Example #1
0
// ScaleUp tries to scale the cluster up. Return true if it found a way to increase the size,
// false if it didn't and error if an error occured.
func ScaleUp(unschedulablePods []*kube_api.Pod, nodes []*kube_api.Node, migConfigs []*config.MigConfig,
	gceManager *gce.GceManager, kubeClient *kube_client.Client,
	predicateChecker *simulator.PredicateChecker, recorder kube_record.EventRecorder) (bool, error) {

	// From now on we only care about unschedulable pods that were marked after the newest
	// node became available for the scheduler.
	if len(unschedulablePods) == 0 {
		glog.V(1).Info("No unschedulable pods")
		return false, nil
	}

	for _, pod := range unschedulablePods {
		glog.V(1).Infof("Pod %s/%s is unschedulable", pod.Namespace, pod.Name)
	}

	expansionOptions := make([]ExpansionOption, 0)
	nodeInfos, err := GetNodeInfosForMigs(nodes, gceManager, kubeClient)
	if err != nil {
		return false, fmt.Errorf("failed to build node infors for migs: %v", err)
	}

	podsRemainUnshedulable := make(map[*kube_api.Pod]struct{})
	for _, migConfig := range migConfigs {

		currentSize, err := gceManager.GetMigSize(migConfig)
		if err != nil {
			glog.Errorf("Failed to get MIG size: %v", err)
			continue
		}
		if currentSize >= int64(migConfig.MaxSize) {
			// skip this mig.
			glog.V(4).Infof("Skipping MIG %s - max size reached", migConfig.Url())
			continue
		}

		option := ExpansionOption{
			migConfig: migConfig,
			estimator: estimator.NewBasicNodeEstimator(),
		}
		migHelpsSomePods := false

		nodeInfo, found := nodeInfos[migConfig.Url()]
		if !found {
			glog.Errorf("No node info for: %s", migConfig.Url())
			continue
		}

		for _, pod := range unschedulablePods {
			err = predicateChecker.CheckPredicates(pod, nodeInfo)
			if err == nil {
				migHelpsSomePods = true
				option.estimator.Add(pod)
			} else {
				glog.V(2).Infof("Scale-up predicate failed: %v", err)
				podsRemainUnshedulable[pod] = struct{}{}
			}
		}
		if migHelpsSomePods {
			expansionOptions = append(expansionOptions, option)
		}
	}

	// Pick some expansion option.
	bestOption := BestExpansionOption(expansionOptions)
	if bestOption != nil && bestOption.estimator.GetCount() > 0 {
		glog.V(1).Infof("Best option to resize: %s", bestOption.migConfig.Url())
		nodeInfo, found := nodeInfos[bestOption.migConfig.Url()]
		if !found {
			return false, fmt.Errorf("no sample node for: %s", bestOption.migConfig.Url())

		}
		node := nodeInfo.Node()
		estimate, report := bestOption.estimator.Estimate(node)
		glog.V(1).Info(bestOption.estimator.GetDebug())
		glog.V(1).Info(report)
		glog.V(1).Infof("Estimated %d nodes needed in %s", estimate, bestOption.migConfig.Url())

		currentSize, err := gceManager.GetMigSize(bestOption.migConfig)
		if err != nil {
			return false, fmt.Errorf("failed to get MIG size: %v", err)
		}
		newSize := currentSize + int64(estimate)
		if newSize >= int64(bestOption.migConfig.MaxSize) {
			glog.V(1).Infof("Capping size to MAX (%d)", bestOption.migConfig.MaxSize)
			newSize = int64(bestOption.migConfig.MaxSize)
		}
		glog.V(1).Infof("Setting %s size to %d", bestOption.migConfig.Url(), newSize)

		if err := gceManager.SetMigSize(bestOption.migConfig, newSize); err != nil {
			return false, fmt.Errorf("failed to set MIG size: %v", err)
		}

		for pod := range bestOption.estimator.FittingPods {
			recorder.Eventf(pod, kube_api.EventTypeNormal, "TriggeredScaleUp",
				"pod triggered scale-up, mig: %s, sizes (current/new): %d/%d", bestOption.migConfig.Name, currentSize, newSize)
		}

		return true, nil
	}
	for pod := range podsRemainUnshedulable {
		recorder.Event(pod, kube_api.EventTypeNormal, "NotTriggerScaleUp",
			"pod didn't trigger scale-up (it wouldn't fit if a new node is added)")
	}

	return false, nil
}