kubernetes-hands-on/15-hpa-vpa/README.md

HPA, VPA

HPA means Horizontal Pod Autoscaler. It automatically scales the number of pods in a replication controller, deployment or replica set based on observed CPU utilization (or, with custom metrics support, on some other application-provided metrics).

Let's take an example with CPU usage:

apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
  name: simple-hpa
spec:
  maxReplicas: 10
  minReplicas: 3
  scaleTargetRef:
    apiVersion: extensions/v1beta1
    kind: Deployment
    name: simple-deployment
targetCPUUtilizationPercentage: 80

• spec: the spec for the HPA
  • maxReplicas: the maximum number of pods running
  • minReplicas: the minimum number of pods running
  • scaleTargetRef: what this HPA targets, here a Deployment named simple-deployment
• targetCPUUtilizationPercentage: the percentage of CPU utilization to cross to activate the HPA