ovs agent failed to continue to process devices if one of them are failed

[zhaobo]

Ovs agent supports l2 extension framework.

But the logic process each device in a single loop[1], if any l2 extensions process a single device and failed with some unforeseeable errors when ext_manager calls l2 extenstion. The error will be catched in out layer and this loop will exit totally, if there still are some devices not process, maybe the rest of devices maybe success, that no reason to skip all of them, so this is the point to be enhanced.

[1] http://git.openstack.org/cgit/openstack/neutron/tree/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py#n1564

[YAMAMOTO Takashi (yamamoto)]

i feel it can somehow contradict with your other point. https://bugs.launchpad.net/neutron/+bug/1783965
it might be safer to avoid making further changes when something bad is happening.
how do you think?