When pod listing, filter out unschedulable and scheduler unprocessed pods not in the list of allowed schedulers

cluster-autoscaler/config/autoscaling_options.go

@@ -294,6 +294,8 @@ type AutoscalingOptions struct {
 	DynamicNodeDeleteDelayAfterTaintEnabled bool
 	// BypassedSchedulers are used to specify which schedulers to bypass their processing
 	BypassedSchedulers map[string]bool
+	// AllowedSchedulers when specified CA will proceed only with pods that are targeting allowed schedulers from unschedulable pods and unprocessed pods by BypassedSchedulers.
+	AllowedSchedulers map[string]bool
 	// ProvisioningRequestEnabled tells if CA processes ProvisioningRequest.
 	ProvisioningRequestEnabled bool
 	// AsyncNodeGroupsEnabled tells if CA creates/deletes node groups asynchronously.

cluster-autoscaler/config/flags/flags.go

@@ -208,6 +208,7 @@ var (
 	forceDaemonSets                         = flag.Bool("force-ds", false, "Blocks scale-up of node groups too small for all suitable Daemon Sets pods.")
 	dynamicNodeDeleteDelayAfterTaintEnabled = flag.Bool("dynamic-node-delete-delay-after-taint-enabled", false, "Enables dynamic adjustment of NodeDeleteDelayAfterTaint based of the latency between CA and api-server")
 	bypassedSchedulers                      = pflag.StringSlice("bypassed-scheduler-names", []string{}, "Names of schedulers to bypass. If set to non-empty value, CA will not wait for pods to reach a certain age before triggering a scale-up.")
+	allowedSchedulers                       = pflag.StringSlice("allowed-scheduler-names", []string{}, "If set to non-empty value, CA will proceed only with pods targeting schedulers in the list, from the list of unschedulable and scheduler unprocessed pods")
 	drainPriorityConfig                     = flag.String("drain-priority-config", "",
 		"List of ',' separated pairs (priority:terminationGracePeriodSeconds) of integers separated by ':' enables priority evictor. Priority evictor groups pods into priority groups based on pod priority and evict pods in the ascending order of group priorities"+
 			"--max-graceful-termination-sec flag should not be set when this flag is set. Not setting this flag will use unordered evictor by default."+
@@ -395,7 +396,8 @@ func createAutoscalingOptions() config.AutoscalingOptions {
 			MaxFreeDifferenceRatio:           *maxFreeDifferenceRatio,
 		},
 		DynamicNodeDeleteDelayAfterTaintEnabled:      *dynamicNodeDeleteDelayAfterTaintEnabled,
-		BypassedSchedulers:                           scheduler_util.GetBypassedSchedulersMap(*bypassedSchedulers),
+		BypassedSchedulers:                           scheduler_util.SchedulersMap(*bypassedSchedulers),
+		AllowedSchedulers:                            parseAllowedSchedulers(*allowedSchedulers, *bypassedSchedulers),
 		ProvisioningRequestEnabled:                   *provisioningRequestsEnabled,
 		AsyncNodeGroupsEnabled:                       *asyncNodeGroupsEnabled,
 		ProvisioningRequestInitialBackoffTime:        *provisioningRequestInitialBackoffTime,
@@ -542,3 +544,18 @@ func parseShutdownGracePeriodsAndPriorities(priorityGracePeriodStr string) []kub
 	}
 	return priorityGracePeriodMap
 }
+
+func parseAllowedSchedulers(allowedSchedulers, bypassedSchedulers []string) map[string]bool {
+	allowedSchedulersMap := scheduler_util.SchedulersMap(allowedSchedulers)
+	if len(allowedSchedulers) == 0 {
+		return allowedSchedulersMap
+	}
+	bypassedSchedulersMap := scheduler_util.SchedulersMap(bypassedSchedulers)
+
+	for scheduler := range bypassedSchedulersMap {
+		if found := allowedSchedulersMap[scheduler]; !found {
+			klog.Fatalf("Invalid configuration. --bypassed-scheduler-names should be a subset of --allowed-scheduler-names. %s not included in --allowed-scheduler-names", scheduler)
+		}
+	}
+	return allowedSchedulersMap
+}

cluster-autoscaler/core/static_autoscaler.go

@@ -292,7 +292,7 @@ func (a *StaticAutoscaler) RunOnce(currentTime time.Time) caerrors.AutoscalerErr
 		return err
 	}
 
-	podsBySchedulability, err := listPods(podLister, a.BypassedSchedulers)
+	podsBySchedulability, err := listPods(podLister, a.BypassedSchedulers, a.AllowedSchedulers)
 	if err != nil {
 		return caerrors.ToAutoscalerError(caerrors.ApiCallError, err)
 	}
@@ -1156,18 +1156,23 @@ func nodeNames(ns []*apiv1.Node) []string {
 	return names
 }
 
-func listPods(podLister kube_util.PodLister, bypassedSchedulers map[string]bool) (podsBySchedulability kube_util.PodsBySchedulability, err error) {
+func listPods(podLister kube_util.PodLister, bypassedSchedulers, allowedSchedulers map[string]bool) (podsBySchedulability kube_util.PodsBySchedulability, err error) {
 	pods, err := podLister.List()
 	if err != nil {
 		klog.Errorf("Failed to list pods: %v", err)
 		return podsBySchedulability, err
 	}
+	initialPodCount := len(pods)
+	if len(allowedSchedulers) > 0 {
+		pods = kube_util.FilterOutPodsByScheduler(pods, allowedSchedulers)
+	}
 	podsBySchedulability = kube_util.ArrangePodsBySchedulability(pods, bypassedSchedulers)
 	// Skip logging in case of the boring scenario, when all pods are scheduled.
 	if len(pods) != len(podsBySchedulability.Scheduled) {
+		ignoredDueToDisallowed := initialPodCount - len(pods)
 		ignored := len(pods) - len(podsBySchedulability.Scheduled) - len(podsBySchedulability.Unschedulable) - len(podsBySchedulability.Unprocessed)
-		klog.Infof("Found %d pods in the cluster: %d scheduled, %d unschedulable, %d unprocessed by scheduler, %d ignored (most likely using custom scheduler)",
-			len(pods), len(podsBySchedulability.Scheduled), len(podsBySchedulability.Unschedulable), len(podsBySchedulability.Unprocessed), ignored)
+		klog.Infof("Found %d pods in the cluster: %d scheduled, %d unschedulable, %d unprocessed by scheduler, %d ignored by allowed schedulers (most likely using custom scheduler), %d ignored due to dissallowed schedulers",
+			initialPodCount, len(podsBySchedulability.Scheduled), len(podsBySchedulability.Unschedulable), len(podsBySchedulability.Unprocessed), ignored, ignoredDueToDisallowed)
 	}
 	return
 }

cluster-autoscaler/core/static_autoscaler_test.go

@@ -1473,7 +1473,7 @@ func TestStaticAutoscalerRunOnceWithBypassedSchedulers(t *testing.T) {
 		MaxNodesTotal:    10,
 		MaxCoresTotal:    10,
 		MaxMemoryTotal:   100000,
-		BypassedSchedulers: scheduler.GetBypassedSchedulersMap([]string{
+		BypassedSchedulers: scheduler.SchedulersMap([]string{
 			apiv1.DefaultSchedulerName,
 			bypassedScheduler,
 		}),

cluster-autoscaler/utils/kubernetes/listers.go

@@ -200,6 +200,17 @@ func ArrangePodsBySchedulability(allPods []*apiv1.Pod, bypassedSchedulers map[st
 	return
 }
 
+// FilterOutPodsByScheduler is a helper method that filters out pods not in the given set of allowed schedulers.
+func FilterOutPodsByScheduler(allPods []*apiv1.Pod, allowedSchedulers map[string]bool) []*apiv1.Pod {
+	var remainingPods []*apiv1.Pod
+	for _, pod := range allPods {
+		if keep := allowedSchedulers[pod.Spec.SchedulerName]; keep {
+			remainingPods = append(remainingPods, pod)
+		}
+	}
+	return remainingPods
+}
+
 // SchedulingGatedPods is a helper method that returns all pods which has scheduling gate
 // SchedulingGated pods are not scheduled nor deleted by the implementation and are not unschedulable nor unprocessed by definition
 func SchedulingGatedPods(allPods []*apiv1.Pod) []*apiv1.Pod {

cluster-autoscaler/utils/scheduler/scheduler.go

@@ -126,15 +126,15 @@ func ConfigFromPath(path string) (*scheduler_config.KubeSchedulerConfiguration,
 	return cfgObj, nil
 }
 
-// GetBypassedSchedulersMap returns a map of scheduler names that should be bypassed as keys, and values are set to true
-// Also sets "" (empty string) to true if default scheduler is bypassed
-func GetBypassedSchedulersMap(bypassedSchedulers []string) map[string]bool {
-	bypassedSchedulersMap := make(map[string]bool, len(bypassedSchedulers))
-	for _, scheduler := range bypassedSchedulers {
-		bypassedSchedulersMap[scheduler] = true
+// SchedulersMap returns a map of scheduler names as keys, and values are set to true
+// Also sets "" (empty string) to true if default scheduler is in the list
+func SchedulersMap(schedulers []string) map[string]bool {
+	schedulersMap := make(map[string]bool, len(schedulers))
+	for _, scheduler := range schedulers {
+		schedulersMap[scheduler] = true
 	}
-	if canBypass := bypassedSchedulersMap[apiv1.DefaultSchedulerName]; canBypass {
-		bypassedSchedulersMap[""] = true
+	if found := schedulersMap[apiv1.DefaultSchedulerName]; found {
+		schedulersMap[""] = true
 	}
-	return bypassedSchedulersMap
+	return schedulersMap
 }