Kubernetes Horizontal Pod Autoscaler

External

• https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/
• https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale-walkthrough/
• https://towardsdatascience.com/kubernetes-hpa-with-custom-metrics-from-prometheus-9ffc201991e
• https://github.com/kubernetes/community/blob/master/contributors/design-proposals/instrumentation/custom-metrics-api.md

Internal

• Kubernetes Autoscaling Concepts
• Metrics in Kubernetes

Overview

Horizontal pod autoscaling is the automatic increase or decrease the number of pod replicas managed by a higher level controller that supports scaling (deployments, replica sets, stateful sets).. The scaling is performed by a horizontal controller and it is controlled by a horizontal pod autoscaler Kubernetes API resource. For an horizontal pod autoscaler to work correctly, a source of metrics, in particular resource metrics, must be deployed. The simplest source of resource metrics is the metrics server.

Playground

https://github.com/ovidiuf/playground/tree/master/kubernetes/horizontal-pod-autoscaler

HPA Manifest

Horizontal Pod Autoscaler Manifest

Architecture

A HorizontalPodAutoscaler Kubernetes API resource enables and configures a horizontal pod controller. The controller periodically reads the appropriate metrics API.

Operations

• Create an autoscaler.