The scheduler is just best effort at the moment there's some ways around it.

You could indeed create seperate replication-controllers against labels, such as your aws-zone, and run them seperatly. This flies in the face of having replication-controllers and sucks in my opinion.

The other option is a single replication-controller and have your containers use a resouce that can't be reused, thus ensuring you're scheduled elsewhere. This is hacky.

I suspect it'll be another year before kubernetes is all singing and dancing, but I do like using it.

I know that OpenShift 3, built on kubernetes, supports both affinity and anti-affinity policies (https://access.redhat.com/documentation/en/openshift-enterpr...). I don't know if these are part of kubernetes or part of the extensions custom to OpenShift.

I'm not sure of the current status, but I believe the mechanism would be to label nodes with rack information. You'd then be able to specify anti-affinity constraints based on those labels that would be taken into account by the scheduler.

Edit: browsing issues briefly, I don't think this functionality is available just yet. Discussion of node selectors: https://github.com/kubernetes/kubernetes/issues/341#issuecom... -