If two Pods in your cluster want to communicate, and both Pods are actually running on the same node, use _Service Internal Traffic Policy_ to keep network traffic within that node. Avoiding a round trip via the cluster network can help with reliability, performance (network latency and throughput), or cost.

This guide is for application owners who want to build highly available applications, and thus need to understand what types of disruptions can happen to Pods. It is also for cluster administrators who want to perform automated cluster actions, like upgrading and autoscaling clusters. Voluntary and involuntary disruptions Pods do not disappear until someone (a person or a controller) destroys them, or there is an unavoidable hardware or system software error.

The EndpointSlice API is the mechanism that Kubernetes uses to let your Service scale to handle large numbers of backends, and allows the cluster to update its list of healthy backends efficiently.

This document describes ephemeral volumes in Kubernetes. Familiarity with volumes is suggested, in particular PersistentVolumeClaim and PersistentVolume. Some applications need additional storage but don't care whether that data is stored persistently across restarts. For example, caching services are often limited by memory size and can move infrequently used data into storage that is slower than memory with little impact on overall performance. Other applications expect some read-only input data to be present in files, like configuration data or secret keys.

A Kubernetes cluster consists of the components that are a part of the control plane and a set of machines called nodes.

A security context defines privilege and access control settings for a Pod or Container. Security context settings include, but are not limited to: Discretionary Access Control: Permission to access an object, like a file, is based on user ID (UID) and group ID (GID). Security Enhanced Linux (SELinux): Objects are assigned security labels. Running as privileged or unprivileged. Linux Capabilities: Give a process some privileges, but not all the privileges of the root user.

Debugging common containerized application issues.

FEATURE STATE: Kubernetes v1.22 [alpha] This document describes how to run Kubernetes Node components such as kubelet, CRI, OCI, and CNI without root privileges, by using a user namespace. This technique is also known as rootless mode. Note:This document describes how to run Kubernetes Node components (and hence pods) as a non-root user. If you are just looking for how to run a pod as a non-root user, see SecurityContext.

FEATURE STATE: Kubernetes v1.22 [beta] The Kubernetes Memory Manager enables the feature of guaranteed memory (and hugepages) allocation for pods in the Guaranteed QoS class. The Memory Manager employs hint generation protocol to yield the most suitable NUMA affinity for a pod. The Memory Manager feeds the central manager (Topology Manager) with these affinity hints. Based on both the hints and Topology Manager policy, the pod is rejected or admitted to the node.

This page shows you how to configure a Pod to use a PersistentVolumeClaim for storage. Here is a summary of the process: You, as cluster administrator, create a PersistentVolume backed by physical storage. You do not associate the volume with any Pod. You, now taking the role of a developer / cluster user, create a PersistentVolumeClaim that is automatically bound to a suitable PersistentVolume. You create a Pod that uses the above PersistentVolumeClaim for storage.