Kubernetes Pod垂直自动伸缩（VPA） |
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VPA 简介
VPA 全称 Vertical Pod Autoscaler，即垂直 Pod 自动扩缩容，它根据容器资源使用率自动设置 CPU 和 内存 的requests，从而允许在节点上进行适当的调度，以便为每个 Pod 提供适当的资源。 它既可以缩小过度请求资源的容器，也可以根据其使用情况随时提升资源不足的容量。 PS: VPA不会改变Pod的资源limits值。 废话不多说，直接上图，看VPA工作流程 image.png接下来开始实战 部署metrics-server1、下载部署清单文件 wget https://github.com/kubernetes-sigs/metrics-server/releases/download/v0.3.7/components.yaml2、修改components.yaml文件 修改了镜像地址，gcr.io为我自己的仓库 修改了metrics-server启动参数args，要不然会报错unable to fully scrape metrics from source kubelet_summary... - name: metrics-server image: scofield/metrics-server:v0.3.7 imagePullPolicy: IfNotPresent args: - --cert-dir=/tmp - --secure-port=4443 - /metrics-server - --kubelet-insecure-tls - --kubelet-preferred-address-types=InternalIP3、执行部署 kubectl apply -f components.yaml4、验证 [root@k8s-node001 metrics-server]# kubectl get po -n kube-system NAME READY STATUS RESTARTS AGE metrics-server-7947cb98b6-xw6b8 1/1 Running 0 10m 能获取要top信息视为成功 [root@k8s-node001 metrics-server]# kubectl top nodes NAME CPU(cores) CPU% MEMORY(bytes) MEMORY% k8s-node001 618m 7% 4796Mi 15% k8s-node003 551m 6% 5522Mi 17% k8s-node004 308m 3% 5830Mi 18% k8s-node005 526m 6% 5997Mi 38% k8s-node002 591m 7% 5306Mi 33% 部署vertical-pod-autoscaler1、克隆autoscaler项目 git clone https://github.com/kubernetes/autoscaler.git2、修改部署文件，将gcr仓库该为我自己的仓库 admission-controller-deployment.yaml us.gcr.io/k8s-artifacts-prod/autoscaling/vpa-admission-controller:0.8.0 改为 scofield/vpa-admission-controller:0.8.0 recommender-deployment.yaml us.gcr.io/k8s-artifacts-prod/autoscaling/vpa-recommender:0.8.0 改为 image: scofield/vpa-recommender:0.8.0 updater-deployment.yaml us.gcr.io/k8s-artifacts-prod/autoscaling/vpa-updater:0.8.0 改为 scofield/vpa-updater:0.8.03、部署 [root@k8s-node001 vertical-pod-autoscaler]# cd autoscaler/vertical-pod-autoscaler [root@k8s-node001 vertical-pod-autoscaler]# ./hack/vpa-up.sh Warning: apiextensions.k8s.io/v1beta1 CustomResourceDefinition is deprecated in v1.16+, unavailable in v1.22+; use apiextensions.k8s.io/v1 CustomResourceDefinition customresourcedefinition.apiextensions.k8s.io/verticalpodautoscalers.autoscaling.k8s.io created customresourcedefinition.apiextensions.k8s.io/verticalpodautoscalercheckpoints.autoscaling.k8s.io created clusterrole.rbac.authorization.k8s.io/system:metrics-reader created clusterrole.rbac.authorization.k8s.io/system:vpa-actor created clusterrole.rbac.authorization.k8s.io/system:vpa-checkpoint-actor created clusterrole.rbac.authorization.k8s.io/system:evictioner created clusterrolebinding.rbac.authorization.k8s.io/system:metrics-reader created clusterrolebinding.rbac.authorization.k8s.io/system:vpa-actor created clusterrolebinding.rbac.authorization.k8s.io/system:vpa-checkpoint-actor created clusterrole.rbac.authorization.k8s.io/system:vpa-target-reader created clusterrolebinding.rbac.authorization.k8s.io/system:vpa-target-reader-binding created clusterrolebinding.rbac.authorization.k8s.io/system:vpa-evictionter-binding created serviceaccount/vpa-admission-controller created clusterrole.rbac.authorization.k8s.io/system:vpa-admission-controller created clusterrolebinding.rbac.authorization.k8s.io/system:vpa-admission-controller created clusterrole.rbac.authorization.k8s.io/system:vpa-status-reader created clusterrolebinding.rbac.authorization.k8s.io/system:vpa-status-reader-binding created serviceaccount/vpa-updater created deployment.apps/vpa-updater created serviceaccount/vpa-recommender created deployment.apps/vpa-recommender created Generating certs for the VPA Admission Controller in /tmp/vpa-certs. Generating RSA private key, 2048 bit long modulus (2 primes) ............................................................................+++++ .+++++ e is 65537 (0x010001) Generating RSA private key, 2048 bit long modulus (2 primes) ............+++++ ...........................................................................+++++ e is 65537 (0x010001) Signature ok subject=CN = vpa-webhook.kube-system.svc Getting CA Private Key Uploading certs to the cluster. secret/vpa-tls-certs created Deleting /tmp/vpa-certs. deployment.apps/vpa-admission-controller created service/vpa-webhook created4、查看结果，可以看到metrics-server和vpa都已经正常运行了 [root@k8s-node001 autoscaler-master]# kubectl get po -n kube-system NAME READY STATUS RESTARTS AGE metrics-server-7947cb98b6-xw6b8 1/1 Running 0 46m vpa-admission-controller-7d87559549-g77h9 1/1 Running 0 10m vpa-recommender-84bf7fb9db-65669 1/1 Running 0 10m vpa-updater-79cc46c7bb-5p889 1/1 Running 0 10m 示例1 updateMode: "Off"1、首先我们部署一个nginx服务,部署到namespace: vpa中 apiVersion: apps/v1 kind: Deployment metadata: labels: app: nginx name: nginx namespace: vpa spec: replicas: 2 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - image: nginx name: nginx resources: requests: cpu: 100m memory: 250Mi看下结果，正常运行了2个pod [root@k8s-node001 examples]# kubectl get po -n vpa NAME READY STATUS RESTARTS AGE pod/nginx-6884b849f7-fswx5 1/1 Running 0 5m54s pod/nginx-6884b849f7-wz6b8 1/1 Running 0 5m54s2、为了便宜压测，我们创建一个NodePort类型的service [root@k8s-node001 examples]# cat nginx-vpa-ingress.yaml apiVersion: v1 kind: Service metadata: name: nginx namespace: vpa spec: type: NodePort ports: - port: 80 targetPort: 80 selector: app: nginx [root@k8s-node001 examples]# kubectl get svc -n vpa NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nginx NodePort 10.97.250.131 80:32621/TCP 55s [root@k8s-node001 examples]# curl -I 192.168.100.185:32621 HTTP/1.1 200 OK3、创建VPA 这里先使用updateMode: "Off"模式，这种模式仅获取资源推荐不更新Pod [root@k8s-node001 examples]# cat nginx-vpa-demo.yaml apiVersion: autoscaling.k8s.io/v1beta2 kind: VerticalPodAutoscaler metadata: name: nginx-vpa namespace: vpa spec: targetRef: apiVersion: "apps/v1" kind: Deployment name: nginx updatePolicy: updateMode: "Off" resourcePolicy: containerPolicies: - containerName: "nginx" minAllowed: cpu: "250m" memory: "100Mi" maxAllowed: cpu: "2000m" memory: "2048Mi"4、查看部署结果 [root@k8s-node001 examples]# kubectl get vpa -n vpa NAME AGE nginx-vpa 2m34s5、使用describe查看vpa详情，主要关注Container Recommendations [root@k8s-node001 examples]# kubectl describe vpa nginx-vpa -n vpa Name: nginx-vpa Namespace: vpa ....略去10000字 哈哈...... Update Policy: Update Mode: Off Status: Conditions: Last Transition Time: 2020-09-28T04:04:25Z Status: True Type: RecommendationProvided Recommendation: Container Recommendations: Container Name: nginx Lower Bound: Cpu: 250m Memory: 262144k Target: Cpu: 250m Memory: 262144k Uncapped Target: Cpu: 25m Memory: 262144k Upper Bound: Cpu: 803m Memory: 840190575 Events:其中 Lower Bound: 下限值 Target: 推荐值 Upper Bound: 上限值 Uncapped Target: 如果没有为VPA提供最小或最大边界，则表示目标利用率 上述结果表明，推荐的 Pod 的 CPU 请求为 25m，推荐的内存请求为 262144k 字节。6、现在我们对nginx进行压测 执行压测命令 [root@k8s-node001 examples]# ab -c 100 -n 10000000 http://192.168.100.185:32621/ This is ApacheBench, Version 2.3 Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/ Licensed to The Apache Software Foundation, http://www.apache.org/ Benchmarking 192.168.100.185 (be patient) Completed 1000000 requests Completed 2000000 requests Completed 3000000 requests7、几分钟后再观察VPA Recommendation变化 [root@k8s-node001 ~]# kubectl describe vpa nginx-vpa -n vpa |tail -n 20 Conditions: Last Transition Time: 2020-09-28T04:04:25Z Status: True Type: RecommendationProvided Recommendation: Container Recommendations: Container Name: nginx Lower Bound: Cpu: 250m Memory: 262144k Target: Cpu: 476m Memory: 262144k Uncapped Target: Cpu: 476m Memory: 262144k Upper Bound: Cpu: 2 Memory: 387578728 Events:从输出信息可以看出，VPA对Pod给出了推荐值：Cpu: 476m，因为我们这里设置了updateMode: "Off"，所以不会更新Pod 示例2 updateMode: "Auto"1、现在我把updateMode: "Auto"，看看VPA会有什么动作 这里我把resources改为：memory: 50Mi，cpu: 100m [root@k8s-node001 examples]# kubectl apply -f nginx-vpa.yaml deployment.apps/nginx created [root@k8s-node001 examples]# cat nginx-vpa.yaml apiVersion: apps/v1 kind: Deployment metadata: labels: app: nginx name: nginx namespace: vpa spec: replicas: 2 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - image: nginx name: nginx resources: requests: cpu: 100m memory: 50Mi [root@k8s-node001 examples]# kubectl get po -n vpa NAME READY STATUS RESTARTS AGE nginx-7ff65f974c-f4vgl 1/1 Running 0 114s nginx-7ff65f974c-v9ccx 1/1 Running 0 114s2、再次部署vpa,这里VPA部署文件nginx-vpa-demo.yaml只改了updateMode: "Auto"和name: nginx-vpa-2 [root@k8s-node001 examples]# cat nginx-vpa-demo.yaml apiVersion: autoscaling.k8s.io/v1beta2 kind: VerticalPodAutoscaler metadata: name: nginx-vpa-2 namespace: vpa spec: targetRef: apiVersion: "apps/v1" kind: Deployment name: nginx updatePolicy: updateMode: "Auto" resourcePolicy: containerPolicies: - containerName: "nginx" minAllowed: cpu: "250m" memory: "100Mi" maxAllowed: cpu: "2000m" memory: "2048Mi" [root@k8s-node001 examples]# kubectl apply -f nginx-vpa-demo.yaml verticalpodautoscaler.autoscaling.k8s.io/nginx-vpa created [root@k8s-node001 examples]# kubectl get vpa -n vpa NAME AGE nginx-vpa-2 9s3、再次压测 ab -c 1000 -n 100000000 http://192.168.100.185:32621/4、几分钟后，使用describe查看vpa详情，同样只关注Container Recommendations [root@k8s-node001 ~]# kubectl describe vpa nginx-vpa-2 -n vpa |tail -n 30 Min Allowed: Cpu: 250m Memory: 100Mi Target Ref: API Version: apps/v1 Kind: Deployment Name: nginx Update Policy: Update Mode: Auto Status: Conditions: Last Transition Time: 2020-09-28T04:48:25Z Status: True Type: RecommendationProvided Recommendation: Container Recommendations: Container Name: nginx Lower Bound: Cpu: 250m Memory: 262144k Target: Cpu: 476m Memory: 262144k Uncapped Target: Cpu: 476m Memory: 262144k Upper Bound: Cpu: 2 Memory: 262144k Events:Target变成了Cpu: 587m ，Memory: 262144k 5、来看下event事件 [root@k8s-node001 ~]# kubectl get event -n vpa LAST SEEN TYPE REASON OBJECT MESSAGE 33m Normal Pulling pod/nginx-7ff65f974c-f4vgl Pulling image "nginx" 33m Normal Pulled pod/nginx-7ff65f974c-f4vgl Successfully pulled image "nginx" in 15.880996269s 33m Normal Created pod/nginx-7ff65f974c-f4vgl Created container nginx 33m Normal Started pod/nginx-7ff65f974c-f4vgl Started container nginx 26m Normal EvictedByVPA pod/nginx-7ff65f974c-f4vgl Pod was evicted by VPA Updater to apply resource recommendation. 26m Normal Killing pod/nginx-7ff65f974c-f4vgl Stopping container nginx 35m Normal Scheduled pod/nginx-7ff65f974c-hnzr5 Successfully assigned vpa/nginx-7ff65f974c-hnzr5 to k8s-node005 35m Normal Pulling pod/nginx-7ff65f974c-hnzr5 Pulling image "nginx" 34m Normal Pulled pod/nginx-7ff65f974c-hnzr5 Successfully pulled image "nginx" in 40.750855715s 34m Normal Scheduled pod/nginx-7ff65f974c-v9ccx Successfully assigned vpa/nginx-7ff65f974c-v9ccx to k8s-node004 33m Normal Pulling pod/nginx-7ff65f974c-v9ccx Pulling image "nginx" 33m Normal Pulled pod/nginx-7ff65f974c-v9ccx Successfully pulled image "nginx" in 15.495315629s 33m Normal Created pod/nginx-7ff65f974c-v9ccx Created container nginx 33m Normal Started pod/nginx-7ff65f974c-v9ccx Started container nginx从输出信息可以了解到，vpa执行了EvictedByVPA，自动停掉了nginx，然后使用 VPA推荐的资源启动了新的nginx ，我们查看下nginx的pod可以得到确认 [root@k8s-node001 ~]# kubectl describe po nginx-7ff65f974c-2m9zl -n vpa Name: nginx-7ff65f974c-2m9zl Namespace: vpa Priority: 0 Node: k8s-node004/192.168.100.184 Start Time: Mon, 28 Sep 2020 00:46:19 -0400 Labels: app=nginx pod-template-hash=7ff65f974c Annotations: cni.projectcalico.org/podIP: 100.67.191.53/32 vpaObservedContainers: nginx vpaUpdates: Pod resources updated by nginx-vpa: container 0: cpu request, memory request Status: Running IP: 100.67.191.53 IPs: IP: 100.67.191.53 Controlled By: ReplicaSet/nginx-7ff65f974c Containers: nginx: Container ID: docker://c96bcd07f35409d47232a0bf862a76a56352bd84ef10a95de8b2e3f6681df43d Image: nginx Image ID: docker-pullable://nginx@sha256:c628b67d21744fce822d22fdcc0389f6bd763daac23a6b77147d0712ea7102d0 Port: Host Port: State: Running Started: Mon, 28 Sep 2020 00:46:38 -0400 Ready: True Restart Count: 0 Requests: cpu: 476m memory: 262144k看重点Requests：cpu: 476m，memory: 262144k 再回头看看部署文件 requests: cpu: 100m memory: 50Mi现在可以知道VPA做了哪些事了吧。当然，随着服务的负载的变化，VPA的推荐之也会不断变化。当目前运行的pod的资源达不到VPA的推荐值，就会执行pod驱逐，重新部署新的足够资源的服务。 VPA使用限制 不能与HPA（Horizontal Pod Autoscaler ）一起使用 Pod比如使用副本控制器，例如属于Deployment或者StatefulSet VPA有啥好处 Pod 资源用其所需，所以集群节点使用效率高。 Pod 会被安排到具有适当可用资源的节点上。 不必运行基准测试任务来确定 CPU 和内存请求的合适值。 VPA 可以随时调整 CPU 和内存请求，无需人为操作，因此可以减少维护时间。最后滴最后，VPA是Kubernetes比较新的功能，还没有在生产环境大规模实践过，不建议在线上环境使用自动更新模式，但是使用推荐模式你可以更好了解服务的资源使用情况。 更多信息请前往官网查看 |
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