fix: calculate the overhead with the maximum value

charts/karpenter/values.yaml

@@ -64,7 +64,7 @@ controller:
     # -- The external kubernetes cluster id for new nodes to connect with.
     clusterID: ""
     # -- The VM memory overhead as a percent that will be subtracted from the total memory for all instance types. The value of `0.075` equals to 7.5%.
-    vmMemoryOverheadPercent: 0.075
+    vmMemoryOverheadPercent: 0.065
     # -- The maximum length of a batch window. The longer this is, the more pods we can consider for provisioning at one
     # time which usually results in fewer but larger nodes.
     batchMaxDuration: 10s

pkg/operator/operator.go

@@ -108,7 +108,7 @@ func NewOperator(ctx context.Context, operator *operator.Operator) (context.Cont
 
 	unavailableOfferingsCache := alicache.NewUnavailableOfferings()
 	instanceTypeProvider := instancetype.NewDefaultProvider(
-		*ecsClient.RegionId, ecsClient,
+		*ecsClient.RegionId, operator.GetClient(), ecsClient,
 		cache.New(alicache.InstanceTypesAndZonesTTL, alicache.DefaultCleanupInterval),
 		unavailableOfferingsCache,
 		pricingProvider, ackProvider)

pkg/operator/options/options.go

@@ -44,7 +44,7 @@ type Options struct {
 func (o *Options) AddFlags(fs *coreoptions.FlagSet) {
 	fs.StringVar(&o.ClusterID, "cluster-id", env.WithDefaultString("CLUSTER_ID", ""), "The external kubernetes cluster id for new nodes to connect with.")
 	// TODO: for different OS, the overhead is different, find a way to fix this.
-	fs.Float64Var(&o.VMMemoryOverheadPercent, "vm-memory-overhead-percent", utils.WithDefaultFloat64("VM_MEMORY_OVERHEAD_PERCENT", 0.075), "The VM memory overhead as a percent that will be subtracted from the total memory for all instance types.")
+	fs.Float64Var(&o.VMMemoryOverheadPercent, "vm-memory-overhead-percent", utils.WithDefaultFloat64("VM_MEMORY_OVERHEAD_PERCENT", 0.065), "The VM memory overhead as a percent that will be subtracted from the total memory for all instance types.")
 	fs.BoolVar(&o.Interruption, "interruption", env.WithDefaultBool("INTERRUPTION", true), "Enable interruption handling.")
 	fs.BoolVar(&o.TelemetryShare, "telemetry-share", env.WithDefaultBool("TELEMETRY_SHARE", true), "Enable telemetry sharing.")
 	fs.IntVar(&o.APGCreationQPS, "apg-qps", int(env.WithDefaultInt64("APG_CREATION_QPS", 100)), "The QPS limit for creating AutoProvisionGroup.")

pkg/providers/instancetype/instancetype.go

@@ -29,7 +29,9 @@ import (
 	"github.com/patrickmn/go-cache"
 	"github.com/samber/lo"
 	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
 	"k8s.io/apimachinery/pkg/util/sets"
+	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/log"
 	karpv1 "sigs.k8s.io/karpenter/pkg/apis/v1"
 	"sigs.k8s.io/karpenter/pkg/cloudprovider"
@@ -52,6 +54,7 @@ type Provider interface {
 
 type DefaultProvider struct {
 	region          string
+	kubeClient      client.Client
 	ecsClient       *ecsclient.Client
 	pricingProvider pricing.Provider
 	ackProvider     ack.Provider
@@ -77,10 +80,11 @@ type DefaultProvider struct {
 	instanceTypesOfferingsSeqNum uint64
 }
 
-func NewDefaultProvider(region string, ecsClient *ecsclient.Client,
+func NewDefaultProvider(region string, kubeClient client.Client, ecsClient *ecsclient.Client,
 	instanceTypesCache *cache.Cache, unavailableOfferingsCache *kcache.UnavailableOfferings,
 	pricingProvider pricing.Provider, ackProvider ack.Provider) *DefaultProvider {
 	return &DefaultProvider{
+		kubeClient:             kubeClient,
 		ecsClient:              ecsClient,
 		region:                 region,
 		pricingProvider:        pricingProvider,
@@ -175,6 +179,11 @@ func (p *DefaultProvider) List(ctx context.Context, kc *v1alpha1.KubeletConfigur
 		return nil, fmt.Errorf("failed to get cluster CNI: %w", err)
 	}
 
+	nodeResourceOverhead, err := p.nodeOverhead(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get node resource overhead: %w", err)
+	}
+
 	result := lo.Map(p.instanceTypesInfo, func(i *ecsclient.DescribeInstanceTypesResponseBodyInstanceTypesInstanceType, _ int) *cloudprovider.InstanceType {
 		zoneData := lo.Map(allZones.UnsortedList(), func(zoneID string, _ int) ZoneData {
 			if !p.instanceTypesOfferings[lo.FromPtr(i.InstanceTypeId)].Has(zoneID) || !vSwitchsZones.Has(zoneID) {
@@ -194,7 +203,7 @@ func (p *DefaultProvider) List(ctx context.Context, kc *v1alpha1.KubeletConfigur
 		// so that Karpenter is able to cache the set of InstanceTypes based on values that alter the set of instance types
 		// !!! Important !!!
 		offers := p.createOfferings(ctx, *i.InstanceTypeId, zoneData)
-		return NewInstanceType(ctx, i, kc, p.region, nodeClass.Spec.SystemDisk, offers, clusterCNI)
+		return NewInstanceType(ctx, nodeResourceOverhead, i, kc, p.region, nodeClass.Spec.SystemDisk, offers, clusterCNI)
 	})
 
 	// Filter out nil values
@@ -204,6 +213,37 @@ func (p *DefaultProvider) List(ctx context.Context, kc *v1alpha1.KubeletConfigur
 	return result, nil
 }
 
+func (p *DefaultProvider) nodeOverhead(ctx context.Context) (corev1.ResourceList, error) {
+	var nodes corev1.NodeList
+	if err := p.kubeClient.List(ctx, &nodes); err != nil {
+		return corev1.ResourceList{}, err
+	}
+
+	// We do not sure how to calculate the overhead of the node, let's just use the maximum possible
+	// To avoid some loop node creation
+	maxCPUOverHead := int64(0)
+	maxMemoryOverHead := int64(0)
+	for _, node := range nodes.Items {
+		capacity := node.Status.Capacity
+		allocatable := node.Status.Allocatable
+
+		cpuOverHead := capacity.Cpu().MilliValue() - allocatable.Cpu().MilliValue()
+		memoryOverHead := capacity.Memory().Value() - allocatable.Memory().Value()
+
+		if cpuOverHead > maxCPUOverHead {
+			maxCPUOverHead = cpuOverHead
+		}
+		if memoryOverHead > maxMemoryOverHead {
+			maxMemoryOverHead = memoryOverHead
+		}
+	}
+
+	return corev1.ResourceList{
+		corev1.ResourceCPU:    *resource.NewMilliQuantity(maxCPUOverHead, resource.DecimalSI),
+		corev1.ResourceMemory: *resource.NewQuantity(maxMemoryOverHead, resource.DecimalSI),
+	}, nil
+}
+
 func (p *DefaultProvider) UpdateInstanceTypes(ctx context.Context) error {
 	// DO NOT REMOVE THIS LOCK ----------------------------------------------------------------------------
 	// We lock here so that multiple callers to getInstanceTypesOfferings do not result in cache misses and multiple

pkg/providers/instancetype/types.go

@@ -42,9 +42,6 @@ var (
 )
 
 const (
-	MemoryAvailable = "memory.available"
-	NodeFSAvailable = "nodefs.available"
-
 	GiBMiBRatio              = 1024
 	MiBByteRatio             = 1024 * 1024
 	TerwayMinENIRequirements = 11
@@ -60,7 +57,7 @@ type ZoneData struct {
 	Available bool
 }
 
-func NewInstanceType(ctx context.Context,
+func NewInstanceType(ctx context.Context, overhead corev1.ResourceList,
 	info *ecsclient.DescribeInstanceTypesResponseBodyInstanceTypesInstanceType,
 	kc *v1alpha1.KubeletConfiguration, region string, systemDisk *v1alpha1.SystemDisk,
 	offerings cloudprovider.Offerings, clusterCNI string) *cloudprovider.InstanceType {
@@ -74,9 +71,10 @@ func NewInstanceType(ctx context.Context,
 		Offerings:    offerings,
 		Capacity:     computeCapacity(ctx, info, kc.MaxPods, kc.PodsPerCore, systemDisk, clusterCNI),
 		Overhead: &cloudprovider.InstanceTypeOverhead{
-			KubeReserved:      kubeReservedResources(kc.KubeReserved),
-			SystemReserved:    systemReservedResources(kc.SystemReserved),
-			EvictionThreshold: evictionThreshold(memory(ctx, info), ephemeralStorage(systemDisk), kc.EvictionHard, kc.EvictionSoft),
+			// Follow overhead will be merged, so we can set only one overhead totally
+			KubeReserved:      overhead,
+			SystemReserved:    corev1.ResourceList{},
+			EvictionThreshold: corev1.ResourceList{},
 		},
 	}
 	if it.Requirements.Compatible(scheduling.NewRequirements(scheduling.NewRequirement(corev1.LabelOSStable, corev1.NodeSelectorOpIn, string(corev1.Windows)))) == nil {
@@ -178,62 +176,6 @@ func computeCapacity(ctx context.Context,
 	return resourceList
 }
 
-func kubeReservedResources(kubeReserved map[string]string) corev1.ResourceList {
-	resources := corev1.ResourceList{
-		// TODO: Following data is extract from real env
-		// Please check it more
-		corev1.ResourceMemory: resource.MustParse("447Mi"),
-		corev1.ResourceCPU:    resource.MustParse("35m"),
-	}
-
-	return lo.Assign(resources, lo.MapEntries(kubeReserved, func(k string, v string) (corev1.ResourceName, resource.Quantity) {
-		return corev1.ResourceName(k), resource.MustParse(v)
-	}))
-}
-
-func systemReservedResources(systemReserved map[string]string) corev1.ResourceList {
-	resources := corev1.ResourceList{
-		// TODO: Following data is extract from real env
-		// Please check it more
-		corev1.ResourceMemory: resource.MustParse("447Mi"),
-		corev1.ResourceCPU:    resource.MustParse("35m"),
-	}
-
-	return lo.Assign(resources, lo.MapEntries(systemReserved, func(k string, v string) (corev1.ResourceName, resource.Quantity) {
-		return corev1.ResourceName(k), resource.MustParse(v)
-	}))
-}
-
-func evictionThreshold(memory *resource.Quantity, storage *resource.Quantity, evictionHard map[string]string, evictionSoft map[string]string) corev1.ResourceList {
-	overhead := corev1.ResourceList{
-		// TODO: Following data is extract from real env
-		// Please check it more
-		corev1.ResourceMemory: resource.MustParse("300Mi"),
-	}
-
-	override := corev1.ResourceList{}
-	var evictionSignals []map[string]string
-	if evictionHard != nil {
-		evictionSignals = append(evictionSignals, evictionHard)
-	}
-	if evictionSoft != nil {
-		evictionSignals = append(evictionSignals, evictionSoft)
-	}
-
-	for _, m := range evictionSignals {
-		temp := corev1.ResourceList{}
-		if v, ok := m[MemoryAvailable]; ok {
-			temp[corev1.ResourceMemory] = computeEvictionSignal(*memory, v)
-		}
-		if v, ok := m[NodeFSAvailable]; ok {
-			temp[corev1.ResourceEphemeralStorage] = computeEvictionSignal(*storage, v)
-		}
-		override = resources.MaxResources(override, temp)
-	}
-	// Assign merges maps from left to right so overrides will always be taken last
-	return lo.Assign(overhead, override)
-}
-
 // computeEvictionSignal computes the resource quantity value for an eviction signal value, computed off the
 // base capacity value if the signal value is a percentage or as a resource quantity if the signal value isn't a percentage
 func computeEvictionSignal(capacity resource.Quantity, signalValue string) resource.Quantity {