(Sorry I usually hate cross-posting, but I've been told to reach both communities) Starting from Kilo, a new DB has been added for Nova that we call "API DB" [1]. It's part of the on-going Cells V2 effort that is not yet to be production-ready. During Liberty, we populated this fresh additional DB by some tables and in Liberty, we began using it. The real production-ish impact is that Nova now needs to have its 2nd DB being created (starting from [2]) Like what was said in the Kilo release notes as an optional thing ([1] again) and was clearly stated in a Mitaka-1 release note [3], people doing Continous Deployment now need to setup their new API DB. Operators still on Liberty and Kilo, you can already prepare to have this new API DB by creating it already. HTH, -Sylvain [1] https://wiki.openstack.org/wiki/ReleaseNotes/Kilo#Cells_v2 [2] https://github.com/openstack/nova/blob/df0fca62cf5324f5b6eae0fed1f88c6c9ed61c71/releasenotes/notes/request-spec-api-db-b9cc6e0624d563c5.yaml [3] https://github.com/openstack/nova/blob/df0fca62cf5324f5b6eae0fed1f88c6c9ed61c71/releasenotes/notes/api-database-now-required-6245f39d36885d1c.yaml