Update for CoreDNS

Signed-off-by: Alex Ellis (VMware) <[email protected]>

Author: alexellis

docs/architecture/performance.md

@@ -30,10 +30,12 @@ Project tuning:
 * [ ] I have turned off `write_debug` and `read_debug` so that the logs for the function are kept sparse
 * [ ] I am monitoring / collecting logs from the core services and function under test
 * [ ] I am monitoring the system for feedback through Prometheus and / or Grafana - i.e. throughput and 200/500 errors
-* [ ] I am using Kubernetes 1.9 or newer
+* [ ] I am using Kubernetes 1.10 or newer
 * [ ] I am not using Docker Swarm
 * [ ] ~~If running on Docker Swarm I've verified that I am using a proper HEALTHCHECK (read up more on watchdog readme)~~
 
+> A note on DNS: You are likely to get better performance by switching out kube-dns for CoreDNS.
+
 * Watchdog differences
 
 > The [current version of OpenFaaS templates](https://github.com/openfaas/templates) use the original `watchdog` which `forks` processes - a bit like CGI. The newer watchdog [of-watchdog](https://github.com/openfaas-incubator/of-watchdog) is more similar to fastCGI/HTTP and should be used for any benchmarking or performance testing along with one of the newer templates.