Periodic task for quota reservations expire should move out from scheduler

[Alex Xu]

There periodic task for check expired quota reservation in scheduler https://github.com/openstack/nova/blob/master/nova/scheduler/manager.py#L80

There could be multiple nova schedulers, and quota stuff isn't related to the scheduler, so we should move the quota out of scheduler and find a new way to expire reservations.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/154339

[Alex Xu (xuhj)]

as the discussion in the scheduler meeting http://eavesdrop.openstack.org/meetings/gantt/2015/gantt.2015-03-24-15.00.log.html, this can be defered to L.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Alex Xu (<email address hidden>) on branch: master
Review: https://review.openstack.org/154339

[Yingxin (cyx1231st)]

Change to medium because this bug will block attemps to run multiple scheduler services.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/290302

[Yingxin (cyx1231st)]

If quota expiration needs to be moved out of nova scheduler, I think the best place is nova conductor. However, there are multiple workers of conductor service, should we add periodic tasks to all of the workers? Or we should find another work-around to expire reserved quotas.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/292362

[Sylvain Bauza (sylvain-bauza)]

Having the DB API being called directly by multiple schedulers is not really a problem. That just means that the first scheduler will win for expiring the reservation.

Re-cateogorizing it as Wishilist again.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Alex Xu (<email address hidden>) on branch: master
Review: https://review.openstack.org/154339

[OpenStack Infra (hudson-openstack)]

Change abandoned by Yingxin Cheng (<email address hidden>) on branch: master
Review: https://review.openstack.org/292362
Reason: This work needs a more sophisticated solution, anyone can bring it back :)

[melanie witt (melwitt)]

The periodic task for expiring quota reservations was removed:

https://review.openstack.org/#/c/506822

As of Pike, the quota re-architecting work eliminated use of separate quota usages and reservations.