autoscaler/vertical-pod-autoscaler/docs/quickstart.md

Quick start

Contents

• Quick start
  • Test your installation
  • Example VPA configuration
  • Troubleshooting

After installation the system is ready to recommend and set resource requests for your pods. In order to use it, you need to insert a Vertical Pod Autoscaler resource for each controller that you want to have automatically computed resource requirements. This will be most commonly a Deployment. There are four modes in which VPAs operate:

• "Auto": VPA assigns resource requests on pod creation as well as updates them on existing pods using the preferred update mechanism. Currently, this is equivalent to "Recreate" (see below). Once restart free ("in-place") update of pod requests is available, it may be used as the preferred update mechanism by the "Auto" mode.
• "Recreate": VPA assigns resource requests on pod creation as well as updates them on existing pods by evicting them when the requested resources differ significantly from the new recommendation (respecting the Pod Disruption Budget, if defined). This mode should be used rarely, only if you need to ensure that the pods are restarted whenever the resource request changes. Otherwise, prefer the "Auto" mode which may take advantage of restart-free updates once they are available.
• "Initial": VPA only assigns resource requests on pod creation and never changes them later.
• "Off": VPA does not automatically change the resource requirements of the pods. The recommendations are calculated and can be inspected in the VPA object.

Test your installation

A simple way to check if Vertical Pod Autoscaler is fully operational in your cluster is to create a sample deployment and a corresponding VPA config:

kubectl create -f examples/hamster.yaml

The above command creates a deployment with two pods, each running a single container that requests 100 millicores and tries to utilize slightly above 500 millicores. The command also creates a VPA config pointing at the deployment. VPA will observe the behaviour of the pods, and after about 5 minutes, they should get updated with a higher CPU request (note that VPA does not modify the template in the deployment, but the actual requests of the pods are updated). To see VPA config and current recommended resource requests run:

kubectl describe vpa

Note: if your cluster has little free capacity these pods may be unable to schedule. You may need to add more nodes or adjust examples/hamster.yaml to use less CPU.

Example VPA configuration

apiVersion: autoscaling.k8s.io/v1
kind: VerticalPodAutoscaler
metadata:
  name: my-app-vpa
spec:
  targetRef:
    apiVersion: "apps/v1"
    kind:       Deployment
    name:       my-app
  updatePolicy:
    updateMode: "Auto"

Troubleshooting

To diagnose problems with a VPA installation, perform the following steps:

• Check if all system components are running:

kubectl --namespace=kube-system get pods|grep vpa

The above command should list 3 pods (recommender, updater and admission-controller) all in state Running.

• Check if the system components log any errors. For each of the pods returned by the previous command do:

kubectl --namespace=kube-system logs [pod name] | grep -e '^E[0-9]\{4\}'

• Check that the VPA Custom Resource Definition was created:

kubectl get customresourcedefinition | grep verticalpodautoscalers