook_system),
but that still doesn't require modifying any of OpenNebula's core
code.

In Haizea, users still request the VMs to OpenNebula (and Haizea
decides when/where to schedule them). From what you're describing, it
sounds like you would like users to request jobs to an HPC scheduler,
and then have the HPC scheduler provision resources using OpenNebula,
right? Although this is different from the Haizea use case, my gut
feeling is that this should still be possible as long as the scheduler
provides pre- and post-job hooks so you can create the VMs and do any
necessary cleanup.

Cheers!
--
Borja Sotomayor

 Scientific Writer, Computation Institute
 Lecturer, Department of Computer Science
 University of Chicago
 http://people.cs.uchicago.edu/~borja/

 Community Manager, OpenNebula project
 http://www.opennebula.org/