What is the primary purpose of the Cluster Autoscaler in Kubernetes?

What is the primary purpose of the Cluster Autoscaler in Kubernetes?

• A. It automatically adjusts the size of a Kubernetes Cluster based on the workload
• B. It scales the number of replicas for an application
• C. It scales the resource requests and limits of a pod
• D. It runs in response to events

Answer: (A)

Cluster Autoscaler automatically adjusts the number of nodes in a Kubernetes cluster based on demand. When workloads cause pods to stay pending because there aren’t enough CPU or memory resources, the autoscaler adds nodes through the cloud provider so those pods can be scheduled. Conversely, when nodes are underutilized, it can remove idle nodes to save costs. This is about scaling the cluster’s compute resources, not the applications themselves. This differs from scaling the number of pod replicas, which is handled by the Horizontal Pod Autoscaler, and from changing pod resource requests or limits, which are defined per pod. The autoscaler focuses on the pool of nodes that run the pods, resizing the cluster as needed to meet demand.

Cluster Autoscaler automatically adjusts the number of nodes in a Kubernetes cluster based on demand. When workloads cause pods to stay pending because there aren’t enough CPU or memory resources, the autoscaler adds nodes through the cloud provider so those pods can be scheduled. Conversely, when nodes are underutilized, it can remove idle nodes to save costs. This is about scaling the cluster’s compute resources, not the applications themselves.

This differs from scaling the number of pod replicas, which is handled by the Horizontal Pod Autoscaler, and from changing pod resource requests or limits, which are defined per pod. The autoscaler focuses on the pool of nodes that run the pods, resizing the cluster as needed to meet demand.