Instances are deleted from virsh but still shown as running in Nova after stack deletion is completed

Issue

• Sometimes after a stack deleting is completed, the instances are removed from virsh in the compute nodes but they are still visible in nova:

[root@controller-1 ~(openstack_admin)]# nova list
+--------------------------------------+------+---------+------------+-------------+------------------------------------------------------------------------------------------------------+
| ID                                   | Name | Status  | Task State | Power State | Networks                                                                                             |
+--------------------------------------+------+---------+------------+-------------+------------------------------------------------------------------------------------------------------+
| 4f31d21e-07e5-41fc-8730-6c7b7cdda580 | IB-0 | DELETED | -          | Running     | internal_net=169.254.0.2; external_net=10.10.10.10; management_net=192.168.1.11; fabric_net=169.254.32.6 |
| 9770b4db-7458-445f-8c4e-f3a8783430b7 | IB-1 | DELETED | -          | Running     | internal_net=169.254.0.4; external_net=10.10.10.11; management_net=192.168.1.5; fabric_net=169.254.32.5  |
| 83f9d893-3804-4df1-b343-2920195c8a32 | SB-0 | DELETED | -          | Running     | internal_net=169.254.0.1; external_net=10.10.10.12; management_net=192.168.1.7; fabric_net=169.254.32.1  |
| a3e675da-172a-4d52-9559-6ccddc9815b0 | SB-1 | DELETED | -          | Running     | internal_net=169.254.0.6; external_net=10.10.10.13; management_net=192.168.1.8; fabric_net=169.254.32.4  |
| e115d913-90ba-4635-89ac-39a423c6d97c | SN-1 | DELETED | -          | Running     | management_net=192.168.1.6; internal_net=169.254.0.91                                                |
| f1e1cac7-506c-400f-b818-8b9c841d6ad3 | SN-2 | DELETED | -          | Running     | management_net=192.168.1.9; internal_net=169.254.0.92                                                |
+--------------------------------------+------+---------+------------+-------------+------------------------------------------------------------------------------------------------------+

This results in the inconsistent of nova and virsh. To fix the problem, one has to delete the instances from database.