What New Features and ACK Enhancements Arrive with Kubernetes 1.22?

New features in Kubernetes 1.22

PersistentVolume health monitoring – adds a health check controller that reports PV status and integrates with the volume health feature gate.

Memory Quality‑of‑Service (QoS) using cgroups v2 – enables fine‑grained memory limits and burstable QoS guarantees based on the new cgroup hierarchy.

Windows privileged containers via HostProcess containers – allows Windows workloads to run with elevated privileges by mapping the host process namespace.

Workload node swap support (Linux only) – permits pods to request swap memory on nodes that have swap enabled, improving scheduling flexibility for memory‑intensive workloads.

Default seccomp profile for Linux workloads – applies a baseline seccomp profile automatically when none is specified, enhancing container security.

ACK components upgraded for Kubernetes 1.22

Kubernetes control plane (API server, scheduler, controller manager)

etcd data store

CoreDNS DNS service

Container Runtime Interface (CRI) implementation

Container Storage Interface (CSI) drivers

Container Network Interface (CNI) plugins

NVIDIA Container Runtime for GPU workloads

Ingress Controller (including ALB and Nginx variants)

Additional ACK capabilities for Kubernetes 1.22

Observability

Extended APIServer request metrics (e.g., request latency, response codes) are exposed via the /metrics endpoint.

For ACK Pro, ASK Pro, and Edge Pro clusters, core control‑plane components (etcd, kube‑scheduler, kube‑controller‑manager) emit additional Prometheus metrics.

Stability

Enhanced storage‑layer protection reduces the impact of cold‑start operations on etcd by throttling write bursts.

Configurable APIServer rate‑limiting based on request source, verb, or API group helps prevent overload during cluster start‑up.

Performance optimizations

Kubelet in‑place upgrades minimize container restarts by preserving pod state while the kubelet binary is replaced.

KubeProxy now supports Aliyun Linux 2 kernels ≥ 4.19.91‑23 and disables conn_reuse_mode when IPVS mode is enabled, improving load‑balancing stability.

ASK clusters avoid evicting Elastic Container Instance (ECI) pods when a Virtual Node is not ready, reducing unnecessary pod churn.

ACK Pro and Edge Pro schedulers gain gang scheduling, CPU topology awareness, and GPU topology awareness for better placement of tightly coupled workloads.

Upgrade considerations for Kubernetes 1.22

Beta API removal – many APIs that were in beta in earlier releases are removed. Verify that all manifests and controllers use the stable versions before upgrading.

Dockershim deprecation – dockershim was deprecated in 1.20 and will be removed in 1.24. Migrate nodes to containerd (or continue using Docker EE for Windows containers) and complete the runtime transition before moving to 1.24.

PodSecurityPolicy (PSP) deprecation – PSP is deprecated since 1.21 and will be removed in 1.25. Replace PSP with the newer PodSecurity admission controller to enforce security standards.