Hi All: As [1], [2] shows, at the last stage in VM migration, it will call unplug_vifs(), and then migrate_instance_finish(), in which update_port will be called immediately. I think the two steps should be executed without no disturb., but in my test, there is at least 3 seconds between unplug vif and update_port. As I want to do something with my controller at the two points, so I have tested it many times, and the lasting time remains about 3s. Any comment will be appreciate! Thanks! [1] http://paste.openstack.org/show/198298/ [2] http://paste.openstack.org/show/568983/ -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20160908/8666b895/attachment.html>