large-deployments.md



Large deployments of K8s
For a large scaled deployments, consider the following configuration changes:


Tune ansible settings
for forks and timeout vars to fit large numbers of nodes being deployed.


Override containers' foo_image_repo vars to point to intranet registry.


Override the download_run_once: true and/or download_localhost: true.
See download modes for details.


Adjust the retry_stagger global var as appropriate. It should provide sane
load on a delegate (the first K8s master node) then retrying failed
push or download operations.


Tune parameters for DNS related applications (dnsmasq daemon set, kubedns
replication controller). Those are dns_replicas, dns_cpu_limit,
dns_cpu_requests, dns_memory_limit, dns_memory_requests.
Please note that limits must always be greater than or equal to requests.


For example, when deploying 200 nodes, you may want to run ansible with
--forks=50, --timeout=600 and define the retry_stagger: 60.