For a scalable, stateless application, Kubernetes recommends using aDeploymentbecause it provides a higher-level, declarative management layer over Pods. A Deployment doesn’t just “run replicas”; it manages the entire lifecycle of rolling out new versions, scaling up/down, and recovering from failures by continuously reconciling the current cluster state to the desired state you define. Under the hood, a Deployment typically creates and manages aReplicaSet, and that ReplicaSet ensures a specified number of Pod replicas are running at all times. This layering is the key: you get ReplicaSet’s self-healing replica maintenance plus Deployment’s rollout/rollback strategies and revision history.
Why not the other options? APodis the smallest deployable unit, but it’s not a scalable controller—if a Pod dies, nothing automatically replaces it unless a controller owns it. AReplicaSetcan maintain N replicas, but it does not provide the full rollout orchestration (rolling updates, pause/resume, rollbacks, and revision tracking) that you typically want for stateless apps that ship frequent releases. ADaemonSetis for node-scoped workloads (one Pod per node or subset of nodes), like log shippers or node agents, not for “scale by replicas.”
For stateless applications, the Deployment model is especially appropriate because individual replicas are interchangeable; the application does not require stable network identities or persistent storage per replica. Kubernetes can freely replace or reschedule Pods to maintain availability. Deployment strategies (like RollingUpdate) allow you to upgrade without downtime by gradually replacing old replicas with new ones while keeping the Service endpoints healthy. That combination—declarative desired state, self-healing, andcontrolled updates—makesDeploymentthe recommended object for scalable stateless workloads.
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