OrphanedObjectError spamming nova-api logs

Issue

• nova-api log spammed with the following traceback every few seconds:

2017-01-27 14:26:58.104 17827 DEBUG nova.objects.instance [req-ef1f1668-954c-4a37-8c0a-916fbc8e034f baa1755a22554800829a2cce918310ac 239bb4abfb61471e94426875b3d11f7d - - -] Lazy-loading `flavor' on Instance uuid <uuid> obj_load_attr /usr/lib/python2.7/site-packages/nova/objects/instance.py:858
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions [req-ef1f1668-954c-4a37-8c0a-916fbc8e034f baa1755a22554800829a2cce918310ac 239bb4abfb61471e94426875b3d11f7d - - -] Unexpected exception in API method
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions Traceback (most recent call last):
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/nova/api/openstack/extensions.py", line 478, in wrapped
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     return f(*args, **kwargs)
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/nova/api/openstack/compute/servers.py", line 280, in detail
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     servers = self._get_servers(req, is_detail=True)
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/nova/api/openstack/compute/servers.py", line 406, in _get_servers
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     response = self._view_builder.detail(req, instance_list)
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/nova/api/openstack/compute/views/servers.py", line 151, in detail
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     return self._list_view(self.show, request, instances, coll_name)
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/nova/api/openstack/compute/views/servers.py", line 163, in _list_view
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     server_list = [func(request, server)["server"] for server in servers]
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/nova/api/openstack/compute/views/servers.py", line 291, in show
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     "flavor": self._get_flavor(request, instance),
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/nova/api/openstack/compute/views/servers.py", line 223, in _get_flavor
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     instance_type = instance.get_flavor()
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/nova/objects/instance.py", line 886, in get_flavor
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     return getattr(self, attr)
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/oslo_versionedobjects/base.py", line 66, in getter
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     self.obj_load_attr(name)
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/nova/objects/instance.py", line 876, in obj_load_attr
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     self._load_flavor()
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/nova/objects/instance.py", line 774, in _load_flavor
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     self.flavor = instance.flavor
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/oslo_versionedobjects/base.py", line 66, in getter
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     self.obj_load_attr(name)
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions   File "/usr/lib/python2.7/site-packages/nova/objects/instance.py", line 853, in obj_load_attr
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions     objtype=self.obj_name())
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions OrphanedObjectError: Cannot call obj_load_attr on orphaned Instance object
2017-01-27 14:26:58.152 17827 ERROR nova.api.openstack.extensions