I’ve been testing network performance using
iperf3 between pods on our DigitalOcean Kubernetes cluster, to try and aid in debugging issues we have seen around database throughput.
When testing with
hostNetwork: true on the pods, I see an average bitrate of around 1.9GBits/sec between the node IPs. When using the kubernetes network, via Cilium, I only see around 600MBits/sec between the pod IPs.
From reading articles such as on Cilium’s blog I got the impression that the performance disparity should not be anywhere near as much. What is Cilium even actually doing here? :-)
I’m using the docker image mlabbe/iperf3 deployed as a DaemonSet, with the command
iperf3 -c <ip address> -t 100
Kubernetes v1.15.5 - tried on two different DigitalOcean clusters with very similar results.