Open Stack

ML thread: 
http://lists.openstack.org/pipermail/openstack-discuss/2019-June/007135.html

Agreements in the room:

* Check ongoing migration and reject the delete if migration with this
  compute having the source node exists. Let operator confirm the 
migrations
* Cascade delete providers and allocations in placement.
  * in case of evacuated instances this is the right thing to do
  * in any other dangling allocation case nova has the final thrut so 
nova
    has the authority to delete them.
* Document possible ways to reconcile Placement with Nova using
  heal_allocations and eventually the audit command once it's merged.

Cheers,
gibi