Rightsizing Kubernetes Workloads: A Step-by-Step Guide

Introduction

Kubernetes resource requests and limits are the primary lever for controlling compute costs in containerized environments. Yet most organizations over-provision by 40-60%.

Step 1: Establish Baseline Metrics

Before rightsizing, collect at least 14 days of CPU and memory utilization data at the pod level. Use tools like Prometheus with custom recording rules to capture p50, p95, and p99 utilization.

Step 2: Identify Over-Provisioned Workloads

Compare requested resources against actual utilization. Focus on workloads where p95 utilization is below 30% of requested resources. These represent the highest-value optimization targets.

Step 3: Implement Gradual Reduction

Never reduce requests to match exact utilization. Apply a safety margin of 20-30% above p95. Implement changes in staging first, then roll to production with canary deployments.

Step 4: Automate and Monitor

Deploy VPA (Vertical Pod Autoscaler) in recommendation mode initially. Graduate to auto-update mode only after validating recommendations against production behavior for 30 days.