[openstack-dev] [nova] AggregateMultiTenancyIsolation scheduler filter - bug, or new feature proposal?

Jesse Pretorius jesse.pretorius at gmail.com
Tue Jun 10 07:19:06 UTC 2014

On 9 June 2014 15:18, Belmiro Moreira <moreira.belmiro.email.lists at gmail.com
> wrote:

> I would say that is a documentation bug for the
> “AggregateMultiTenancyIsolation” filter.

Great, thanks. I've logged a bug for this:

> When this was implemented the objective was to schedule only instances
> from specific tenants for those aggregates but not make them exclusive.
> That’s why the work on
> https://blueprints.launchpad.net/nova/+spec/multi-tenancy-isolation-only-aggregates
> started but was left on hold because it was believed
> https://blueprints.launchpad.net/nova/+spec/whole-host-allocation had
> some similarities and eventually could solve the problem in a more generic
> way.
> However p-clouds implementation is marked as “slow progress” and I believe
> there is no active work at the moment.
> Probably is a good time to review the "ProjectsToAggregateFilter" filter
> again. The implementation and reviews are available at
> https://review.openstack.org/#/c/28635/

Agreed. p-clouds is a much greater framework with much deeper and wider
effects. The isolated aggregate which you submitted code for is exactly
what we're looking for and actually what we're using in production today.

I'm proposing that we put together the nova-spec for
but as suggested in my earlier message I think a simpler approach would be
to modify the existing filter to meet our needs by simply using an
additional metadata tag to designate the aggregate as an exclusive one. In
the blueprint you did indicate that you were going to put together a
nova-spec for it, but I couldn't find one in the specs repository - either
merged or WIP.

> One of the problems raised was performance concerns considering the number
> of DB queries required. However this can be documented if people intend to
> enable the filter.

As suggested by Phil Day in https://review.openstack.org/#/c/28635/ there
is now a caching capability (landed in
https://review.openstack.org/#/c/33720/) which reduces the number of DB

Can I suggest that we collaborate on the spec? Perhaps we can discuss this
on IRC? My nick is odyssey4me and I'm in #openstack much of the typical
working day and often in the evenings. My time zone is GMT+2.
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