scheduler: return UnschedulableAndUnresolvable when node capacity is insufficient

Currently, the NodeResourcesFit plugin always returns Unschedulable when a pod's resource requests exceed a node's available resources. However, when a pod's requests exceed the node's total allocatable, preemption cannot help since even an empty node would not have enough resources. This change modifies the NodeResourcesFit plugin to return UnschedulableAndUnresolvable when a pod's resource requests exceed the node's total allocatable. This helps optimize the scheduling process in large clusters by: 1. Reducing the number of candidate nodes that need to be considered for preemption 2. Providing clearer feedback about unresolvable resource constraints 3. Improving scheduling performance by avoiding unnecessary preemption calculations The change is particularly beneficial in heterogeneous clusters where node sizes vary significantly, as it helps quickly identify nodes that are fundamentally too small for certain pods. Fixes https://github.com/kubernetes/kubernetes/issues/131310 Co-authored-by: Kensei Nakada <handbomusic@gmail.com>
2026-07-18 04:54:54 +00:00 · 2025-04-17 18:01:03 +08:00
parent b53b9fb557
commit f63702de0f
3 changed files with 44 additions and 30 deletions
--- a/pkg/scheduler/framework/plugins/noderesources/fit.go
+++ b/pkg/scheduler/framework/plugins/noderesources/fit.go
@@ -463,10 +463,16 @@ func (f *Fit) Filter(ctx context.Context, cycleState *framework.CycleState, pod
 	if len(insufficientResources) != 0 {
 		// We will keep all failure reasons.
 		failureReasons := make([]string, 0, len(insufficientResources))
+		statusCode := framework.Unschedulable
 		for i := range insufficientResources {
 			failureReasons = append(failureReasons, insufficientResources[i].Reason)
+
+			if insufficientResources[i].Unresolvable {
+				statusCode = framework.UnschedulableAndUnresolvable
+			}
 		}
-		return framework.NewStatus(framework.Unschedulable, failureReasons...)
+
+		return framework.NewStatus(statusCode, failureReasons...)
 	}
 	return nil
 }
@@ -489,6 +495,9 @@ type InsufficientResource struct {
 	Requested int64
 	Used      int64
 	Capacity  int64
+	// Unresolvable indicates whether this node could be schedulable for the pod by the preemption,
+	// which is determined by comparing the node's size and the pod's request.
+	Unresolvable bool
 }

 // Fits checks if node have enough resources to host the pod.
@@ -524,6 +533,7 @@ func fitsRequest(podRequest *preFilterState, nodeInfo *framework.NodeInfo, ignor
 			Requested:    podRequest.MilliCPU,
 			Used:         nodeInfo.Requested.MilliCPU,
 			Capacity:     nodeInfo.Allocatable.MilliCPU,
+			Unresolvable: podRequest.MilliCPU > nodeInfo.Allocatable.MilliCPU,
 		})
 	}
 	if podRequest.Memory > 0 && podRequest.Memory > (nodeInfo.Allocatable.Memory-nodeInfo.Requested.Memory) {
@@ -533,6 +543,7 @@ func fitsRequest(podRequest *preFilterState, nodeInfo *framework.NodeInfo, ignor
 			Requested:    podRequest.Memory,
 			Used:         nodeInfo.Requested.Memory,
 			Capacity:     nodeInfo.Allocatable.Memory,
+			Unresolvable: podRequest.Memory > nodeInfo.Allocatable.Memory,
 		})
 	}
 	if podRequest.EphemeralStorage > 0 &&
@@ -543,6 +554,7 @@ func fitsRequest(podRequest *preFilterState, nodeInfo *framework.NodeInfo, ignor
 			Requested:    podRequest.EphemeralStorage,
 			Used:         nodeInfo.Requested.EphemeralStorage,
 			Capacity:     nodeInfo.Allocatable.EphemeralStorage,
+			Unresolvable: podRequest.EphemeralStorage > nodeInfo.Allocatable.EphemeralStorage,
 		})
 	}

@@ -571,6 +583,7 @@ func fitsRequest(podRequest *preFilterState, nodeInfo *framework.NodeInfo, ignor
 				Requested:    podRequest.ScalarResources[rName],
 				Used:         nodeInfo.Requested.ScalarResources[rName],
 				Capacity:     nodeInfo.Allocatable.ScalarResources[rName],
+				Unresolvable: rQuant > nodeInfo.Allocatable.ScalarResources[rName],
 			})
 		}
 	}
--- a/pkg/scheduler/framework/plugins/noderesources/fit_test.go
+++ b/pkg/scheduler/framework/plugins/noderesources/fit_test.go
@@ -268,9 +268,9 @@ func TestEnoughRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 0, Memory: 0, ScalarResources: map[v1.ResourceName]int64{extendedResourceA: 0}})),
 			name:       "extended resource capacity enforced",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(extendedResourceA)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(extendedResourceA)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: extendedResourceA, Reason: getErrReason(extendedResourceA), Requested: 10, Used: 0, Capacity: 5},
+				{ResourceName: extendedResourceA, Reason: getErrReason(extendedResourceA), Requested: 10, Used: 0, Capacity: 5, Unresolvable: true},
 			},
 		},
 		{
@@ -279,9 +279,9 @@ func TestEnoughRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 0, Memory: 0, ScalarResources: map[v1.ResourceName]int64{extendedResourceA: 0}})),
 			name:       "extended resource capacity enforced for init container",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(extendedResourceA)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(extendedResourceA)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: extendedResourceA, Reason: getErrReason(extendedResourceA), Requested: 10, Used: 0, Capacity: 5},
+				{ResourceName: extendedResourceA, Reason: getErrReason(extendedResourceA), Requested: 10, Used: 0, Capacity: 5, Unresolvable: true},
 			},
 		},
 		{
@@ -313,9 +313,9 @@ func TestEnoughRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 0, Memory: 0, ScalarResources: map[v1.ResourceName]int64{extendedResourceA: 2}})),
 			name:       "extended resource allocatable enforced for multiple containers",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(extendedResourceA)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(extendedResourceA)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: extendedResourceA, Reason: getErrReason(extendedResourceA), Requested: 6, Used: 2, Capacity: 5},
+				{ResourceName: extendedResourceA, Reason: getErrReason(extendedResourceA), Requested: 6, Used: 2, Capacity: 5, Unresolvable: true},
 			},
 		},
 		{
@@ -334,9 +334,9 @@ func TestEnoughRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 0, Memory: 0, ScalarResources: map[v1.ResourceName]int64{extendedResourceA: 2}})),
 			name:       "extended resource allocatable enforced for multiple init containers",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(extendedResourceA)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(extendedResourceA)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: extendedResourceA, Reason: getErrReason(extendedResourceA), Requested: 6, Used: 2, Capacity: 5},
+				{ResourceName: extendedResourceA, Reason: getErrReason(extendedResourceA), Requested: 6, Used: 2, Capacity: 5, Unresolvable: true},
 			},
 		},
 		{
@@ -345,9 +345,9 @@ func TestEnoughRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 0, Memory: 0})),
 			name:       "extended resource allocatable enforced for unknown resource",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(extendedResourceB)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(extendedResourceB)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: extendedResourceB, Reason: getErrReason(extendedResourceB), Requested: 1, Used: 0, Capacity: 0},
+				{ResourceName: extendedResourceB, Reason: getErrReason(extendedResourceB), Requested: 1, Used: 0, Capacity: 0, Unresolvable: true},
 			},
 		},
 		{
@@ -356,9 +356,9 @@ func TestEnoughRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 0, Memory: 0})),
 			name:       "extended resource allocatable enforced for unknown resource for init container",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(extendedResourceB)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(extendedResourceB)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: extendedResourceB, Reason: getErrReason(extendedResourceB), Requested: 1, Used: 0, Capacity: 0},
+				{ResourceName: extendedResourceB, Reason: getErrReason(extendedResourceB), Requested: 1, Used: 0, Capacity: 0, Unresolvable: true},
 			},
 		},
 		{
@@ -367,9 +367,9 @@ func TestEnoughRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 0, Memory: 0})),
 			name:       "kubernetes.io resource capacity enforced",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(kubernetesIOResourceA)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(kubernetesIOResourceA)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: kubernetesIOResourceA, Reason: getErrReason(kubernetesIOResourceA), Requested: 10, Used: 0, Capacity: 0},
+				{ResourceName: kubernetesIOResourceA, Reason: getErrReason(kubernetesIOResourceA), Requested: 10, Used: 0, Capacity: 0, Unresolvable: true},
 			},
 		},
 		{
@@ -378,9 +378,9 @@ func TestEnoughRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 0, Memory: 0})),
 			name:       "kubernetes.io resource capacity enforced for init container",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(kubernetesIOResourceB)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(kubernetesIOResourceB)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: kubernetesIOResourceB, Reason: getErrReason(kubernetesIOResourceB), Requested: 10, Used: 0, Capacity: 0},
+				{ResourceName: kubernetesIOResourceB, Reason: getErrReason(kubernetesIOResourceB), Requested: 10, Used: 0, Capacity: 0, Unresolvable: true},
 			},
 		},
 		{
@@ -389,9 +389,9 @@ func TestEnoughRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 0, Memory: 0, ScalarResources: map[v1.ResourceName]int64{hugePageResourceA: 0}})),
 			name:       "hugepages resource capacity enforced",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(hugePageResourceA)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(hugePageResourceA)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: hugePageResourceA, Reason: getErrReason(hugePageResourceA), Requested: 10, Used: 0, Capacity: 5},
+				{ResourceName: hugePageResourceA, Reason: getErrReason(hugePageResourceA), Requested: 10, Used: 0, Capacity: 5, Unresolvable: true},
 			},
 		},
 		{
@@ -400,9 +400,9 @@ func TestEnoughRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 0, Memory: 0, ScalarResources: map[v1.ResourceName]int64{hugePageResourceA: 0}})),
 			name:       "hugepages resource capacity enforced for init container",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(hugePageResourceA)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(hugePageResourceA)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: hugePageResourceA, Reason: getErrReason(hugePageResourceA), Requested: 10, Used: 0, Capacity: 5},
+				{ResourceName: hugePageResourceA, Reason: getErrReason(hugePageResourceA), Requested: 10, Used: 0, Capacity: 5, Unresolvable: true},
 			},
 		},
 		{
@@ -412,9 +412,9 @@ func TestEnoughRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 0, Memory: 0, ScalarResources: map[v1.ResourceName]int64{hugePageResourceA: 2}})),
 			name:       "hugepages resource allocatable enforced for multiple containers",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(hugePageResourceA)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(hugePageResourceA)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: hugePageResourceA, Reason: getErrReason(hugePageResourceA), Requested: 6, Used: 2, Capacity: 5},
+				{ResourceName: hugePageResourceA, Reason: getErrReason(hugePageResourceA), Requested: 6, Used: 2, Capacity: 5, Unresolvable: true},
 			},
 		},
 		{
@@ -462,14 +462,15 @@ func TestEnoughRequests(t *testing.T) {
 				IgnoredResourceGroups: []string{"example.com"},
 			},
 			name:       "skip checking ignored extended resource via resource groups",
-			wantStatus: framework.NewStatus(framework.Unschedulable, fmt.Sprintf("Insufficient %v", kubernetesIOResourceA)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(kubernetesIOResourceA)),
 			wantInsufficientResources: []InsufficientResource{
 				{
 					ResourceName: kubernetesIOResourceA,
-					Reason:       fmt.Sprintf("Insufficient %v", kubernetesIOResourceA),
+					Reason:       getErrReason(kubernetesIOResourceA),
 					Requested:    1,
 					Used:         0,
 					Capacity:     0,
+					Unresolvable: true,
 				},
 			},
 		},
@@ -577,9 +578,9 @@ func TestEnoughRequests(t *testing.T) {
 			),
 			nodeInfo:   framework.NewNodeInfo(),
 			name:       "pod-level hugepages resource not fit",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(hugePageResourceA)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(hugePageResourceA)),
 			wantInsufficientResources: []InsufficientResource{
-				{ResourceName: hugePageResourceA, Reason: getErrReason(hugePageResourceA), Requested: 10, Used: 0, Capacity: 5},
+				{ResourceName: hugePageResourceA, Reason: getErrReason(hugePageResourceA), Requested: 10, Used: 0, Capacity: 5, Unresolvable: true},
 			},
 		},
 		{
@@ -736,7 +737,7 @@ func TestStorageRequests(t *testing.T) {
 			nodeInfo: framework.NewNodeInfo(
 				newResourcePod(framework.Resource{MilliCPU: 2, Memory: 2})),
 			name:       "storage ephemeral local storage request exceeds allocatable",
-			wantStatus: framework.NewStatus(framework.Unschedulable, getErrReason(v1.ResourceEphemeralStorage)),
+			wantStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(v1.ResourceEphemeralStorage)),
 		},
 		{
 			pod: newResourceInitPod(newResourcePod(framework.Resource{EphemeralStorage: 5})),
@@ -857,7 +858,7 @@ func TestRestartableInitContainers(t *testing.T) {
 				&v1.ResourceList{v1.ResourceCPU: *resource.NewMilliQuantity(1, resource.DecimalSI)},
 				&v1.ResourceList{v1.ResourceCPU: *resource.NewMilliQuantity(2, resource.DecimalSI)},
 			),
-			wantFilterStatus: framework.NewStatus(framework.Unschedulable, "Insufficient cpu"),
+			wantFilterStatus: framework.NewStatus(framework.UnschedulableAndUnresolvable, getErrReason(v1.ResourceCPU)),
 		},
 	}

--- a/pkg/scheduler/schedule_one_test.go
+++ b/pkg/scheduler/schedule_one_test.go
@@ -1477,7 +1477,7 @@ func TestSchedulerFailedSchedulingReasons(t *testing.T) {
 	failedNodeStatues := framework.NewDefaultNodeToStatus()
 	for _, node := range nodes {
 		failedNodeStatues.Set(node.Name, framework.NewStatus(
-			framework.Unschedulable,
+			framework.UnschedulableAndUnresolvable,
 			fmt.Sprintf("Insufficient %v", v1.ResourceCPU),
 			fmt.Sprintf("Insufficient %v", v1.ResourceMemory),
 		).WithPlugin(noderesources.Name))