DevOps Glossary

Kubernetes EndpointSlice is a Kubernetes API object that stores the network endpoints behind a Service in smaller, scalable groups called slices, so components like kube-proxy, CoreDNS, ingress controllers, and service mesh controllers can route traffic to the right Pod IPs and ports. It replaces the older Endpoints object for large Services because one Service can be split across multiple EndpointSlice objects, usually grouped by address type such as IPv4, IPv6, or FQDN, and by protocol and port. When pods are added, removed, or become unready, Kubernetes updates the related EndpointSlices so traffic only goes to healthy backends. This matters most in larger Kubernetes clusters where a Service may point to hundreds or thousands of pods, because smaller slice updates reduce API server load and make service discovery easier to scale. For example, a high-traffic API Service with 800 backend pods may be represented by several EndpointSlices instead of one huge endpoint list, letting routing components watch smaller changes as pods roll during a deployment.