HPA
HPA v1
资源清单文件
apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
name: myapp
namespace: default
spec:
# 最大扩容副本数量
maxReplicas: 5
# 最小副本数量
minReplicas: 1
scaleTargetRef:
apiVersion: extensions/v1beta1
kind: Deployment
name: myapp
# 目标Pod的CPU利用率超过60%就开始触发扩容
targetCPUUtilizationPercentage: 60
---
apiVersion: v1
kind: Service
metadata:
name: myapp-svc
spec:
selector:
app: myapp
type: ClusterIP
ports:
- name: http
port: 80
targetPort: 80
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: myapp
labels:
app: myapp
spec:
replicas: 1
selector:
matchLabels:
app: myapp
template:
metadata:
labels:
app: myapp
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
resources:
requests:
cpu: "100m"
memory: "128Mi"
limits:
cpu: "100m"
memory: "128Mi"
通过ab进行压测，只要客户端请求量足够，不出意外可以看到类似如下的自动扩容副本的事件信息
# kubectl describe hpa myapp
Name: myapp
Namespace: default
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"autoscaling/v1","kind":"HorizontalPodAutoscaler","metadata":{"annotations":{},"name":"myapp","namespace":"default"},"spec":{"maxReplicas...
CreationTimestamp: Mon, 08 Oct 2018 16:33:11 +0800
Reference: Deployment/myapp
Metrics: ( current / target )
resource cpu on pods (as a percentage of request): 46% (46m) / 60%
Min replicas: 1
Max replicas: 5
Deployment pods: 1 current / 1 desired
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 cpu resource utilization (percentage of request)
ScalingLimited False DesiredWithinRange the desired count is within the acceptable range
Events: <none>
[root@node001 schedule]# kubectl describe hpa myapp
Name: myapp
Namespace: default
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"autoscaling/v1","kind":"HorizontalPodAutoscaler","metadata":{"annotations":{},"name":"myapp","namespace":"default"},"spec":{"maxReplicas...
CreationTimestamp: Mon, 08 Oct 2018 16:33:11 +0800
Reference: Deployment/myapp
Metrics: ( current / target )
resource cpu on pods (as a percentage of request): 95% (95m) / 60%
Min replicas: 1
Max replicas: 5
Deployment pods: 2 current / 2 desired
Conditions:
Type Status Reason Message
---- ------ ------ -------
AbleToScale False BackoffBoth the time since the previous scale is still within both the downscale and upscale forbidden windows
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 45s horizontal-pod-autoscaler New size: 2; reason: cpu resource utilization (percentage of request) above target
HPA v2
apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
name: myapp
namespace: default
spec:
maxReplicas: 5
minReplicas: 1
scaleTargetRef:
apiVersion: extensions/v1beta1
kind: Deployment
name: myapp
# Metrics 支持CPU、内存以及自定义指标作为副本扩容条件，非常Nice~~
metrics:
- type: Resource
resource:
name: cpu
targetAverageUtilization: 55
- type: Resource
resource:
name: memory
targetAverageValue: 50Mi
---
...
压测观察扩容情况
# kubectl describe hpa myapp
Name: myapp
Namespace: default
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"autoscaling/v2beta1","kind":"HorizontalPodAutoscaler","metadata":{"annotations":{},"name":"myapp","namespace":"default"},"spec":{"maxRep...
CreationTimestamp: Mon, 08 Oct 2018 16:59:30 +0800
Reference: Deployment/myapp
Metrics: ( current / target )
resource memory on pods: 2924544 / 50Mi
resource cpu on pods (as a percentage of request): 82% (82m) / 55%
Min replicas: 1
Max replicas: 5
Deployment pods: 1 current / 2 desired
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
---- ------ ---- ---- -------
Warning FailedGetResourceMetric 35s (x3 over 1m) horizontal-pod-autoscaler unable to get metrics for resource memory: no metrics returned from resource metrics API
Warning FailedComputeMetricsReplicas 35s (x3 over 1m) horizontal-pod-autoscaler failed to get memory utilization: unable to get metrics for resource memory: no metrics returned from resource metrics API
Normal SuccessfulRescale 5s horizontal-pod-autoscaler New size: 2; reason: cpu resource utilization (percentage of request) above target