HPA ScalingLimited=True TooFewReplicas

Question

那是我的HPA。我想用默认的replicas=3启动部署

apiVersion: autoscaling/v2beta2
kind: HorizontalPodAutoscaler
metadata:
  name: backend-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: backend

  minReplicas: 3
  maxReplicas: 20

  metrics:
    - type: Resource
      resource:
        name: memory
        target:
          type: AverageValue
          averageValue: 500Mi
    - type: Resource
      resource:
        name: cpu
        target:
          type: Utilization
          averageUtilization: 70

  behavior:
    scaleDown:
      stabilizationWindowSeconds: 300
      policies:
        - type: Pods
          value: 1
          periodSeconds: 100

    scaleUp:
      stabilizationWindowSeconds: 60
      policies:
        - type: Pods
          value: 1
          periodSeconds: 30
        - type: Percent
          value: 10
          periodSeconds: 60
      selectPolicy: Max

但是它总是说：，ScalingLimited，True，TooFewReplicas，所需的副本数小于最小副本数，我不明白为什么。

➜ kg hpa
NAME                  REFERENCE                    TARGETS                       MINPODS   MAXPODS   REPLICAS   AGE
prod-backend-hpa-v1   Deployment/prod-backend-v1   145881770666m/500Mi, 2%/70%   3         20        3          7m16s


➜ kd hpa
Name:                                                  prod-backend-hpa-v1
Namespace:                                             prod
Labels:                                                argocd.argoproj.io/instance=backend-prod
Annotations:                                           <none>
CreationTimestamp:                                     Thu, 02 Jun 2022 19:34:30 -0500
Reference:                                             Deployment/prod-backend-v1
Metrics:                                               ( current / target )
  resource memory on pods:                             145596416 / 500Mi
  resource cpu on pods  (as a percentage of request):  1% (3m) / 70%
Min replicas:                                          3
Max replicas:                                          20
Behavior:
  Scale Up:
    Stabilization Window: 60 seconds
    Select Policy: Max
    Policies:
      - Type: Pods     Value: 1   Period: 30 seconds
      - Type: Percent  Value: 10  Period: 60 seconds
  Scale Down:
    Stabilization Window: 300 seconds
    Select Policy: Max
    Policies:
      - Type: Pods  Value: 1  Period: 100 seconds
Deployment pods:    3 current / 3 desired
Conditions:
  Type            Status  Reason            Message
  ----            ------  ------            -------
  AbleToScale     True    ReadyForNewScale  recommended size matches current size
  ScalingActive   True    ValidMetricFound  the HPA was able to successfully calculate a replica count from memory resource
  ScalingLimited  True    TooFewReplicas    the desired replica count is less than the minimum replica count
Events:
  Type    Reason             Age    From                       Message
  ----    ------             ----   ----                       -------
  Normal  SuccessfulRescale  9m22s  horizontal-pod-autoscaler  New size: 3; reason: Current number of replicas below Spec.MinReplicas



➜ kgpo  
NAME                              READY   STATUS    RESTARTS   AGE
prod-backend-v1-8dd687999-54mzp   1/1     Running   0          58m
prod-backend-v1-8dd687999-nn7c2   1/1     Running   0          2d17h
prod-backend-v1-8dd687999-rcxsw   1/1     Running   0          2d17h

➜ kg rs 
NAME                         DESIRED   CURRENT   READY   AGE
prod-backend-v1-566b9c8856   0         0         0       2d19h
prod-backend-v1-578d699c45   0         0         0       2d19h
prod-backend-v1-64859b74c9   0         0         0       2d18h
prod-backend-v1-6498b4b45c   0         0         0       2d19h
prod-backend-v1-656cccdc4b   0         0         0       2d19h
prod-backend-v1-66cc5cf44    0         0         0       2d19h
prod-backend-v1-698c7ddc7d   0         0         0       2d19h
prod-backend-v1-6bdbc77f5d   0         0         0       2d19h
prod-backend-v1-7486c95664   0         0         0       2d19h
prod-backend-v1-774cdbdcdc   0         0         0       2d19h
prod-backend-v1-8dd687999    3         3         3       2d17

Answer 1

由HorizontalPodAutoscaler对象定义的水平结荚自动分配器根据从属于复制控制器或部署配置的荚收集的度量，指定系统应如何自动增加或减少复制控制器或部署配置的规模。

ScalingLimited表示不允许自动标度，因为达到了最大或最小的副本计数。

1. True条件指示您需要提高或降低最小或最大副本计数才能进行缩放。
2. False条件指示允许进行所请求的缩放。

根据您的用例，ScalingLimited将状态显示为“True”，其中包含消息“所需副本计数小于最小副本计数”。因此，作为一种解决办法，您可以增加minReplicas或设置具有大periodSeconds的scaleDown策略来增加稳定周期。

有关更多信息，请参考吊舱自动标度。