Blog: Kubernetes Blog

The Shift to cgroup v2 in Kubernetes: What You Need to Know

Oct. 6, 2026 » Kubernetes Blog » [Archived Version]

In Linux, cgroups (control groups) are a kernel feature used for managing system resources. Kubernetes uses cgroups to allocate resources like CPU and memory to containers, ensuring that applications run smoothly without interfering with each other. With the release of Kubernetes v1.31, support for v1 cgroup management moved into maintenance mode. Support for v2 cgroup management has been stable since Kubernetes v1.25. Compared with cgroup v1, cgroup v2 provides a single unified hierarchy, a mo…

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Scaling Kubernetes Workloads with Node Swap

Oct. 5, 2026 » Kubernetes Blog » [Archived Version]

Memory is often the first hard limit a Kubernetes cluster hits. Nodes run out of RAM long before they run out of CPU, and the new wave of agentic AI workloads makes this worse. These workloads demand large memory footprints to start up and run untrusted code, then sit idle waiting for the next prompt. That idle but resident memory is expensive, and it caps how many pods a node can hold. This is where swap helps. Kubernetes support for running nodes with swap enabled reached General Availability…

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Spotlight on SIG Apps

Sept. 22, 2026 » Kubernetes Blog » [Archived Version]

As Kubernetes adoption has grown, the conversation has shifted beyond running containers to managing increasingly complex application lifecycles. Modern platforms support stateless web services, stateful databases, batch processing, AI workloads, and platform services. At the same time, they must remain reliable during upgrades, scaling events, and infrastructure failures. Every Kubernetes user relies on SIG Apps, whether they realize it or not. Deployments, StatefulSets, DaemonSets, Jobs, and …

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Kubernetes v1.37: Tracking When a PersistentVolumeClaim Was Last Used (Beta)

Sept. 21, 2026 » Kubernetes Blog » [Archived Version]

Kubernetes v1.37 promotes the PersistentVolumeClaimUnusedSinceTime feature gate to Beta (enabled by default). With this feature, the PersistentVolumeClaim (PVC) protection controller adds an Unused condition to each PVC, telling you whether any running pod currently references it — no custom tooling or cross-referencing required. For the API definition of PVC conditions, see the PersistentVolumeClaim API reference. Read on to learn how the Unused condition works and how to use it. Why track PVC…

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Kubernetes v1.37: Hardening Container Storage with Bind Mount Options and EmptyDir Permissions

Sept. 16, 2026 » Kubernetes Blog » [Archived Version]

Kubernetes v1.37 brings important storage security features: emptyDir permission modes and bind mount options. They help application programmers and security professionals implement rigorous security policies, for example, prohibiting deletion of files across containers or execution of arbitrary binaries from writable volumes, directly in Kubernetes without any complicated circumvention. Linux storage and permission fundamentalsBefore diving into the new Kubernetes features, let us briefly revi…

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Kubernetes v1.37: Pod-Level Resource Managers graduated to Beta

Sept. 15, 2026 » Kubernetes Blog » [Archived Version]

With the release of Kubernetes v1.37, the Pod-Level Resource Managers feature has graduated to Beta status (disabled by default)! First introduced as an Alpha feature in Kubernetes v1.36, this enhancement builds on Pod-Level Resources by equipping Kubelet's Topology Manager, CPU Manager, and Memory Manager to use Pod-level resource declarations (.spec.resources) directly when making hardware placement decisions. Bringing pod-level resources to node managersBefore this feature, obtaining exclusi…

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Kubernetes v1.37: Memory QoS Graduates to Beta

Sept. 14, 2026 » Kubernetes Blog » [Archived Version]

Memory QoS has graduated to Beta in Kubernetes v1.37 and is now enabled by default. On Linux nodes running cgroup v2, the feature uses the memory controller to give the kernel better guidance on how to treat container memory. It was first introduced as Alpha in v1.22, and expanded in v1.36 with tiered memory reservation. This post covers what changed in v1.37, what the Beta promotion means for cluster operators, and how to configure the feature. What changed in v1.37Memory QoS is Beta and enabl…

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Kubernetes Changed Block Tracking API - Beta Differences

Sept. 14, 2026 » Kubernetes Blog » [Archived Version]

Changed Block Tracking (CBT) support for CSI drivers shipped as Alpha in September 2025. With the March 2026 v1.0.0 release of the external-snapshot-metadata project, the feature moved to Beta. If you aren't yet familiar with changed block tracking for storage in Kubernetes, the Alpha announcement covers the motivation, the three primary components (the CSI SnapshotMetadata gRPC service, the SnapshotMetadataService CRD, and the external-snapshot-metadata sidecar), and a walkthrough of how to us…

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Kubernetes v1.37: Native Histograms Graduates to Beta

Sept. 11, 2026 » Kubernetes Blog » [Archived Version]

I'm excited to announce that native histogram support for Kubernetes metrics is graduating to Beta and is enabled by default in Kubernetes v1.37! Native histograms (previously introduced as Alpha in Kubernetes v1.36 under KEP-5808) bring high-resolution, low-cardinality observability to Kubernetes metrics. By adopting Prometheus Native Histograms, Kubernetes components now expose latency and duration metrics with far greater accuracy while significantly reducing telemetry storage and scraping o…

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Kubernetes v1.37: Scheduler Preemption for In-Place Pod Resize (Alpha)

Sept. 10, 2026 » Kubernetes Blog » [Archived Version]

In Kubernetes, resource allocation has historically been a static decision made during a Pod's initial scheduling and placement. With the graduation of the core in-Place Pod resize feature to General Availability in v1.35, application developers and cluster operators gained the powerful ability to dynamically adjust CPU and memory allocations of running containers without incurring disruptive restarts or application downtime. However, in-place resizing introduced a unique resource scheduling ga…

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