Which Kubernetes object maintains a stable set of replica Pods and enables self-healing?

Which Kubernetes object maintains a stable set of replica Pods and enables self-healing?

• A. Service
• B. ConfigMap
• C. ReplicaSet
• D. PersistentVolumeClaim

Answer: (C)

ReplicaSet is responsible for maintaining a stable set of replica Pods. It tracks a desired number of replicas and ensures that many Pods matching its label selector are running at all times. If any Pod fails or is terminated, the ReplicaSet automatically creates a new one to restore the count, providing self-healing for your application. In practice, Deployments manage ReplicaSets, which is why you often interact with Deployments rather than ReplicaSets directly, but the underlying behavior—keeping a fixed number of Pods running and replacing failed ones—comes from the ReplicaSet. A Service, by contrast, provides networking and routing to a set of Pods but does not enforce the number of Pods running. A ConfigMap stores configuration data, not running Pods. A PersistentVolumeClaim requests persistent storage, also not related to maintaining Pod replicas.

ReplicaSet is responsible for maintaining a stable set of replica Pods. It tracks a desired number of replicas and ensures that many Pods matching its label selector are running at all times. If any Pod fails or is terminated, the ReplicaSet automatically creates a new one to restore the count, providing self-healing for your application. In practice, Deployments manage ReplicaSets, which is why you often interact with Deployments rather than ReplicaSets directly, but the underlying behavior—keeping a fixed number of Pods running and replacing failed ones—comes from the ReplicaSet.

A Service, by contrast, provides networking and routing to a set of Pods but does not enforce the number of Pods running. A ConfigMap stores configuration data, not running Pods. A PersistentVolumeClaim requests persistent storage, also not related to maintaining Pod replicas.