KubeCon + CloudNative North America 2022

K8S 1.25 will aim to default cgroupv2 KEP to GA and many new linux distros are already defaulting to cgroupv2 such as latest versions of Ubuntu, Debian, RHEL, etc. This talk will focus on what is cgroupv2 (new kernel APIs for resource management), what cluster administrations need to be aware of during this transition to cgroupv2, and what new features cgroupv2 in k8s will unlock. Some examples of areas we will cover will be memory throttling, disk latency targets, and pressure monitoring. We will discuss some of the active KEPS in k8s taking advantage of these new capabilities and future work in this space. cgroups underlie how resource management works in k8s and focuses on how to properly reserve, allocate, and isolate finite resources on nodes such as CPU, memory, disk, network, etc. This talk will cover the present and future of resource management in k8s. Starting from use cases, we will look under the hood at how kubelet utilizes the underlying linux kernel cgroups for resource isolation and what will change with cgroupv2. There is widespread confusion in the community - should CPU limits be used or not or do they introduce unintended throttling? We hope to provide clarity around this topic and how cgroupv2 will affect it. We will also look at future work in this area.