Node and OS requirements

Realtime Scheduling

The cluster SHOULD run a kernel configured without CONFIG_RT_GROUP_SCHED. The cluster MUST run with a kernel configured without CONFIG_RT_GROUP_SCHED or with the kernel.sched_rt_runtime_us sysctl set to -1.

Setting the kernel.sched_rt_runtime_us sysctl to -1 is NOT RECOMMENDED for production use.

For more discussion on this see issue #121.

While docker supports using realtime features on systems with CONFIG_RT_GROUP_SCHED and a non--1 value for kernel.sched_rt_runtime_us, Kubernetes does currently not support that. Once support for that lands, we may increase our k8s version requirements in favour of this requirement.

Hostname and Kubernetes Node name

The hostname (including the domain part) of each node (as reported by hostname -f) MUST be the same as the name of the node object in kubernetes for the respective node.