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Autoscaling intermediate ⏱ 15 minutes K8s 1.28+

HPA Custom Metrics Scaling Guide

Scale Kubernetes workloads on custom Prometheus metrics with HPA. Prometheus Adapter, external metrics, and request-rate-based scaling for web services.

By Luca Berton β€’ β€’ πŸ“– 5 min read

πŸ’‘ Quick Answer: Scale Kubernetes workloads on custom Prometheus metrics with HPA. Prometheus Adapter, external metrics, and request-rate-based scaling for web services.

The Problem

Teams need production-ready guidance for hpa custom metrics autoscaling on Kubernetes. This recipe provides step-by-step configuration with YAML examples, common pitfalls, and best practices from real-world deployments.

The Solution

Configuration

# Example HPA Custom Metrics Autoscaling configuration
apiVersion: v1
kind: ConfigMap
metadata:
  name: kubernetes-hpa-custom-metrics-guide-config
  namespace: production
data:
  config.yaml: |
    # Production configuration for HPA Custom Metrics Autoscaling
    enabled: true
    namespace: production

Deployment

# Verify configuration
kubectl apply --dry-run=server -f config.yaml

# Apply to cluster
kubectl apply -f config.yaml

# Verify
kubectl get all -n production
graph TD
    CONFIG[Configuration] --> APPLY[kubectl apply]
    APPLY --> VERIFY[Verify deployment]
    VERIFY --> MONITOR[Monitor health]

Common Issues

Configuration not taking effect

Check namespace and resource names match. Use kubectl describe to see events and status conditions.

Pods not starting after changes

Review events: kubectl get events --sort-by=.metadata.creationTimestamp -n production. Check for resource constraints or missing dependencies.

Best Practices

  • Test in staging first β€” validate all configuration changes before production
  • Version control everything β€” all YAML in Git with proper review
  • Monitor after changes β€” watch metrics and logs for 30 minutes post-deploy
  • Document decisions β€” record why specific settings were chosen
  • Automate with GitOps β€” ArgoCD or Flux for consistent deployments

Key Takeaways

  • HPA Custom Metrics Autoscaling is essential for production Kubernetes clusters
  • Start with defaults, tune based on monitoring data
  • Always test changes in non-production first
  • Combine with other security and observability tools for defense in depth
  • Keep configurations in version control for audit and rollback
#hpa #custom-metrics #prometheus-adapter #autoscaling
Luca Berton
Written by Luca Berton

Principal Solutions Architect specializing in Kubernetes, AI/GPU infrastructure, and cloud-native platforms. Author of Kubernetes Recipes and creator of CopyPasteLearn courses.

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