Vertical pod auto scaling - User Guide for Kubernetes Clusters| Alibaba Cloud Documentation Center

You can deploy the vertical-pod-autoscaler component in a Container Service for Kubernetes (ACK) cluster. vertical-pod-autoscaler is a Vertical Pod Autoscaler (VPA). The VPA enables vertical auto scaling of pods. The VPA automatically sets limits on the resource usage of a cluster based on the pod resource usage. This way, ACK can schedule pods to nodes that have sufficient resources. The VPA also maintains the ratio of the resource request to the resource limit that you specify in the initial container configurations. This topic describes how to use a YAML file to enable vertical pod auto scaling.

Prerequisites

Make sure that the following operations are completed:

An ACK cluster is created and its Kubernetes version is later than 1.12. For more information, see Create an ACK managed cluster.
You are connected to the cluster by using a command-line tool. For more information, see Connect to ACK clusters by using kubectl.
VPA is uninstalled from the cluster. This avoids conflicts when you deploy a new version of the VPA.

Background information

Notice Vertical pod auto scaling is in testing. Use this feature with caution.

You can use the VPA to update the resource configurations of running pods. This feature is in testing. The configuration updates will lead to pod restart and recreation, and the pods may be scheduled to other nodes.
The VPA does not evict the pods that are not managed by replication controllers. For these pods, the Auto mode is equivalent to the Initial mode.
The VPA and the Horizontal Pod Autoscaler (HPA) cannot run at the same time. The HPA monitors the CPU and memory metrics. If the HPA monitors only custom or external resource metrics other than CPU and memory metrics, you can use the VPA in conjunction with the HPA.
The VPA uses an admission webhook as its admission controller. If other admission webhooks exist in the cluster, make sure that the admission webhooks do not conflict with the admission webhook of the VPA. The execution sequence of admission controllers is defined in the parameters of the API server.
The VPA can handle most out of memory (OOM) events, but may fail to handle OOM events in some scenarios.
The VPA performance is not tested in large-scale clusters.
The pod resource request that is modified by the VPA may exceed the upper limit of the actual resources, including node resources, idle resources, and resource quotas. In this case, a pod may enter the Pending state and fail to be scheduled. You can use the cluster autoscaler to mitigate the impact of this issue.
If multiple VPAs monitor the resource usage of a pod at the same time, some undefined behavior may occur.

Install vertical-pod-autoscaler

Run the following command to create a CustomResourceDefinition (CRD) for vertical-pod-autoscaler.

The CRD is used to improve the scalability of ACK clusters. For more information, see Extend the Kubernetes API with CustomResourceDefinitions.

kubectl apply -f crd.yaml

YAML template for clusters whose Kubernetes versions are earlier than 1.22 YAML template for clusters whose Kubernetes versions are 1.22 and later

apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
  name: verticalpodautoscalers.autoscaling.k8s.io
  annotations:
    "api-approved.kubernetes.io": "https://github.com/kubernetes/kubernetes/pull/63797"
spec:
  group: autoscaling.k8s.io
  scope: Namespaced
  names:
    plural: verticalpodautoscalers
    singular: verticalpodautoscaler
    kind: VerticalPodAutoscaler
    shortNames:
      - vpa
  version: v1beta1
  versions:
    - name: v1beta1
      served: false
      storage: false
    - name: v1beta2
      served: true
      storage: true
    - name: v1
      served: true
      storage: false
  validation:
    # openAPIV3Schema is the schema for validating custom objects.
    openAPIV3Schema:
      type: object
      properties:
        spec:
          type: object
          required: []
          properties:
            targetRef:
              type: object
            updatePolicy:
              type: object
              properties:
                updateMode:
                  type: string
            resourcePolicy:
              type: object
              properties:
                containerPolicies:
                  type: array
                  items:
                    type: object
                    properties:
                      containerName:
                        type: string
                      controlledValues:
                        type: string
                        enum: ["RequestsAndLimits", "RequestsOnly"]
                      mode:
                        type: string
                        enum: ["Auto", "Off"]
                      minAllowed:
                        type: object
                      maxAllowed:
                        type: object
                      controlledResources:
                        type: array
                        items:
                          type: string
                          enum: ["cpu", "memory"]
---
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
  name: verticalpodautoscalercheckpoints.autoscaling.k8s.io
  annotations:
    "api-approved.kubernetes.io": "https://github.com/kubernetes/kubernetes/pull/63797"
spec:
  group: autoscaling.k8s.io
  scope: Namespaced
  names:
    plural: verticalpodautoscalercheckpoints
    singular: verticalpodautoscalercheckpoint
    kind: VerticalPodAutoscalerCheckpoint
    shortNames:
      - vpacheckpoint
  version: v1beta1
  versions:
    - name: v1beta1
      served: false
      storage: false
    - name: v1beta2
      served: true
      storage: true
    - name: v1
      served: true
      storage: false

apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
  name: verticalpodautoscalers.autoscaling.k8s.io
  annotations:
    "api-approved.kubernetes.io": "https://github.com/kubernetes/kubernetes/pull/63797"
spec:
  group: autoscaling.k8s.io
  scope: Namespaced
  names:
    plural: verticalpodautoscalers
    singular: verticalpodautoscaler
    kind: VerticalPodAutoscaler
    shortNames:
      - vpa
  versions:
    - name: v1beta1
      served: false
      storage: false
      schema:
        # openAPIV3Schema is the schema for validating custom objects.
        openAPIV3Schema:
          type: object
          properties:
            spec:
              type: object
              required: []
              properties:
                targetRef:
                  type: object
                updatePolicy:
                  type: object
                  properties:
                    updateMode:
                      type: string
                resourcePolicy:
                  type: object
                  properties:
                    containerPolicies:
                      type: array
                      items:
                        type: object
                        properties:
                          containerName:
                            type: string
                          controlledValues:
                            type: string
                            enum: ["RequestsAndLimits", "RequestsOnly"]
                          mode:
                            type: string
                            enum: ["Auto", "Off"]
                          minAllowed:
                            type: object
                          maxAllowed:
                            type: object
                          controlledResources:
                            type: array
                            items:
                              type: string
                              enum: ["cpu", "memory"]
    - name: v1beta2
      served: true
      storage: true
      schema:
        # openAPIV3Schema is the schema for validating custom objects.
        openAPIV3Schema:
          type: object
          properties:
            spec:
              type: object
              required: []
              properties:
                targetRef:
                  type: object
                updatePolicy:
                  type: object
                  properties:
                    updateMode:
                      type: string
                resourcePolicy:
                  type: object
                  properties:
                    containerPolicies:
                      type: array
                      items:
                        type: object
                        properties:
                          containerName:
                            type: string
                          controlledValues:
                            type: string
                            enum: ["RequestsAndLimits", "RequestsOnly"]
                          mode:
                            type: string
                            enum: ["Auto", "Off"]
                          minAllowed:
                            type: object
                          maxAllowed:
                            type: object
                          controlledResources:
                            type: array
                            items:
                              type: string
                              enum: ["cpu", "memory"]
    - name: v1
      served: true
      storage: false
      schema:
        # openAPIV3Schema is the schema for validating custom objects.
        openAPIV3Schema:
          type: object
          properties:
            spec:
              type: object
              required: []
              properties:
                targetRef:
                  type: object
                updatePolicy:
                  type: object
                  properties:
                    updateMode:
                      type: string
                resourcePolicy:
                  type: object
                  properties:
                    containerPolicies:
                      type: array
                      items:
                        type: object
                        properties:
                          containerName:
                            type: string
                          controlledValues:
                            type: string
                            enum: ["RequestsAndLimits", "RequestsOnly"]
                          mode:
                            type: string
                            enum: ["Auto", "Off"]
                          minAllowed:
                            type: object
                          maxAllowed:
                            type: object
                          controlledResources:
                            type: array
                            items:
                              type: string
                              enum: ["cpu", "memory"]

---
apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
  name: verticalpodautoscalercheckpoints.autoscaling.k8s.io
  annotations:
    "api-approved.kubernetes.io": "https://github.com/kubernetes/kubernetes/pull/63797"
spec:
  group: autoscaling.k8s.io
  scope: Namespaced
  names:
    plural: verticalpodautoscalercheckpoints
    singular: verticalpodautoscalercheckpoint
    kind: VerticalPodAutoscalerCheckpoint
    shortNames:
      - vpacheckpoint
  versions:
    - name: v1beta1
      served: false
      storage: false
      schema:
        openAPIV3Schema:
          type: object
          properties:
            spec:
              type: object
              properties:
                cronSpec:
                  type: string
                image:
                  type: string
                replicas:
                  type: integer
    - name: v1beta2
      served: true
      storage: true
      schema:
        openAPIV3Schema:
          type: object
          properties:
            spec:
              type: object
              properties:
                cronSpec:
                  type: string
                image:
                  type: string
                replicas:
                  type: integer
    - name: v1
      served: true
      storage: false
      schema:
        openAPIV3Schema:
          type: object
          properties:
            spec:
              type: object
              properties:
                cronSpec:
                  type: string
                image:
                  type: string
                replicas:
                  type: integer

Install the components of vertical-pod-autoscaler.

vertical-pod-autoscaler contains the following components: admission-controller, recommender, and updater.

Note Before you install the admission-controller component, you must use the script to generate a certificate for a webhook.

Install admission-controller Install recommender Install updater

Use the following YAML template to install admission-controller:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: vpa-admission-controller
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: vpa-admission-controller
  template:
    metadata:
      labels:
        app: vpa-admission-controller
    spec:
      serviceAccountName: admin
      containers:
        - name: admission-controller
          image: registry.cn-hangzhou.aliyuncs.com/acs/vpa-admission-controller:0.7.0
          imagePullPolicy: Always
          env:
            - name: NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
          volumeMounts:
            - name: tls-certs
              mountPath: "/etc/tls-certs"
              readOnly: true
          resources:
            limits:
              cpu: 200m
              memory: 500Mi
            requests:
              cpu: 50m
              memory: 200Mi
          ports:
            - containerPort: 8000
      volumes:
        - name: tls-certs
          secret:
            secretName: vpa-tls-certs
---
apiVersion: v1
kind: Service
metadata:
  name: vpa-webhook
  namespace: kube-system
spec:
  ports:
    - port: 443
      targetPort: 8000
  selector:
    app: vpa-admission-controller

Use the following YAML template to install recommender:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: vpa-recommender
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: vpa-recommender
  template:
    metadata:
      labels:
        app: vpa-recommender
    spec:
      serviceAccountName: admin
      containers:
      - name: recommender
        image: registry.cn-hangzhou.aliyuncs.com/acs/vpa-recommender:0.7.0
        imagePullPolicy: Always
        resources:
          limits:
            cpu: 200m
            memory: 1000Mi
          requests:
            cpu: 50m
            memory: 500Mi
        ports:
        - containerPort: 8080

Use the following YAML template to install updater:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: vpa-updater
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: vpa-updater
  template:
    metadata:
      labels:
        app: vpa-updater
    spec:
      serviceAccountName: admin
      containers:
        - name: updater
          image: registry.cn-hangzhou.aliyuncs.com/acs/vpa-updater:0.7.0
          imagePullPolicy: Always
          resources:
            limits:
              cpu: 200m
              memory: 1000Mi
            requests:
              cpu: 50m
              memory: 500Mi
          ports:
            - containerPort: 8080

Verify that the VPA is installed

Use the following YAML template to create a Deployment named nginx-deployment-basic and a VPA resource named nginx-deployment-basic-vpa.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment-basic
  labels:
    app: nginx
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80
---
apiVersion: autoscaling.k8s.io/v1
kind: VerticalPodAutoscaler
metadata:
  name: nginx-deployment-basic-vpa
spec:
  targetRef:
    apiVersion: "apps/v1"
    kind:       Deployment
    name:       nginx-deployment-basic
  updatePolicy:
    updateMode: "Off"

Note Set updateMode to Off, and leave the requests and limits fields in the Deployment empty.

Run the following command to query the CPU request and memory request that the VPC recommends for the Deployment:
Note The output is returned 2 minutes after you run the command to query the CPU request and memory request that the VPA recommends for the Deployment.
```
kubectl describe vpa nginx-deployment-basic-vpa
```
The following output shows the recommended resource requests:
```
recommendation:
    containerRecommendations:
    - containerName: nginx
      lowerBound:
        cpu: 50m
        memory: 300144k
      target:
        cpu: 50m
        memory: 300144k
      upperBound:
        cpu: 8031m
        memory: 800000k
```
You can set resource requests for the Deployment based on the recommendation. The VPA continuously monitors the resource usage of the Deployment and provides suggestions on how to improve resource utilization.