dnsperfgo

README

dnsperfgo

A golang client for stress-testing Kubernetes DNS. The client program can be configured to send DNS queries at a custom rate, with intervals in order to mimic bursts of traffic followed by idle time. It also searchpath-expands the hostnames provided as input, along with sending A and AAAA in parallel on Alpine-base image. This attempts to recreate the common issues seen with Kubernetes DNS, especially at scale.

This client can be used to benchmark different DNS solutions.

Metrics

This client pushes up the following metrics:

dns_errors_total - Count of DNS lookup errors(including timeouts). dns_timeouts_total - Count of DNS lookup timeouts. dns_lookups_total - Count of DNS lookups. dns_lookup_latency - Latency distribution of DNS lookups.

Build and Push Image

make push

The project "k8s-staging-perf-tests" can be used for pushing the image used by CI runs.

Spin up a test deployment on an existing cluster

kubectl create -f queries-cm.yaml
kubectl create -f deployment.yaml

Note that the dns client counts NXDOMAIN responses as errors, so the configmap needs to contain names that are expected to resolve. Otherwise, non-zero error metric is expected.