Comment 1 for bug 1757207

> su -s /bin/sh -c "nova-manage cell_v2 discover_hosts --verbose" nova
The deleted compute node will be added again as a new node.

That doesn't actually have anything to do with the compute node records getting re-created after you delete the service records.

Are you actually stopping the nova-compute service before you delete the service records via the API? Because if not, there is a periodic task in the nova-compute service that will automatically re-create the compute_nodes records in the database.

See the note in the API reference:

https://developer.openstack.org/api-ref/compute/#delete-compute-service