On Thu, Feb 2, 2012 at 10:06 PM, Juan Tellez <j...@embrane.com> wrote: > Jesse, > >>>> What's the traffic mixture like when you have this problem with vlans >>>> (i.e. single flow vs. many connections)? If you run a single stream, what >>>> is the ratio of hits to misses on the relevant datapath? > > Our traffic is varied, some very short flows others are long lasting tcp > connections.
If you have many short flows, it's possible that the CPU load you see is simply the result of normal processing. > We are mostly concerned about the long flows dropping lots of packets. When > we see messages as the above ones, can we expect that the vswitch has dropped > packets? I don't really see anything in the information that you've given that indicates OVS is the one dropping packets. > I think the relevant traffic is in the vif*.0 below, which is 1.1%. Can you > explain hit/miss/lost statistic below? Hits are packets processed entirely in the kernel, misses are sent to userspace for flow setup, lost are packets that were queued to userspace but exceeded the queue length. > Kern.log traces are interesting .. they do seem to correlate to some of the > failures we see: > > /var/log/kern.log.9.gz:Oct 2 20:55:58 localhost kernel: vif122.0: draining > TX queue > /var/log/kern.log.9.gz:Oct 2 20:56:00 localhost kernel: vif117.0: draining > TX queue > /var/log/kern.log.9.gz:Oct 2 20:56:00 localhost kernel: vif121.0: draining > TX queue > /var/log/kern.log.9.gz:Oct 2 20:56:02 localhost kernel: vif112.0: draining > TX queue > /var/log/kern.log.9.gz:Oct 2 20:56:05 localhost kernel: vif113.0: draining > TX queue > > Is draining occurring on a regular interval? Those messages are coming from netback, not OVS. Combined with the fact that you see dropped counts going up on the interface itself, it seems that's the likely cause of the problem. Probably something on the guest side is not keeping up but you should talk to the Xen guys. _______________________________________________ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
