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。
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
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将其部署到你的集群。
# kubectl create -f <HELLO_WORLD_MANIFEST>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
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: 1000MiHello World HPA：自定义指标
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查看 HPA 信息和描述。确认显示的指标数据。
资源指标
- 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>
自定义指标
- 输入以下命令：你应该会看到类似以下的输出：
# kubectl describe hpaName: 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>
- 输入以下命令：
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。
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。
- 查看你的 HPA。你应该会看到类似以下的输出：
# kubectl describe hpaName: 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 - 输入以下命令，确认你已扩展到两个 pod：你应该会看到类似以下的输出：
# kubectl get podsNAME READY STATUS RESTARTS AGE
hello-world-54764dfbf8-k8ph2 1/1 Running 0 1m
hello-world-54764dfbf8-q6l4v 1/1 Running 0 3h
扩展到三个 Pod：CPU 用量达到目标
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。- 输入以下命令：你应该会看到类似以下的输出：
# kubectl describe hpaName: 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：你应该会看到类似以下的输出：
# kubectl get podsNAME 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。- 输入以下命令：你应该会看到类似以下的输出：
# kubectl describe hpaName: 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
使用负载测试工具根据 CPU 用量扩展到两个 Pod。
- 输入以下命令：你应该会看到类似以下的输出：
# kubectl describe hpaName: 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 - 输入以下命令，确认两个 pod 正在运行：你应该会看到类似以下的输出：
# kubectl get podsNAME 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：你应该会看到类似以下的输出：
# kubectl describe hpaName: 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 - 输入以下命令，确认三个 pod 正在运行：你应该会看到类似以下的输出：
# kubectl get pods# 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。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。- 输入以下命令：你应该会看到类似以下的输出：
# kubectl describe hpaName: 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：你应该会看到类似以下的输出：
# kubectl get podsNAME READY STATUS RESTARTS AGE
hello-world-54764dfbf8-q6l82 1/1 Running 0 6h
- 查看你的 HPA。