使用 kubectl 測試 HPA
本文件描述了如何在使用負載測試工具擴展或縮減 HPA 後檢查其狀態。有關如何從 Rancher UI（至少 2.3.x 版本）檢查狀態的資訊，請參閱使用 Rancher UI 管理 HPA。
為了讓 HPA 正常運作，服務部署應該為容器定義資源請求。請按照以下 hello-world 範例來測試 HPA 是否正常運作。
-
配置
kubectl以連接到您的 Kubernetes 叢集。 -
複製下面的
hello-world部署清單。Hello World 清單
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 -
將其部署到您的叢集。
# kubectl create -f <HELLO_WORLD_MANIFEST> -
根據您使用的指標類型，複製下面的其中一個 HPA：
Hello World HPA：資源指標
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：自訂指標
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 資訊和描述。確認顯示了指標資料。
資源指標
- 輸入以下命令。
# 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>
自訂指標
- 輸入以下命令。
您應該收到以下輸出。
# 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>
- 輸入以下命令。
-
為服務生成負載以測試您的 pod 是否按預期自動擴展。您可以使用任何負載測試工具（Hey、Gatling 等），但我們使用 Hey。
-
測試 pod 自動擴展是否按預期運作。
使用資源指標測試自動擴展：擴展到 2 個 Pod：CPU 使用率達到目標
使用您的負載測試工具根據 CPU 使用率擴展到兩個 pod。
- 查看您的 HPA。
您應該收到類似以下的輸出。
# 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 - 輸入以下命令以確認已擴展到兩個 pod。
您應該收到類似以下的輸出：
# 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
擴展到 3 個 Pod：CPU 使用率達到目標
使用您的負載測試工具根據 CPU 使用率擴展到 3 個 pod，
horizontal-pod-autoscaler-upscale-delay設定為 3 分鐘。- 輸入以下命令。
您應該收到類似以下的輸出
# 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 - 輸入以下命令以確認三個 pod 正在執行。
您應該收到類似以下的輸出。
# 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
縮減到 1 個 Pod：所有指標低於目標
使用您的負載測試在所有指標低於目標
horizontal-pod-autoscaler-downscale-delay（預設為 5 分鐘）時縮減到 1 個 pod。- 輸入以下命令。
# kubectl describe hpa您應該收到類似以下的輸出。
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使用自訂指標測試自動擴展：
擴展到 2 個 Pod：CPU 使用率達到目標
使用您的負載測試工具根據 CPU 使用率擴展兩個 pod。
- 輸入以下命令。
# kubectl describe hpa您應該收到類似以下的輸出。
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- 輸入以下命令以確認兩個 pod 正在執行。
# kubectl get pods您應該收到類似以下的輸出。
NAME READY STATUS RESTARTS AGE
hello-world-54764dfbf8-5pfdr 1/1 Running 0 3s
hello-world-54764dfbf8-q6l82 1/1 Running 0 6h擴展到 3 個 Pod：CPU 使用率達到目標
使用您的負載測試工具在 cpu_system 使用率達到目標時擴展到三個 pod。
- 輸入以下命令。
您應該收到類似以下的輸出：
# 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 - 輸入以下命令以確認三個 pod 正在執行。
您應該收到類似以下的輸出：
# 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
擴展到 4 個 Pod：CPU 使用率達到目標
使用您的負載測試工具根據 CPU 使用率擴展到四個 pod。
horizontal-pod-autoscaler-upscale-delay預設設定為三分鐘。- 輸入以下命令。
# kubectl describe hpa您應該收到類似以下的輸出。
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- 輸入以下命令以確認四個 pod 正在執行。
您應該收到類似以下的輸出。
# kubectl get podsNAME 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
縮減到 1 個 Pod：所有指標低於目標
使用您的負載測試工具在所有指標低於目標
horizontal-pod-autoscaler-downscale-delay時縮減到一個 pod。- 輸入以下命令。
您應該收到類似以下的輸出。
# 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 - 輸入以下命令以確認只有一個 pod 正在執行。
您應該收到類似以下的輸出。
# kubectl get podsNAME READY STATUS RESTARTS AGE
hello-world-54764dfbf8-q6l82 1/1 Running 0 6h
- 查看您的 HPA。