Comment 4 for bug 1971228

Been looking into this, this is definitely a bug. The issue is because cell conductors still need to be configured with the API database to allow for some upcalls https://docs.openstack.org/nova/latest/admin/cells.html#operations-requiring-upcalls . Unless this doc is out of date?

When api_database is set it'll cause nova-conductor to check all cells service versions.

It has in nova/utils.py
if CONF.api_database.connection is not None:

I think this check needs to be different, I'm not sure though if there is a good way to determine if the conductor is running at api level of cell level. The check for the api_database isn't good enough I think.