rapid firing from command line can go over quota

script was to the effect of

for x in range(20):
    os.system('nova boot --flavor 5 --image adsfsadfdsa-fdsafdsf-adasfdsa test_%d &' %x
    x += 1

I think fixing this may require some sort of rearchitecting of how nova does quota management. The idea I have in mind specifically is that the quota check would be modified to also store a "reservation" if quota succeeds. Once the instance (or whatever) is used, the reservation could be ticked over to the in-use count, and if it fails, it can simply be deleted. (Of course, there should also be a synchronization to remove orphaned reservations…) Quota checks would then count not just the existing {instances,cores,ram,etc.} but also the existing reservations; this would be sufficient to prevent oversubscribing quotas this way.

(Of course, there would have to be atomicity constraints on the quota check/reservation create.)

Here are some of my thoughts on how this could be addressed:

http://etherpad.openstack.org/quota-atomicity

Fix proposed to branch: master
Review: https://review.openstack.org/6774

Reviewed: https://review.openstack.org/6774
Committed: http://github.com/openstack/nova/commit/406ff304bb09f144a59448e0e9d2d01160c7d553
Submitter: Jenkins
Branch: master

commit 406ff304bb09f144a59448e0e9d2d01160c7d553
Author: Kevin L. Mitchell <email address hidden>
Date: Fri May 4 19:27:43 2012 -0500

    Rearchitect quota checking to partially fix bug 938317.

    This is a rearchitecting/rewriting of quota handling to correct the
    quota atomicity issues highlighted by bug 938317. Partially implements
    blueprint quota-refactor as well.

    This change is fairly substantial. To make it easier to review, it has been
    broken up into 3 parts. This is the first part.

    Change-Id: I805f5750c08de17487e59fe33fad0bed203188a6

Patch committed builds the infrastructure; a second patch actually uses the infrastructure and fixes this bug.

I believe this should be closed as the new quota system is in and committed :)

Yep. There's still work to do, but this particular bug should be fixed.