Openvswtich agent break the existing data plane as not stable server

[zhaobo]

Current openvswitch agent need to be stronger for more cases.

Please see [1]

This line will clean up all stale ovs flows. Try to think, if there is a case, when the ovs agent restart and try to get its hold device info(rpc to server get them and store into local cache if possible).In this case, we can only get them from server after scan existing ovs bridge. But at this moment, some device info can not be got successful by neutron server not stable/rabbitmq hang. Then this kind devices will failure to sync. The following step is [1], it cleans the previous ovs flow which there maybe some users traffic on that. That means it breaks the existing data plane. This is a terrible situation.

For private cloud providers, when they face the issue online or need to upgrade servers. This kind situation would be very frequency. So once they hit this issue, the effects are quite large.

[1] http://git.openstack.org/cgit/openstack/neutron/tree/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py#n2158

[YAMAMOTO Takashi (yamamoto)]

do you have a concrete idea how to to improve it?

[Rodolfo Alonso (rodolfo-alonso-hernandez)]

Closing this bug for now. Please feel free to reopen it if needed, providing new information.