Kubernetes hpa无法获得内存指标（明确说明时）

Question

我正在尝试在集群中实现Pod的自动缩放。我尝试使用“虚拟”部署和hpa，但没有任何问题。现在，我正在尝试将其集成到我们的“真实”微服务中，并不断返回

Conditions:
  Type           Status  Reason                   Message
  ----           ------  ------                   -------
  AbleToScale    True    SucceededGetScale        the HPA controller was able to get the target's current scale
  ScalingActive  False   FailedGetResourceMetric  the HPA was unable to compute the replica count: missing request for memory
Events:
  Type     Reason                        Age                   From                       Message
  ----     ------                        ----                  ----                       -------
  Warning  FailedGetResourceMetric       18m (x5 over 19m)     horizontal-pod-autoscaler  unable to get metrics for resource memory: no metrics returned from resource metrics API
  Warning  FailedComputeMetricsReplicas  18m (x5 over 19m)     horizontal-pod-autoscaler  failed to get memory utilization: unable to get metrics for resource memory: no metrics returned from resource metrics API
  Warning  FailedComputeMetricsReplicas  16m (x7 over 18m)     horizontal-pod-autoscaler  failed to get memory utilization: missing request for memory
  Warning  FailedGetResourceMetric       4m38s (x56 over 18m)  horizontal-pod-autoscaler  missing request for memory

这是我的hpa：

apiVersion: autoscaling/v2beta2
kind: HorizontalPodAutoscaler
metadata:
 name: #{Name}
 namespace: #{Namespace}
spec:
 scaleTargetRef:
   apiVersion: apps/v1beta1
   kind: Deployment
   name: #{Name}
 minReplicas: 2
 maxReplicas: 5
 metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 80
  - type: Resource
    resource:
      name: memory
      target:
        type: Utilization
        averageUtilization: 80

部署

apiVersion: apps/v1
kind: Deployment
metadata:
  name: #{Name}
  namespace: #{Namespace}
spec:
  replicas: 2
  selector:
    matchLabels:
      app: #{Name}
  template:
    metadata:
      annotations:
        linkerd.io/inject: enabled
      labels:
        app: #{Name}
    spec:
      containers:
      - name: #{Name}
        image: #{image}
        resources:
          limits:
            cpu: 500m
            memory: "300Mi"
          requests:
            cpu: 100m
            memory: "200Mi"
        ports:
        - containerPort: 80
          name: #{ContainerPort}

kubectl top pods可以同时看到内存和cpu。当我执行kubectl describe pod时，我也可以看到请求和限制。

    Limits:
      cpu:     500m
      memory:  300Mi
    Requests:
      cpu:     100m
      memory:  200Mi

我唯一能想到的是我的虚拟服务没有链接器sidecar。

Answer 1

为了使HPA使用资源度量标准，Pod的每个容器需要对给定资源（CPU或内存）的请求。

似乎Pod中的Linkerd sidecar容器未定义内存请求（它可能有CPU请求）。这就是HPA抱怨missing request for memory的原因。

但是，您可以使用--proxy-cpu-request和--proxy-memory-request injection flags配置Linkerd容器的内存和CPU请求。

另一种可能性是使用these annotations来配置CPU和内存请求：

• config.linkerd.io/proxy-cpu-request
• config.linkerd.io/proxy-memory-request

通过这两种方式之一定义内存请求都应使HPA正常工作。

参考：

• Linkerd问题最初报告为in this issue，已在this pull request中修复
• 在Linkerd 2.3.0中，--proxy-cpu-request和--proxy-memory-request替换为--proxy-cpu和--proxy-memory
• Istio sidecar出现了类似的问题，但似乎也已解决