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.