为什么 kubernetes HPA 没有缩减 pods？

Question

我正在使用 prometheus 和适配器来扩展 HPA（自定义指标 memory_usage_bytes）。我不知道为什么 m 附加了 targetValue 并且 HPA 在不使用内存时也没有按比例缩小 pods。

我错过了什么吗？

HPA 代码

apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
  name: pros
  namespace: default
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: pros
  maxReplicas: 3
  metrics:
  - type: Pods
    pods:
      metricName: memory_usage_bytes
      targetAverageValue: 33000000

kubectl 获取 hpa

NAME   REFERENCE         TARGETS         MINPODS   MAXPODS   REPLICAS   AGE
pros   Deployment/pros   26781013333m/33M      1         3         3          19m

custom.metrics.k8.io

{
  "kind": "MetricValueList",
  "apiVersion": "custom.metrics.k8s.io/v1beta1",
  "metadata": {
    "selfLink": "/apis/custom.metrics.k8s.io/v1beta1/namespaces/default/pods/%2A/memory_usage_bytes"
  },
  "items": [
    {
      "describedObject": {
        "kind": "Pod",
        "namespace": "default",
        "name": "pros-6c9b9c5c59-57vmx",
        "apiVersion": "/v1"
      },
      "metricName": "memory_usage_bytes",
      "timestamp": "2019-07-13T12:03:10Z",
      "value": "34947072",
      "selector": null
    },
    {
      "describedObject": {
        "kind": "Pod",
        "namespace": "default",
        "name": "pros-6c9b9c5c59-957zv",
        "apiVersion": "/v1"
      },
      "metricName": "memory_usage_bytes",
      "timestamp": "2019-07-13T12:03:10Z",
      "value": "19591168",
      "selector": null
    },
    {
      "describedObject": {
        "kind": "Pod",
        "namespace": "default",
        "name": "pros-6c9b9c5c59-nczqq",
        "apiVersion": "/v1"
      },
      "metricName": "memory_usage_bytes",
      "timestamp": "2019-07-13T12:03:10Z",
      "value": "19615744",
      "selector": null
    }
  ]
}

Answer 1

至少有两个很好的理由可以解释为什么它可能不起作用：

如您在 documentation 中所见：

The current stable version, which only includes support for CPU autoscaling, can be found in the autoscaling/v1 API version. The beta version, which includes support for scaling on memory and custom metrics, can be found in autoscaling/v2beta2.

并且您正在使用：

apiVersion: autoscaling/v2beta1 在您的 HorizontalPodAutoscaler 定义中。
如果您从 custom.metrics.k8.io 示例中总结所有 3 个当前运行 pods 使用的总内存，工作负载仍然不适合仅 2 Pods当内存限制设置为 33000000 时。请注意，第一个 Pod 已经达到其 33M 的限制，并且其他 2 Pods (19591168 + 19615744) 的内存消耗仍然太高，无法将其放入单个 pod 3300000 限制。

为什么 kubernetes HPA 没有缩减 pods？

Why kubernetes HPA is not scalling down pods?

kubernetes

horizontal-pod-autoscaling