DevOps Glossary

Kubernetes ReplicaSet is a Kubernetes controller that keeps a specified number of matching Pods running in a cluster, replacing failed or deleted Pods when needed. You define a replica count, such as 3, along with a selector and Pod template; the ReplicaSet watches the cluster and creates or removes Pods until the actual count matches the desired state. ReplicaSets are most often managed by Deployments, which add rolling updates and rollback behavior, so you usually create a Deployment instead of creating a ReplicaSet directly. A ReplicaSet is useful for keeping stateless application replicas available, but it does not manage application updates, persistent data, or advanced release strategies on its own.