Comment 4 for bug 1729621

To be clear, the CoreFilter isn't enabled by default, but Ram and Disk filters are.

The CoreFilter was not deprecated in Ocata:

https://github.com/openstack/nova/blob/stable/ocata/nova/scheduler/filters/core_filter.py

In fact it's still not deprecated:

https://github.com/openstack/nova/blob/master/nova/scheduler/filters/core_filter.py

Because the CachingScheduler will need to rely on it since the CachingScheduler isn't using Placement, and while the CachingScheduler itself was deprecated in Pike:

https://github.com/openstack/nova/commit/d48bba18a7cebc57e63f5b2c5a1e939654de0883

We can't really remove it until we have a migration path for people using the CachingScheduler to move over to the FilterScheduler and populate Placement with the allocations that the FilterScheduler would have been creating in Pike (remember that once all computes are upgraded to Pike+, the ResourceTracker in nova-compute stops reporting allocations to Placement).