Open Stack

On 03/11/2015 08:31 PM, Joe Gordon wrote:
> 
> 
> On Wed, Mar 11, 2015 at 4:07 PM, Ihar Hrachyshka <ihrachys at redhat.com
> <mailto:ihrachys at redhat.com>> wrote:
> 
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>     On 03/11/2015 07:48 PM, Joe Gordon wrote:
>     > Out of sync Quotas ------------------
>     >
>     > https://etherpad.openstack.org/p/PHL-ops-nova-feedback L63
>     >
>     > The quotas code is quite racey (this is kind of a known if you look
>     > at the bug tracker). It was actually marked as a top soft spot
>     > during last fall's bug triage -
>     > http://lists.openstack.org/pipermail/openstack-dev/2014-September/046517.html
>     >
>     >  There is an operator proposed spec for an approach here -
>     > https://review.openstack.org/#/c/161782/
>     >
>     > Action: we should make a solution here a top priority for enhanced
>     > testing and fixing in Liberty. Addressing this would remove a lot
>     > of pain from ops.
>     >
>     >
>     > To help us better track quota bugs I created a quotas tag:
>     >
>     > https://bugs.launchpad.net/nova/+bugs?field.tag=quotas
>     >
>     > Next step is re-triage those bugs: mark fixed bugs as fixed,
>     > deduplicate bugs etc.
> 
>     (Being quite far from nova code, so ignore if not applicable)
> 
>     I would like to note that other services experience races in quota
>     management too. Neutron has a spec approved to land in Kilo-3 that is
>     designed to introduce a new quota enforcement mechanism that is
>     expected to avoid (some of those) races:
> 
>     https://github.com/openstack/neutron-specs/blob/master/specs/kilo/better-quotas.rst
> 
>     I thought you may be interested in looking into it to apply similar
>     ideas to nova.
> 
> 
> Working on a library for this hasn't been ruled out yet. But right now I
> am simply trying to figure out how to reproduce the issue, and nothing else.

Right, I think assuming an architecture change will magically fix this
without scenarios that expose the existing bugs seems overly optimistic.

I think there is a short / medium term test / reproduce question here,
then a longer term question about different architecture.

	-Sean

-- 
Sean Dague
http://dague.net