使用 kubectl 测试 HPA
本文介绍如何在使用负载测试工具扩缩 HPA 后检查 HPA 的状态。有关使用 Rancher UI（最低版本 2.3.x）检查状态的信息，请参阅使用 Rancher UI 管理 HPA。
要让 HPA 正常工作，服务部署应该具有容器的资源请求定义。按照以下 hello-world 示例测试 HPA 是否正常工作。
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将
kubectl连接到你的 Kubernetes 集群。 -
复制下方的
hello-world部署清单。Hello World 清单
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apiVersion: apps/v1beta2 kind: Deployment metadata: labels: app: hello-world name: hello-world namespace: default spec: replicas: 1 selector: matchLabels: app: hello-world strategy: rollingUpdate: maxSurge: 1 maxUnavailable: 0 type: RollingUpdate template: metadata: labels: app: hello-world spec: containers: - image: rancher/hello-world imagePullPolicy: Always name: hello-world resources: requests: cpu: 500m memory: 64Mi ports: - containerPort: 80 protocol: TCP restartPolicy: Always --- apiVersion: v1 kind: Service metadata: name: hello-world namespace: default spec: ports: - port: 80 protocol: TCP targetPort: 80 selector: app: hello-world+
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将其部署到你的集群。
# kubectl create -f <HELLO_WORLD_MANIFEST>
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根据你使用的指标类型复制以下其中一个 HPA：
Hello World HPA：资源指标
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apiVersion: autoscaling/v2beta1 kind: HorizontalPodAutoscaler metadata: name: hello-world namespace: default spec: scaleTargetRef: apiVersion: extensions/v1beta1 kind: Deployment name: hello-world minReplicas: 1 maxReplicas: 10 metrics: - type: Resource resource: name: cpu targetAverageUtilization: 50 - type: Resource resource: name: memory targetAverageValue: 1000Mi+
+
apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
name: hello-world
namespace: default
spec:
scaleTargetRef:
apiVersion: extensions/v1beta1
kind: Deployment
name: hello-world
minReplicas: 1
maxReplicas: 10
metrics:
- type: Resource
resource:
name: cpu
targetAverageUtilization: 50
- type: Resource
resource:
name: memory
targetAverageValue: 100Mi
- type: Pods
pods:
metricName: cpu_system
targetAverageValue: 20m
+
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查看 HPA 信息和描述。确认显示的指标数据。
资源指标
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输入以下命令： ` # kubectl get hpa NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE hello-world Deployment/hello-world 1253376 / 100Mi, 0% / 50% 1 10 1 6m # kubectl describe hpa Name: hello-world Namespace: default Labels: <none> Annotations: <none> CreationTimestamp: Mon, 23 Jul 2018 20:21:16 +0200 Reference: Deployment/hello-world Metrics: ( current / target ) resource memory on pods: 1253376 / 100Mi resource cpu on pods (as a percentage of request): 0% (0) / 50% Min replicas: 1 Max replicas: 10 Conditions: Type Status Reason Message ---- ------ ------ ------- AbleToScale True ReadyForNewScale the last scale time was sufficiently old as to warrant a new scale ScalingActive True ValidMetricFound the HPA was able to successfully calculate a replica count from memory resource ScalingLimited False DesiredWithinRange the desired count is within the acceptable range Events: <none> `
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输入以下命令： ` # kubectl describe hpa ` 你应该会看到类似以下的输出： ` Name: hello-world Namespace: default Labels: <none> Annotations: <none> CreationTimestamp: Tue, 24 Jul 2018 18:36:28 +0200 Reference: Deployment/hello-world Metrics: ( current / target ) resource memory on pods: 3514368 / 100Mi "cpu_system" on pods: 0 / 20m resource cpu on pods (as a percentage of request): 0% (0) / 50% Min replicas: 1 Max replicas: 10 Conditions: Type Status Reason Message ---- ------ ------ ------- AbleToScale True ReadyForNewScale the last scale time was sufficiently old as to warrant a new scale ScalingActive True ValidMetricFound the HPA was able to successfully calculate a replica count from memory resource ScalingLimited False DesiredWithinRange the desired count is within the acceptable range Events: <none> `
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为服务生成负载，从而测试你的 pod 是否按预期进行了自动扩缩。你可以使用任何负载测试工具（Hey、Gatling 等），我们使用的是 Hey。
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测试 pod 自动扩缩是否按预期工作。
使用资源指标测试自动扩缩：扩展到两个 Pod：CPU 用量达到目标
使用你的负载测试工具根据 CPU 使用情况扩展到两个 Pod。
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查看你的 HPA。
# kubectl describe hpa
你应该会看到类似以下的输出：
Name: hello-world Namespace: default Labels: <none> Annotations: <none> CreationTimestamp: Mon, 23 Jul 2018 22:22:04 +0200 Reference: Deployment/hello-world Metrics: ( current / target ) resource memory on pods: 10928128 / 100Mi resource cpu on pods (as a percentage of request): 56% (280m) / 50% Min replicas: 1 Max replicas: 10 Conditions: Type Status Reason Message ---- ------ ------ ------- AbleToScale True SucceededRescale the HPA controller was able to update the target scale to 2 ScalingActive True ValidMetricFound the HPA was able to successfully calculate a replica count from cpu resource utilization (percentage of request) ScalingLimited False DesiredWithinRange the desired count is within the acceptable range Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal SuccessfulRescale 13s horizontal-pod-autoscaler New size: 2; reason: cpu resource utilization (percentage of request) above target
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输入以下命令，确认你已扩展到两个 pod：
# kubectl get pods
你应该会看到类似以下的输出：
NAME READY STATUS RESTARTS AGE hello-world-54764dfbf8-k8ph2 1/1 Running 0 1m hello-world-54764dfbf8-q6l4v 1/1 Running 0 3h
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使用你的负载测试工具根据 CPU 用量扩展到三个 Pod，并将 horizontal-pod-autoscaler-upscale-delay 设置为 3 分钟。
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输入以下命令：
# kubectl describe hpa
你应该会看到类似以下的输出：
Name: hello-world Namespace: default Labels: <none> Annotations: <none> CreationTimestamp: Mon, 23 Jul 2018 22:22:04 +0200 Reference: Deployment/hello-world Metrics: ( current / target ) resource memory on pods: 9424896 / 100Mi resource cpu on pods (as a percentage of request): 66% (333m) / 50% Min replicas: 1 Max replicas: 10 Conditions: Type Status Reason Message ---- ------ ------ ------- AbleToScale True SucceededRescale the HPA controller was able to update the target scale to 3 ScalingActive True ValidMetricFound the HPA was able to successfully calculate a replica count from cpu resource utilization (percentage of request) ScalingLimited False DesiredWithinRange the desired count is within the acceptable range Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal SuccessfulRescale 4m horizontal-pod-autoscaler New size: 2; reason: cpu resource utilization (percentage of request) above target Normal SuccessfulRescale 16s horizontal-pod-autoscaler New size: 3; reason: cpu resource utilization (percentage of request) above target -
输入以下命令，确认三个 pod 正在运行：
# kubectl get pods
你应该会看到类似以下的输出：
NAME READY STATUS RESTARTS AGE hello-world-54764dfbf8-f46kh 0/1 Running 0 1m hello-world-54764dfbf8-k8ph2 1/1 Running 0 5m hello-world-54764dfbf8-q6l4v 1/1 Running 0 3h
缩减到 1 个 Pod：所有指标均低于目标
当 horizontal-pod-autoscaler-downscale-delay 的所有指标均低于目标（默认为 5 分钟）时，使用你的负载测试工具缩减到 1 个 pod。
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输入以下命令：
# kubectl describe hpa
你应该会看到类似以下的输出：
Name: hello-world Namespace: default Labels: <none> Annotations: <none> CreationTimestamp: Mon, 23 Jul 2018 22:22:04 +0200 Reference: Deployment/hello-world Metrics: ( current / target ) resource memory on pods: 10070016 / 100Mi resource cpu on pods (as a percentage of request): 0% (0) / 50% Min replicas: 1 Max replicas: 10 Conditions: Type Status Reason Message ---- ------ ------ ------- AbleToScale True SucceededRescale the HPA controller was able to update the target scale to 1 ScalingActive True ValidMetricFound the HPA was able to successfully calculate a replica count from memory resource ScalingLimited False DesiredWithinRange the desired count is within the acceptable range Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal SuccessfulRescale 10m horizontal-pod-autoscaler New size: 2; reason: cpu resource utilization (percentage of request) above target Normal SuccessfulRescale 6m horizontal-pod-autoscaler New size: 3; reason: cpu resource utilization (percentage of request) above target Normal SuccessfulRescale 1s horizontal-pod-autoscaler New size: 1; reason: All metrics below target
+ 使用自定义指标测试自动缩放：
+ .扩展到两个 Pod：CPU 用量达到目标
Details
使用负载测试工具根据 CPU 用量扩展到两个 Pod。
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输入以下命令： ` # kubectl describe hpa ` 你应该会看到类似以下的输出： ` Name: hello-world Namespace: default Labels: <none> Annotations: <none> CreationTimestamp: Tue, 24 Jul 2018 18:01:11 +0200 Reference: Deployment/hello-world Metrics: ( current / target ) resource memory on pods: 8159232 / 100Mi "cpu_system" on pods: 7m / 20m resource cpu on pods (as a percentage of request): 64% (321m) / 50% Min replicas: 1 Max replicas: 10 Conditions: Type Status Reason Message ---- ------ ------ ------- AbleToScale True SucceededRescale the HPA controller was able to update the target scale to 2 ScalingActive True ValidMetricFound the HPA was able to successfully calculate a replica count from cpu resource utilization (percentage of request) ScalingLimited False DesiredWithinRange the desired count is within the acceptable range Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal SuccessfulRescale 16s horizontal-pod-autoscaler New size: 2; reason: cpu resource utilization (percentage of request) above target `
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输入以下命令，确认两个 pod 正在运行： ` # kubectl get pods ` 你应该会看到类似以下的输出： ` NAME READY STATUS RESTARTS AGE hello-world-54764dfbf8-5pfdr 1/1 Running 0 3s hello-world-54764dfbf8-q6l82 1/1 Running 0 6h `
扩展到三个 Pod：CPU 用量达到目标
当 cpu_system 用量达到目标时，使用你的负载测试工具扩展到三个 Pod。 .. 输入以下命令：
+
# kubectl describe hpa
+ 你应该会看到类似以下的输出：
+
Name: hello-world
Namespace: default
Labels: <none>
Annotations: <none>
CreationTimestamp: Tue, 24 Jul 2018 18:01:11 +0200
Reference: Deployment/hello-world
Metrics: ( current / target )
resource memory on pods: 8374272 / 100Mi
"cpu_system" on pods: 27m / 20m
resource cpu on pods (as a percentage of request): 71% (357m) / 50%
Min replicas: 1
Max replicas: 10
Conditions:
Type Status Reason Message
---- ------ ------ -------
AbleToScale True SucceededRescale the HPA controller was able to update the target scale to 3
ScalingActive True ValidMetricFound the HPA was able to successfully calculate a replica count from cpu resource utilization (percentage of request)
ScalingLimited False DesiredWithinRange the desired count is within the acceptable range
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal SuccessfulRescale 3m horizontal-pod-autoscaler New size: 2; reason: cpu resource utilization (percentage of request) above target
Normal SuccessfulRescale 3s horizontal-pod-autoscaler New size: 3; reason: pods metric cpu_system above target
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输入以下命令，确认三个 pod 正在运行：
# kubectl get pods
你应该会看到类似以下的输出：
# kubectl get pods NAME READY STATUS RESTARTS AGE hello-world-54764dfbf8-5pfdr 1/1 Running 0 3m hello-world-54764dfbf8-m2hrl 1/1 Running 0 1s hello-world-54764dfbf8-q6l82 1/1 Running 0 6h
扩展到四个 Pod：CPU 用量达到目标
使用负载测试工具根据 CPU 用量扩展到四个 Pod。horizontal-pod-autoscaler-upscale-delay 默认设置为 3 分钟。
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输入以下命令： ` # kubectl describe hpa ` 你应该会看到类似以下的输出： ` Name: hello-world Namespace: default Labels: <none> Annotations: <none> CreationTimestamp: Tue, 24 Jul 2018 18:01:11 +0200 Reference: Deployment/hello-world Metrics: ( current / target ) resource memory on pods: 8374272 / 100Mi "cpu_system" on pods: 27m / 20m resource cpu on pods (as a percentage of request): 71% (357m) / 50% Min replicas: 1 Max replicas: 10 Conditions: Type Status Reason Message ---- ------ ------ ------- AbleToScale True SucceededRescale the HPA controller was able to update the target scale to 3 ScalingActive True ValidMetricFound the HPA was able to successfully calculate a replica count from cpu resource utilization (percentage of request) ScalingLimited False DesiredWithinRange the desired count is within the acceptable range Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal SuccessfulRescale 5m horizontal-pod-autoscaler New size: 2; reason: cpu resource utilization (percentage of request) above target Normal SuccessfulRescale 3m horizontal-pod-autoscaler New size: 3; reason: pods metric cpu_system above target Normal SuccessfulRescale 4s horizontal-pod-autoscaler New size: 4; reason: cpu resource utilization (percentage of request) above target `
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输入以下命令，确认四个 pod 正在运行：
# kubectl get pods
你应该会看到类似以下的输出：
NAME READY STATUS RESTARTS AGE hello-world-54764dfbf8-2p9xb 1/1 Running 0 5m hello-world-54764dfbf8-5pfdr 1/1 Running 0 2m hello-world-54764dfbf8-m2hrl 1/1 Running 0 1s hello-world-54764dfbf8-q6l82 1/1 Running 0 6h
缩减到 1 个 Pod：所有指标均低于目标
当 horizontal-pod-autoscaler-downscale-delay 的所有指标均低于目标时，使用你的负载测试工具缩减到 1 个 pod。
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输入以下命令：
# kubectl describe hpa
你应该会看到类似以下的输出：
Name: hello-world Namespace: default Labels: <none> Annotations: <none> CreationTimestamp: Tue, 24 Jul 2018 18:01:11 +0200 Reference: Deployment/hello-world Metrics: ( current / target ) resource memory on pods: 8101888 / 100Mi "cpu_system" on pods: 8m / 20m resource cpu on pods (as a percentage of request): 0% (0) / 50% Min replicas: 1 Max replicas: 10 Conditions: Type Status Reason Message ---- ------ ------ ------- AbleToScale True SucceededRescale the HPA controller was able to update the target scale to 1 ScalingActive True ValidMetricFound the HPA was able to successfully calculate a replica count from memory resource ScalingLimited False DesiredWithinRange the desired count is within the acceptable range Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal SuccessfulRescale 10m horizontal-pod-autoscaler New size: 2; reason: cpu resource utilization (percentage of request) above target Normal SuccessfulRescale 8m horizontal-pod-autoscaler New size: 3; reason: pods metric cpu_system above target Normal SuccessfulRescale 5m horizontal-pod-autoscaler New size: 4; reason: cpu resource utilization (percentage of request) above target Normal SuccessfulRescale 13s horizontal-pod-autoscaler New size: 1; reason: All metrics below target -
输入以下命令，确认单个 pod 正在运行：
# kubectl get pods
你应该会看到类似以下的输出：
NAME READY STATUS RESTARTS AGE hello-world-54764dfbf8-q6l82 1/1 Running 0 6h