Some time ago I asked about handling thousands of services in a Kubernetes cluster:
Can Kubernetes handle thousands of services?
At that time Kubernetes was using env vars and my question was more oriented to that. Now that Kubernetes has a DNS sounds like we don't have the problem with env vars anymore, however the docs still says it won't perform well when handling thousands of services:
https://github.com/GoogleCloudPlatform/kubernetes/blob/master/docs/services.md#shortcomings
Wanted to know if documentation is outdated or if there are still issues to scale Kubernetes to thousands of services.
The shortcoming mentioned in the documentation has not changed, because Kubernetes still uses the same mechanism (iptables and a userspace proxy) for proxying traffic sent to a service IP to the pods backing the service.
However, I don't believe we actually know how bad it is. A team member briefly tried testing it early this year and didn't see any impact, but didn't do anything rigorous to verify. It's possible that it'll work fine at a couple thousand services. If you try it, we'd love to hear how it goes via IRC or email.