<p>I am using a Horizontal Pod Autoscaler in Kubernetes as shown below. I want to use it for a service to scale between 4 and 40 replicas. Unfortunately due to the upscale delay it would take roughly an hour to scale from 4 to 40 replicas. Is there any chance I could provide something like a min/max Surge to upscale replicas? So that it would at least upscale by 2 or 4 replicas?</p>

<p>My API Object (helm):</p>

<pre><code>apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
  name: {{ required "A valid service.name entry required!" .Values.service.name }}
  labels:
    app: {{ .Values.service.name }}
    version: {{ .Values.image.tag | quote }}
    chart: {{ template "nodejs.chart" . }}
    release: "{{ .Release.Name }}-{{ .Values.image.tag }}"
    heritage: {{ .Release.Service }}
spec:
  scaleTargetRef:
    apiVersion: apps/v1beta1
    kind: Deployment
    name: {{ required "A valid service.name entry required!" .Values.service.name }}
  minReplicas: {{ .Values.autoscaling.minReplicas }}
  maxReplicas: {{ .Values.autoscaling.maxReplicas }}
  metrics:
  - type: Resource
    resource:
      name: cpu
      targetAverageValue: {{ required "A valid autoscaling.cpuTargetValue entry is required" .Values.autoscaling.cpuTargetValue }}
  - type: Resource
    resource:
      name: memory
      targetAverageValue: {{ required "A valid autoscaling.memoryTargetValue entry is required" .Values.autoscaling.memoryTargetValue }}
</code></pre>

<p>Not really. It seems that you are concerned about <em>thrashing</em>. There's not really a way to define an upscale <em>step</em> number combined with a cool off period. </p>

<p>Up until Kubernetes 1.11 you can specify the <a href="https://v1-11.docs.kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/#support-for-cooldown-delay" rel="nofollow noreferrer"><code>--horizontal-pod-autoscaler-upscale-delay</code></a> on the kube-controller-manager which defaults to 3 minutes. This may not be enough, so I created this <a href="https://github.com/kubernetes/kubernetes/issues/69428" rel="nofollow noreferrer">issue</a></p>

<p>So starting with Kubernetes 1.12 that option has been removed in favor of a <a href="https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/#support-for-cooldown-delay" rel="nofollow noreferrer">better scaling algorithm</a>.</p>
