Choosing an Autoscaling Strategy: HPA vs VPA vs KEDA vs Karpenter/Cluster Autoscaler

Choosing an Autoscaling Strategy#

Kubernetes autoscaling operates at two distinct layers: pod-level scaling changes how many pods run or how large they are, while node-level scaling changes how many nodes exist in the cluster to host those pods. Getting the right combination of tools at each layer is the key to a system that responds to demand without wasting resources.

The Two Scaling Layers#

Understanding which layer a tool operates on prevents the most common misconfiguration – expecting pod-level scaling to solve node-level capacity problems, or vice versa.

EKS Setup and Configuration

EKS Setup and Configuration#

Amazon EKS runs the Kubernetes control plane for you – managed etcd, API server, and controller manager across multiple AZs. You are responsible for the worker nodes, networking configuration, and add-ons.

Cluster Creation Methods#

eksctl is the fastest path for a working cluster. It creates the VPC, subnets, NAT gateway, IAM roles, node groups, and kubeconfig in one command:

eksctl create cluster \
  --name my-cluster \
  --region us-east-1 \
  --version 1.31 \
  --nodegroup-name workers \
  --node-type m6i.large \
  --nodes 3 \
  --nodes-min 2 \
  --nodes-max 10 \
  --managed

For repeatable setups, use a ClusterConfig file:

EKS vs AKS vs GKE: Choosing a Managed Kubernetes Provider

EKS vs AKS vs GKE: Choosing a Managed Kubernetes Provider#

All three major managed Kubernetes services run certified, conformant Kubernetes. The differences lie in networking models, identity integration, node management, upgrade experience, cost, and ecosystem strengths. Your choice should be driven by where the rest of your infrastructure lives, your team’s existing expertise, and specific feature requirements.

Feature Comparison#

Control Plane#

GKE has the most polished upgrade experience. Release channels (Rapid, Regular, Stable) provide automatic upgrades with configurable maintenance windows. Surge upgrades handle node pools with minimal disruption. Google invented Kubernetes, and GKE reflects that pedigree in control plane operations.

Kubernetes Cost Optimization: Rightsizing, Resource Efficiency, and Waste Reduction

Kubernetes Cost Optimization#

Most Kubernetes clusters run at 15-30% actual CPU utilization but are billed for the full provisioned capacity. The gap between what you reserve and what you use is pure waste. This article covers the practical workflow for finding and eliminating that waste.

The Cost Problem: Requests vs Actual Usage#

Kubernetes resource requests are the foundation of cost. When a pod requests 4 CPUs, the scheduler reserves 4 CPUs on a node regardless of whether the pod ever uses more than 0.1 CPU. The node is sized (and billed) based on what is reserved, not what is consumed.

Spot Instances and Preemptible Nodes: Running Kubernetes on Discounted Compute

Spot Instances and Preemptible Nodes#

Spot instances are unused cloud capacity sold at a steep discount – typically 60-90% off on-demand pricing. The trade-off: the cloud provider can reclaim them with minimal notice. AWS gives a 2-minute warning, GCP gives 30 seconds, and Azure varies. Running Kubernetes workloads on spot instances is one of the most effective cost reduction strategies available, but it requires architecture that tolerates sudden node loss.