this commit https://review.openstack.org/97662 is only add a lock for refresh_cache, but the info_cache contents while periodic task _heal_instance_info_cache running, may be the old dirty one(before attaching), so the new vif/port attached during this periodic task while be lost after this `_heal_instance_info_cache`.
this commit https:/ /review. openstack. org/97662 is only add a lock for refresh_cache, but the info_cache contents while periodic task _heal_instance_ info_cache running, may be the old dirty one(before attaching), so the new vif/port attached during this periodic task while be lost after this `_heal_ instance_ info_cache` .