reconcileAutoscaler(hpav1Shared *autoscalingv1.HorizontalPodAutoscaler, key string)-->
	computeReplicasForMetrics()-->
		a.computeReplicasForMetric(hpa, metricSpec, specReplicas, statusReplicas, selector, &statuses[i])-->
		switch spec.Type {
		case autoscalingv2.ObjectMetricSourceType:
		case autoscalingv2.PodsMetricSourceType:
			a.computeStatusForPodsMetric(specReplicas, spec, hpa, selector, status, metricSelector)-->
				a.replicaCalc.GetMetricReplicas(currentReplicas, metricSpec.Pods.Target.AverageValue.MilliValue(), metricSpec.Pods.Metric.Name, hpa.Namespace, selector, metricSelector)-->
					c.metricsClient.GetRawMetric(metricName, namespace, selector, metricSelector) // get data from metrics server					
					c.calcPlainMetricReplicas(metrics, currentReplicas, targetUtilization, namespace, selector, v1.ResourceName(""))-->
						readyPodCount, unreadyPods, missingPods, ignoredPods := groupPods(podList, metrics, resource, c.cpuInitializationPeriod, c.delayOfInitialReadinessStatus)
						removeMetricsForPods(metrics, ignoredPods)
						removeMetricsForPods(metrics, unreadyPods)
						usageRatio, utilization := metricsclient.GetMetricUtilizationRatio(metrics, targetUtilization) // 计算目标utilization与当前utilization的比值
						newReplicas := int32(math.Ceil(newUsageRatio * float64(len(metrics)))) // len(metrics)=有效pod数量
		case autoscalingv2.ResourceMetricSourceType:
		case autoscalingv2.ContainerResourceMetricSourceType:
		case autoscalingv2.ExternalMetricSourceType:
			a.computeStatusForExternalMetric(specReplicas, statusReplicas, spec, hpa, selector, status)-->
				a.replicaCalc.GetExternalPerPodMetricReplicas(statusReplicas, metricSpec.External.Target.AverageValue.MilliValue(), metricSpec.External.Metric.Name, hpa.Namespace, metricSpec.External.Metric.Selector)
					metrics, timestamp, err := c.metricsClient.GetExternalMetric(metricName, namespace, metricLabelSelector)
		}
	desiredReplicas = a.normalizeDesiredReplicasWithBehaviors(hpa, key, currentReplicas, desiredReplicas, minReplicas)
	a.updateStatusIfNeeded(hpaStatusOriginal, hpa)