Hello again,
I tried sending this to [email protected] first but it bounced. Is
that address no longer available?
I posted to ovs-discuss earlier about performance issues with OVS on
CentOS 7. See
<https://mail.openvswitch.org/pipermail/ovs-discuss/2016-November/043003.html>
It seems we've found the culprit, and it's quite unexpected. Due to some
broadcast in our networks, OVS is at times receiving jumbo packets which
cause the following to appear in dmesg:
[1991029.408139] openvswitch: qvo41ed92a6-50: dropped over-mtu packet:
8982 > 1500
[1991029.765021] openvswitch: qvofc43bfd2-9d: dropped over-mtu packet:
8982 > 1500
[1991031.021320] openvswitch: qvo41ed92a6-50: dropped over-mtu packet:
8982 > 1500
On a host where the serial console speed is set to 115200, these log
messages print out fast enough that no significant harm is done, but on
the hosts where we had these issues, our serial console was
misconfigured and very slow. This seems to have affected OVS enough to
cause network latency.
After fixing the console settings, we're no longer experiencing the
heavy latencies, probably because it's now logging fast enough not to
trigger bad behaviour...
Is there perhaps a way to avoid this issue altogether?
--
Jarkko Oranen
_______________________________________________
discuss mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
