Kubernetes Horizontal Pod Autoscaler: Difference between revisions
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=Overview= | =Overview= | ||
Horizontal pod autoscaling is the automatic increase or decrease the number of pod replicas managed by a higher level controller that supports scaling ([[Kubernetes_Deployments#Scaling|deployments]], replica sets, stateful sets) | Horizontal pod autoscaling is the automatic increase or decrease the number of pod replicas managed by a higher level controller that supports scaling ([[Kubernetes_Deployments#Scaling|deployments]], replica sets, stateful sets). The scaling is performed by a horizontal controller and it is controlled by a [[Kubernetes API Resources Concepts#HorizontalPodAutoscaler|horizontal pod autoscaler Kubernetes API resource]]. For an horizontal pod autoscaler to work correctly, a source of metrics, in particular [[Metrics_in_Kubernetes#Resource_Metrics|resource metrics]], must be deployed. The simplest source of resource metrics is the [[Kubernetes Metrics Server|metrics server]]. | ||
=Playground= | =Playground= | ||
{{External|https://github.com/ovidiuf/playground/tree/master/kubernetes/horizontal-pod-autoscaler}} | {{External|https://github.com/ovidiuf/playground/tree/master/kubernetes/horizontal-pod-autoscaler}} | ||
Revision as of 03:07, 7 October 2020
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
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
HPA Manifest
How it Works
A HorizontalPodAutoscaler Kubernetes API resource enables and configures a horizontal pod controller. The controller periodically reads the appropriate metrics API, calculates the number of replicas required to meet the target metric value configured in the HorizontalPodAutoscaler resource, and adjust the "replicas" field on the target pod controller.