Every DNS request for external domains turns into 10 if you don't explicitly configure FQDNs (dot at the end). This is because in the default configuration the resolver runs with ndots 5 to search all the possible internal Kubernetes and cloud-provider names. Then you have lookups for IPv4 and IPv6 in parallel. So for every external name you look up, you storm the upstream DNS with 10 requests for non existing domains.

Furthermore, the current default DNS service in Kubernetes doesn't have any kind of caching for these kinds of lookups (especially not NXDOMAIN) enabled.

But like I said, this is one of the first issues you hit running Kubernetes on Amazon. It is widely known and can easily be fixed by scaling up some more instances, changing ndots settings, using FQDNs or configuring caching. There is no way that this was the issue, it is plastered all over the internet, the logs are clear and the fixes can be implemented in minutes.

It also doesn't go down completely, the rate-limiter is packets/s on the interface.