On Fri, 2022-10-07 at 13:51 +0100, Brendan Doyle wrote: > Hi Folks, > > Apologies if this is a dumb question I'm not too familiar with the > what goes on between ovn-controller and the kernel OVS flows. > > So ovn-controller is control plane, the OVS flows it get pushed > down to the kernel (the data plane). So I expected that if ovn- > controller > is stopped on a hypervisor that the dataplane flows would persist in > the kernel. > > But what I see is if I have a VM on hypervisor A and a gateway on > hypervisor B. If I stop ovn-controller on hypervisor A then I can > no longer access the VM via the gateway. There is no Geneve > traffic sent to hypervisor A.
Stopping ovn-controller shouldn't flush OVS flows as reported by "ovs- ofctl dump-flows br-int". And if the OVS flows don't get flushed I wouldn't expect data plane flows to get flushed either. There used to be an issue when the new ovn-controller started and flushed some flows before it had completely downloaded the Southbound DB but that's been fixed by: http://patchwork.ozlabs.org/project/ovn/list/?series=314426&archive=both&state=* What version of OVN are you running? Can you dump flows on br-int, then stop ovn-controller, then dump flows again and compare? (use --no-stats to make diffing easier). Dan > > I guess as expected CENTRAL has taken hypervisor A out of the > Southbound DB, regenerated flows and updated hypervisor B. > I thought that the OVS flows might persist in the kernel in > hypervisor A and CENTRAL would use the last known location of the > VM and not regenerate flows and still tunnel from the gateway on B > to A. But I guess not, but it does seem odd that the control plane > going down breaks the data plane. > > Brendan. > > _______________________________________________ > discuss mailing list > disc...@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss _______________________________________________ discuss mailing list disc...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
