Poor network performance via cilium - is this expected?
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.