Kubernetes Cost Optimization: A Practical Guide

The Hidden Cost of Kubernetes

Kubernetes makes deployment easy, but that ease often leads to over-provisioning. We have seen companies waste 40-60% of their cloud spend on unused resources.

Start With Visibility

You cannot optimize what you cannot measure:

Install Resource Monitoring

apiVersion: v1
kind: Pod
metadata:
name: resource-monitor
spec:
containers:
name: app
resources:
requests:
memory: "256Mi"
cpu: "250m"
limits:
memory: "512Mi"
cpu: "500m"

Key Metrics to Track

CPU utilization vs requests

Memory utilization vs requests

Pod restart frequency

Node utilization

Right-Sizing Strategies

1. Use Vertical Pod Autoscaler (VPA)

VPA automatically adjusts resource requests:

apiVersion: autoscaling.k8s.io/v1
kind: VerticalPodAutoscaler
metadata:
name: my-app-vpa
spec:
targetRef:
apiVersion: apps/v1
kind: Deployment
name: my-app
updatePolicy:
updateMode: "Auto"

2. Implement Request Quotas

Prevent teams from over-requesting:

apiVersion: v1
kind: ResourceQuota
metadata:
name: team-quota
spec:
hard:
requests.cpu: "10"
requests.memory: "20Gi"
limits.cpu: "20"
limits.memory: "40Gi"

Spot Instances for Non-Critical Workloads

Save 60-90% on compute:

apiVersion: v1
kind: Pod
metadata:
name: batch-job
spec:
nodeSelector:
cloud.google.com/gke-spot: "true"
tolerations:
key: cloud.google.com/gke-spot
operator: Equal
value: "true"
effect: NoSchedule

Cluster Autoscaler Configuration

Scale nodes based on actual demand:

apiVersion: v1
kind: ConfigMap
metadata:
name: cluster-autoscaler-config
data:
scale-down-delay-after-add: "10m"
scale-down-unneeded-time: "10m"
scale-down-utilization-threshold: "0.5"

Quick Wins Checklist

Set resource requests and limits on all pods

Enable cluster autoscaler

Use spot/preemptible instances for batch jobs

Implement namespace quotas

Review and right-size monthly

Conclusion

Cost optimization is an ongoing process. Start with visibility, implement autoscaling, and review regularly. Small improvements compound into significant savings.