vpa 纵向容器自动缩放器（VPA）使用户无需设置最新的资源限制和对容器中容器的要求。配置后，它将根据使用情况自动设置请求，从而允许在节点上进行适当的调度，以便为每个Pod提供适当的资源量。它还将保持限制和初始容器配置中指定的请求之间的比率。
它既可以根据资源的使用情况来缩减对资源过度使用的Pod，也可以对资源需求不足的向上扩展Pod。
Kubernetes VPA 包含以下组件：
Recommender：用于根据监控指标结合内置机制给出资源建议值
Updater：用于实时更新 pod resource requests
History Storage：用于采集和存储监控数据
Admission Controller: 用于在 pod 创建时修改 resource requests
架构图
主要流程是：Recommender在启动时从History Storage获取历史数据，根据内置机制修改VPA API object资源建议值。Updater监听VPA API object，依据建议值动态修改 pod resource requests。VPA Admission Controller则是用于 pod 创建时修改 pod resource requests。History Storage则是通过Kubernetes Metrics API采集和存储监控数据。
CPU 和内存的建议值均是依据历史数据+固定机制计算而成。
在 Kubernetes VPA 中缺少资源回收的机制，但Recommender却可以配合Updater动态修改 pod resource requests 的值。也就是说 pod resource requests - 推荐值 = 资源回收值 。这间接实现了资源回收的功能。
VPA工作流程
VPA连续检查您在设置过程中配置的指标值，默认间隔为10秒
如果达到阈值，VPA会尝试更改分配的内存和/或CPU
VPA主要更新部署或复制控制器规范中的资源
重新启动Pod后，新资源将全部应用于创建的实例。
使用VPA时需要考虑以下几点：
如果不重新启动Pod，将无法更改资源。到目前为止，主要的合理性在于，这样的变化可能会导致很多不稳定。因此，考虑重新启动Pod并根据新分配的资源对其进行调度。
VPA和HPA尚不兼容，不能在同一pod上使用。如果要在同一群集中同时使用它们，请确保在设置中分开它们的作用域。
VPA仅根据观察到的过去和当前资源使用情况来调整容器的资源请求 。它没有设置资源限制 。对于行为不当的应用程序可能会出现问题，这些应用程序开始使用越来越多的资源，导致pod被Kubernetes杀死。
安装 当前默认版本是Vertical Pod Autoscaler 0.8.0
1 2 3 git clone https://github.com/kubernetes/autoscaler.git cd autoscaler ./hack/vpa-up.sh
注意：该脚本当前读取环境变量：$REGISTRY和$TAG。除非要使用VPA的非默认版本，否则请确保未设置它们。
如果出现如下报错，我们可以升级openssl到支持-addext选项的版本，或在下载via-release-0.8这个分支的代码并使用./hack/vpa-up.sh
1 2 ERROR: Failed to create CA certificate for self-signing. If the error is "unknown option -addext" , update your openssl version or deploy VPA from the vpa-release-0.8 branch. deployment.apps/vpa-admission-controller created
安装好之后会创建三个pod，这三个pod使用的镜像需要翻墙下载
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 [root@master01 vertical-pod-autoscaler] NAME READY STATUS RESTARTS AGE calico-kube-controllers-688c5dc8c7-rcn2t 1/1 Running 0 59d calico-node-n7sj8 1/1 Running 7 89d calico-node-vk9c9 1/1 Running 1 89d coredns-6955765f44-mgcc4 1/1 Running 0 59d coredns-6955765f44-vwzxt 1/1 Running 0 59d csi-disk-provisioner-0 2/2 Running 0 17d csi-diskplugin-jmw74 2/2 Running 0 17d csi-diskplugin-mv99m 2/2 Running 0 17d dex-1591193803-6844b4846c-4wwzg 1/1 Running 1 19d dex-k8s-authenticator-1591193977-54f66bd94f-tv2rl 1/1 Running 1 59d etcd-master01 1/1 Running 8 89d kube-apiserver-master01 1/1 Running 0 19d kube-controller-manager-master01 1/1 Running 0 13d kube-proxy-s98fh 1/1 Running 0 59d kube-proxy-zn2l6 1/1 Running 0 59d kube-scheduler-master01 1/1 Running 0 13d kube-sealyun-lvscare-node01 1/1 Running 0 89d kuboard-85d499bd9b-xmvtp 1/1 Running 0 15d metrics-server-6b4d999dcb-xzx4p 1/1 Running 0 13d snapshot-controller-0 1/1 Running 0 14d traefik-0 1/1 Running 0 20d vpa-admission-controller-6b88678dcb-d5vb6 1/1 Running 0 7s vpa-recommender-5fc9b4c4cb-d5j8l 1/1 Running 0 32s vpa-updater-865849df48-rcl94 1/1 Running 0 40s [root@master01 vertical-pod-autoscaler] NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES .... vpa-admission-controller 1/1 1 1 62m admission-controller us.gcr.io/k8s-artifacts-prod/autoscaling/vpa-admission-controller:0.8.0 app=vpa-admission-controller vpa-recommender 1/1 1 1 62m recommender us.gcr.io/k8s-artifacts-prod/autoscaling/vpa-recommender:0.8.0 app=vpa-recommender vpa-updater 1/1 1 1 62m updater us.gcr.io/k8s-artifacts-prod/autoscaling/vpa-updater:0.8.0 app=vpa-updater
这里可以使用 misterli/vpa-recommender:0.8.0,misterli/vpa-updater:0.8.0,misterli/vpa-admission-controller:0.8.0这三个镜像进行替换
使用
VPA 有以下四种更新策略：
•Initial：仅在 Pod 创建时修改资源请求，以后都不再修改。
•Auto：默认策略，在 Pod 创建时修改资源请求，并且在 Pod 更新时也会修改。
•Recreate：类似 Auto，在 Pod 的创建和更新时都会修改资源请求，不同的是，只要Pod 中的请求值与新的推荐值不同，VPA 都会驱逐该 Pod，然后使用新的推荐值重新启一个。因此，一般不使用该策略，而是使用 Auto，除非你真的需要保证请求值是最新的推荐值。
•Off：不改变 Pod 的资源请求，不过仍然会在 VPA 中设置资源的推荐值。
我们部署一个使用vpa的示例：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 --- apiVersion: "autoscaling.k8s.io/v1beta2" kind: VerticalPodAutoscaler metadata: name: hamster-vpa spec: targetRef: apiVersion: "apps/v1" kind: Deployment name: hamster updatePolicy: updateMode: "Auto" --- apiVersion: apps/v1 kind: Deployment metadata: name: hamster spec: selector: matchLabels: app: hamster replicas: 2 template: metadata: labels: app: hamster spec: containers: - name: hamster image: ubuntu:16.04 resources: requests: cpu: 100m memory: 50Mi command : ["/bin/sh" ] args: - "-c" - "while true; do timeout 0.5s yes >/dev/null; sleep 0.5s; done"
我们发现稍等片刻vpa会对pod的资源进行动态更新
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 [root@master01 vertical-pod-autoscaler] verticalpodautoscaler.autoscaling.k8s.io/hamster-vpa created deployment.apps/hamster created [root@master01 vertical-pod-autoscaler] NAME READY STATUS RESTARTS AGE event-exporter-56b4dbc8fb-gsmx4 1/1 Running 0 40d hamster-bb5bb8754-krljt 1/1 Running 0 21s hamster-bb5bb8754-nvhf2 1/1 Running 0 21s hamster-bb5bb8754-krljt 1/1 Terminating 0 92s hamster-bb5bb8754-qs8dl 0/1 Pending 0 0s hamster-bb5bb8754-qs8dl 0/1 Pending 0 0s hamster-bb5bb8754-qs8dl 0/1 ContainerCreating 0 0s hamster-bb5bb8754-qs8dl 0/1 ContainerCreating 0 0s hamster-bb5bb8754-qs8dl 1/1 Running 0 1s hamster-bb5bb8754-krljt 0/1 Terminating 0 2m3s hamster-bb5bb8754-krljt 0/1 Terminating 0 2m4s hamster-bb5bb8754-krljt 0/1 Terminating 0 2m4s hamster-bb5bb8754-nvhf2 1/1 Terminating 0 2m32s hamster-bb5bb8754-d2rnh 0/1 Pending 0 0s hamster-bb5bb8754-d2rnh 0/1 Pending 0 0s hamster-bb5bb8754-d2rnh 0/1 ContainerCreating 0 0s hamster-bb5bb8754-d2rnh 0/1 ContainerCreating 0 1s hamster-bb5bb8754-d2rnh 1/1 Running 0 2s
查看一下vpa的详情可以看到vpa建议的值
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 [root@master01 vertical-pod-autoscaler] Name: hamster-vpa Namespace: default ..... Recommendation: Container Recommendations: Container Name: hamster Lower Bound: Cpu: 579m Memory: 262144k Target: Cpu: 587m Memory: 262144k Uncapped Target: Cpu: 587m Memory: 262144k Upper Bound: Cpu: 4554m Memory: 262144k Events: <none>
查看当前pod的资源限制，pod的requests已经被动态调整了
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 [root@master01 vertical-pod-autoscaler] apiVersion: v1 kind: Pod .... name: hamster resources: requests: cpu: 587m memory: 262144k terminationMessagePath: /dev/termination-log terminationMessagePolicy: File volumeMounts: - mountPath: /var/run/secrets/kubernetes.io/serviceaccount name: default-token-jqvcc readOnly: true .....
还可以限制动态调整的范围
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 --- apiVersion: "autoscaling.k8s.io/v1beta2" kind: VerticalPodAutoscaler metadata: name: hamster-vpa spec: targetRef: apiVersion: "apps/v1" kind: Deployment name: hamster resourcePolicy: containerPolicies: - containerName: '*' minAllowed: cpu: 100m memory: 50Mi maxAllowed: cpu: 1 memory: 500Mi controlledResources: ["cpu" , "memory" ] --- apiVersion: apps/v1 kind: Deployment metadata: name: hamster spec: selector: matchLabels: app: hamster replicas: 2 template: metadata: labels: app: hamster spec: containers: - name: hamster image: ubuntu:16.04 resources: requests: cpu: 100m memory: 50Mi command : ["/bin/sh" ] args: - "-c" - "while true; do timeout 0.5s yes >/dev/null; sleep 0.5s; done"
上面的yaml创建了一个包含2个Pod的deployment，每个Pod运行一个请求100m cpu 的容器，并尝试使用略高于500m cpu的容器。该命令还会创建一个指向deployment的VPA配置。VPA将观察Pod的行为，大约5分钟后，它们应使用更高的CPU请求进行更新（请注意，VPA不会在deployment中修改模板，但Pod的实际请求会被更新）。要查看VPA配置和当前推荐的资源请求:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 [root@master01 vertical-pod-autoscaler] Name: hamster-vpa Namespace: default ... Status: Conditions: Last Transition Time: 2020-09-01T03:55:47Z Status: True Type: RecommendationProvided Recommendation: Container Recommendations: Container Name: hamster Lower Bound: Cpu: 552m Memory: 262144k Target: Cpu: 587m Memory: 262144k Uncapped Target: Cpu: 587m Memory: 262144k Upper Bound: Cpu: 1 Memory: 370459537 Events: <none>
查看pod 详情，发现此时 resources字段已经被更改
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 [root@master01 vertical-pod-autoscaler] apiVersion: v1 kind: Pod .... image: ubuntu:16.04 imagePullPolicy: IfNotPresent name: hamster resources: requests: cpu: 587m memory: 262144k terminationMessagePath: /dev/termination-log terminationMessagePolicy: File ... [root@master01 vertical-pod-autoscaler] NAME READY STATUS RESTARTS AGE event-exporter-56b4dbc8fb-gsmx4 1/1 Running 0 40d hamster-bb5bb8754-ghggr 1/1 Running 0 5s hamster-bb5bb8754-xnndg 1/1 Running 0 5s hamster-bb5bb8754-xnndg 1/1 Terminating 0 62s hamster-bb5bb8754-gcrbc 0/1 Pending 0 0s hamster-bb5bb8754-gcrbc 0/1 Pending 0 0s hamster-bb5bb8754-gcrbc 0/1 ContainerCreating 0 0s hamster-bb5bb8754-gcrbc 0/1 ContainerCreating 0 1s hamster-bb5bb8754-gcrbc 1/1 Running 0 1s hamster-bb5bb8754-xnndg 0/1 Terminating 0 93s hamster-bb5bb8754-xnndg 0/1 Terminating 0 94s hamster-bb5bb8754-xnndg 0/1 Terminating 0 94s hamster-bb5bb8754-ghggr 1/1 Terminating 0 2m2s hamster-bb5bb8754-gwxgw 0/1 Pending 0 0s hamster-bb5bb8754-gwxgw 0/1 Pending 0 0s hamster-bb5bb8754-gwxgw 0/1 ContainerCreating 0 0s hamster-bb5bb8754-gwxgw 0/1 ContainerCreating 0 1s hamster-bb5bb8754-gwxgw 1/1 Running 0 2s
event事件
1 2 3 4 5 6 7 8 9 10 11 12 13 14 0s Normal EvictedByVPA pod/hamster-bb5bb8754-xnndg Pod was evicted by VPA Updater to apply resource recommendation. 0s Normal SuccessfulCreate replicaset/hamster-bb5bb8754 Created pod: hamster-bb5bb8754-gcrbc 0s Normal Scheduled pod/hamster-bb5bb8754-gcrbc Successfully assigned default/hamster-bb5bb8754-gcrbc to node01 0s Normal Killing pod/hamster-bb5bb8754-xnndg Stopping container hamster 0s Normal Pulled pod/hamster-bb5bb8754-gcrbc Container image "ubuntu:16.04" already present on machine 0s Normal Created pod/hamster-bb5bb8754-gcrbc Created container hamster 0s Normal Started pod/hamster-bb5bb8754-gcrbc Started container hamster 0s Normal EvictedByVPA pod/hamster-bb5bb8754-ghggr Pod was evicted by VPA Updater to apply resource recommendation. 0s Normal Killing pod/hamster-bb5bb8754-ghggr Stopping container hamster 0s Normal SuccessfulCreate replicaset/hamster-bb5bb8754 Created pod: hamster-bb5bb8754-gwxgw 0s Normal Scheduled pod/hamster-bb5bb8754-gwxgw Successfully assigned default/hamster-bb5bb8754-gwxgw to node01 0s Normal Pulled pod/hamster-bb5bb8754-gwxgw Container image "ubuntu:16.04" already present on machine 0s Normal Created pod/hamster-bb5bb8754-gwxgw Created container hamster 0s Normal Started pod/hamster-bb5bb8754-gwxgw Started container hamster
