Comprehensive and Detailed Explanation From Exact Extract:

To scale microservice Pods based on CPU utilization, the Kubernetes Horizontal Pod Autoscaler (HPA) uses the Kubernetes Metrics Server to monitor resource usage and automatically adjusts the number of Pods. However, scaling Pods may require additional nodes if the current node capacity is insufficient.

The Cluster Autoscaler works with EKS managed node groups to add or remove worker nodes based on pending Pod requirements and resource usage.

By deploying both HPA and Cluster Autoscaler, the system can automatically scale Pods and add nodes as necessary, ensuring efficient resource utilization and availability.

Configuring the Cluster Autoscaler with auto-discovery allows it to manage node groups without manual intervention, reducing operational effort.

Option A only scales nodes based on node CPU utilization, not Pods.

Option B uses VPA recommender mode, which only suggests resource changes and does not scale automatically.

Option C involves manual updates and is not automated scaling.Therefore, option D provides the most operationally efficient, fully automated scaling solution.

Reference from AWS Official Documentation:

Kubernetes Horizontal Pod Autoscaler:"HPA automatically scales the number of Pods based on observed CPU utilization or other metrics."(Kubernetes HPA)

Cluster Autoscaler on Amazon EKS:"The Cluster Autoscaler automatically adjusts the size of the Kubernetes cluster when there are Pods that fail to run due to insufficient resources or when nodes in the cluster are underutilized."(AWS EKS Cluster Autoscaler)