Comment 16 for bug 1892904

After some discussion in #openstack-charms the issue is pointing at db connection records that get created for nova cells. e.g. the nova-manage commands seem to create db records for the cell's db connection: https://docs.openstack.org/nova/latest/user/cells.html#setup-of-cells-v2

Michael says to run the same as before and then test via horizon and watch the nova-api-wsgi logs. Then hop into nova_api db and look at the cell_mappings table.