Comment 38 for bug 1365473

Ok, so what I have found is a situation when qg- port is added to br-int and assign the VLAN (configuration with int-br-ex and phy-br-ex veth).

The ovs_neutron_agent is in one iteration of rpc_loop processing the deleted port via process_deleted_ports() method, marking the qg- port as dead (ovs flow rule to drop the traffic) and in another iteration, the ovs_neutron_agent is processing the removed port by treat_devices_removed() method.

In first iteration, the port deleting is triggered by port_delete() method:
2015-09-04 14:16:20.337 DEBUG neutron.plugins.ml2.drivers.openvswitch.agent.ovs_neutron_agent [req-e43234b1-633b-404d-92d0-0f844dadb586 admin 0f6c0469ea6e4d95a27782c46021243a] port_delete message processed for port 1c749258-74fb-498b-9a08-1fec6725a1cf from (pid=136030) port_delete /opt/openstack/neutron/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py:410

and in second iteration, the device removed is triggered by ovsdb:
2015-09-04 14:16:20.848 DEBUG neutron.agent.linux.ovsdb_monitor [-] Output received from ovsdb monitor: {"data":[["bab86f35-d004-4df6-95c2-0f7432338edb","delete","qg-1c749258-74",49,["map",[["attached-mac","fa:16:3e:99:37:68"],["iface-id","1c749258-74fb-498b-9a08-1fec6725a1cf"],["iface-status","active"]]]]],"headings":["row","action","name","ofport","external_ids"]}
 from (pid=136030) _read_stdout /opt/openstack/neutron/neutron/agent/linux/ovsdb_monitor.py:50

Log:
http://paste.openstack.org/show/445479/

Should this be filed as a bug?