I think you might be a bit misinformed and referring to a much older version of kubernetes. I say this as someone who has used (and deployed) Mesos for the past few years and is currently working on Kubernetes. Kubernetes has pluggable schedulers[1], but unlike Mesos, which requires a scheduler as part of a framework, there is a default Kubernetes scheduler[2]

A kubernetes scheduler is akin to a mesos framework sans the executor and how you interact with them. There is a single way to interact with schedulers in k8s (via the apiserver) and there is a default "executor" which is the containerizer (docker/rkt/oci-d/etc). For proof of this, see the etcd[3] operator or prometheus[4] operators. Both etcd and prometheus are stateful services.

    [1] http://kubernetes.io/docs/admin/multiple-schedulers/
    [2] http://kubernetes.io/docs/admin/kube-scheduler/
    [3] https://coreos.com/blog/introducing-the-etcd-operator.html
    [4] https://coreos.com/blog/the-prometheus-operator.html