Comment 9 for bug 1709594

> Matt thanks for your analysis and suggestions. It works well if we put the api_database in /etc/nova/nova_cell1.conf to allow local conductor accessing API database.

That defeats the purpose of running in superconductor mode, so you might as well run devstack in singleconductor mode as I pointed out. The point of superconductor mode is that the cell is isolated from the top-level API database. See:

https://docs.openstack.org/nova/latest/user/cellsv2_layout.html