Comment 1 for bug 1837995

Looks like this is the request:

2019-07-26 16:12:57.213 8682 INFO nova.osapi_compute.wsgi.server [req-cbea9542-ecce-42fd-b660-fc5f996ea3c3 1e45ea9a7d5647a6a938c2ac027822f2 85dd8936d21b46a8878ed59678c7ad9a - default default] c5f::e2 "GET /v2.1/85dd8936d21b46a8878ed59678c7ad9a/os-simple-tenant-usage/85dd8936d21b46a8878ed59678c7ad9a?start=2019-06-28T08:12:56.417129&end=2019-07-27T08:12:56.417129 HTTP/1.1" status: 500 len: 641 time: 0.3035989

I then see this in the stacktrace:

2019-07-26 16:12:57.211 8682 ERROR nova.api.openstack.wsgi File "/usr/lib/python2.7/site-packages/nova/api/openstack/compute/simple_tenant_usage.py", line 291, in show

which should be this API:

https://docs.openstack.org/api-ref/compute/?expanded=#show-usage-statistics-for-tenant

it looks like the error is on trying to lazy-load an instance.flavor:

https://github.com/openstack/nova/blob/25e222c68a75f321015f655e9ad6a25365c86b9d/nova/api/openstack/compute/simple_tenant_usage.py#L155

It looks like the issue is probably that in this method that gets the instances from all cells:

https://github.com/openstack/nova/blob/25e222c68a75f321015f655e9ad6a25365c86b9d/nova/api/openstack/compute/simple_tenant_usage.py#L109

It's not storing the cell targeted context on the instance objects so trying to lazy load the flavor data from the cell fails. But why would it try to lazy-load the flavor since we are joining the flavor when we pull the instance from the DB:

https://github.com/openstack/nova/blob/25e222c68a75f321015f655e9ad6a25365c86b9d/nova/api/openstack/compute/simple_tenant_usage.py#L119

So that doesn't make much sense. I would have to try and recreate this in a devstack environment.