Neutron might use robust quota enforcement

[Salvatore Orlando]

Neutron can allow exceeding the quota in certain cases. Some investigation revealed that quotas in Neutron are subject to a race where parallel requests can each check quota and find there is just enough left to fulfill its individual request.

Neutron has no concept of reservation and optimistically assumes that a resource count before performing a request is all that's needed.

Also, it does not take into account at all that API operations might create resources as a side effect, and that resources can be created even from RPC calls.

The goal of this RFE is to ensure quota enforcement is done in a decent way in Neutron.
Yeah, even quota management is pretty terrible, but let's start with quota enforcement

Oh... by the way, the patches are already under review [1]

Note: I am filing this RFE as the patches [1] did not land by the liberty-1 deadline and I failed to resubmit the already approved Kilo spec [2] because I'm an indolent procrastinator.

[1] https://review.openstack.org/#/q/status:open+project:openstack/neutron+branch:master+topic:bp/better-quotas,n,z
[2] http://specs.openstack.org/openstack/neutron-specs/specs/kilo-backlog/better-quotas.html