Confirmation of Load Balancer Type Used for EKS Control Plane etcd

I apologize, but I don't have specific information about the type of load balancer used for internal communication between the API server and etcd in the Amazon EKS control plane. The sources provided do not contain details about this particular aspect of the EKS architecture.

The available information indicates that the EKS control plane runs in a managed VPC and is designed for high availability and durability. The Kubernetes API server nodes and etcd cluster nodes run in auto-scaling groups across multiple Availability Zones. Both the API servers and etcd servers operate in private subnets.

However, the sources do not specify whether a Classic Load Balancer (CLB) or a Network Load Balancer (NLB) is used for communication between the API server and etcd. They also don't provide information about the reasons for choosing one type of load balancer over another in this context, or about any specific requirements related to gRPC communication, HTTP/2 session persistence, or Raft consensus.

Without more specific and up-to-date information from AWS, I cannot confirm or deny the use of CLB in front of etcd in the current EKS architecture, nor can I provide insights into the technical considerations behind such a choice.

For the most accurate and current information about the internal architecture of the EKS control plane, I recommend consulting the latest AWS documentation or reaching out to AWS support directly.
Sources
EKS Control Plane - Amazon EKS