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

DevFeed: [Kubernetes v1.37: Scheduler Preemption for In-Place Pod Resize (Alpha)](<https://devfeed.tech/articles/kubernetes-v1-37-scheduler-preemption-for-in-place-pod-resize-alpha-4582.md>)

Original publisher: [Read original article](<https://kubernetes.io/blog/2026/09/10/kubernetes-v1-37-scheduler-preemption-for-in-place-pod-resize-alpha/>)

Author: Natasha Sarkar

Published: 2026-09-10T18:30:00Z

Content type: article

Language: en

Sources: [Kubernetes Blog](<https://devfeed.tech/sources/kubernetes-blog.md>)

Topics: [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>), [Containers](<https://devfeed.tech/topics/containers.md>)

Tags: [containers](<https://devfeed.tech/tags/containers.md>), [cpu](<https://devfeed.tech/tags/cpu.md>), [feature](<https://devfeed.tech/tags/feature.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [memory](<https://devfeed.tech/tags/memory.md>), [node](<https://devfeed.tech/tags/node.md>), [resource](<https://devfeed.tech/tags/resource.md>), [scale](<https://devfeed.tech/tags/scale.md>)

## AI overview

Kubernetes v1.37 adds an alpha scheduler-preemption feature for in-place Pod resizes. It can preempt lower-priority workloads to make capacity available for valid, higher-priority resize requests that are deferred on full nodes.

## Source excerpt

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 gap: if a running Pod requested a resource scale-up that exceeded the host node's allocatable headroom, the Kubelet was forced to mark the request as Deferred. The Pod would remain parked in this state indefinitely, waiting for resources on the node to naturally free up. To bridge this scheduling gap, Kubernetes v1.37 introduces scheduler preemption for in-place Pod resize (Alpha), behind the InPlacePodVerticalScalingSchedulerPreemption feature gate. This feature allows the Kubernetes scheduler to actively free up capacity on a fully-utilized node by preempting lower-priority workloads, enabling the pending in-place resizes of critical, higher-priority applications to succeed. The "deferred" resize challenge To understand why this preemption mechanism is needed, it is helpful to look at how Kubernetes handles running Pod resizing. When a user or controller (such as the Vertical Pod Autoscaler) updates the resource requests of an active container, the Kubelet evaluates whether the underlying node has enough spare allocatable capacity to fulfill the increase. If the node's resources are fully utilized and cannot satisfy the new limits, the Kubelet sets the container's resizeStatus (reported in the Pod's status.containerStatuses[]) to Deferred. Unlike an Infeasible resize request (which is immediately rejected because it exceeds physical machine boundaries, namespace limit ranges, or admission quotas) a Deferred status indicates that the request is valid but is temporarily unable t