resource_allocation.go

Documentation: k8s.io/kubernetes/pkg/scheduler/framework/plugins/noderesources

     1  /*
     2  Copyright 2017 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package noderesources
    18  
    19  import (
    20  	"context"
    21  
    22  	v1 "k8s.io/api/core/v1"
    23  	"k8s.io/apimachinery/pkg/api/resource"
    24  	utilfeature "k8s.io/apiserver/pkg/util/feature"
    25  	"k8s.io/klog/v2"
    26  
    27  	resourcehelper "k8s.io/kubernetes/pkg/api/v1/resource"
    28  	"k8s.io/kubernetes/pkg/features"
    29  	"k8s.io/kubernetes/pkg/scheduler/apis/config"
    30  	"k8s.io/kubernetes/pkg/scheduler/framework"
    31  	schedutil "k8s.io/kubernetes/pkg/scheduler/util"
    32  )
    33  
    34  // scorer is decorator for resourceAllocationScorer
    35  type scorer func(args *config.NodeResourcesFitArgs) *resourceAllocationScorer
    36  
    37  // resourceAllocationScorer contains information to calculate resource allocation score.
    38  type resourceAllocationScorer struct {
    39  	Name string
    40  	// used to decide whether to use Requested or NonZeroRequested for
    41  	// cpu and memory.
    42  	useRequested bool
    43  	scorer       func(requested, allocable []int64) int64
    44  	resources    []config.ResourceSpec
    45  }
    46  
    47  // score will use `scorer` function to calculate the score.
    48  func (r *resourceAllocationScorer) score(
    49  	ctx context.Context,
    50  	pod *v1.Pod,
    51  	nodeInfo *framework.NodeInfo,
    52  	podRequests []int64) (int64, *framework.Status) {
    53  	logger := klog.FromContext(ctx)
    54  	node := nodeInfo.Node()
    55  
    56  	// resources not set, nothing scheduled,
    57  	if len(r.resources) == 0 {
    58  		return 0, framework.NewStatus(framework.Error, "resources not found")
    59  	}
    60  
    61  	requested := make([]int64, len(r.resources))
    62  	allocatable := make([]int64, len(r.resources))
    63  	for i := range r.resources {
    64  		alloc, req := r.calculateResourceAllocatableRequest(logger, nodeInfo, v1.ResourceName(r.resources[i].Name), podRequests[i])
    65  		// Only fill the extended resource entry when it's non-zero.
    66  		if alloc == 0 {
    67  			continue
    68  		}
    69  		allocatable[i] = alloc
    70  		requested[i] = req
    71  	}
    72  
    73  	score := r.scorer(requested, allocatable)
    74  
    75  	if loggerV := logger.V(10); loggerV.Enabled() { // Serializing these maps is costly.
    76  		loggerV.Info("Listed internal info for allocatable resources, requested resources and score", "pod",
    77  			klog.KObj(pod), "node", klog.KObj(node), "resourceAllocationScorer", r.Name,
    78  			"allocatableResource", allocatable, "requestedResource", requested, "resourceScore", score,
    79  		)
    80  	}
    81  
    82  	return score, nil
    83  }
    84  
    85  // calculateResourceAllocatableRequest returns 2 parameters:
    86  // - 1st param: quantity of allocatable resource on the node.
    87  // - 2nd param: aggregated quantity of requested resource on the node.
    88  // Note: if it's an extended resource, and the pod doesn't request it, (0, 0) is returned.
    89  func (r *resourceAllocationScorer) calculateResourceAllocatableRequest(logger klog.Logger, nodeInfo *framework.NodeInfo, resource v1.ResourceName, podRequest int64) (int64, int64) {
    90  	requested := nodeInfo.NonZeroRequested
    91  	if r.useRequested {
    92  		requested = nodeInfo.Requested
    93  	}
    94  
    95  	// If it's an extended resource, and the pod doesn't request it. We return (0, 0)
    96  	// as an implication to bypass scoring on this resource.
    97  	if podRequest == 0 && schedutil.IsScalarResourceName(resource) {
    98  		return 0, 0
    99  	}
   100  	switch resource {
   101  	case v1.ResourceCPU:
   102  		return nodeInfo.Allocatable.MilliCPU, (requested.MilliCPU + podRequest)
   103  	case v1.ResourceMemory:
   104  		return nodeInfo.Allocatable.Memory, (requested.Memory + podRequest)
   105  	case v1.ResourceEphemeralStorage:
   106  		return nodeInfo.Allocatable.EphemeralStorage, (nodeInfo.Requested.EphemeralStorage + podRequest)
   107  	default:
   108  		if _, exists := nodeInfo.Allocatable.ScalarResources[resource]; exists {
   109  			return nodeInfo.Allocatable.ScalarResources[resource], (nodeInfo.Requested.ScalarResources[resource] + podRequest)
   110  		}
   111  	}
   112  	logger.V(10).Info("Requested resource is omitted for node score calculation", "resourceName", resource)
   113  	return 0, 0
   114  }
   115  
   116  // calculatePodResourceRequest returns the total non-zero requests. If Overhead is defined for the pod
   117  // the Overhead is added to the result.
   118  func (r *resourceAllocationScorer) calculatePodResourceRequest(pod *v1.Pod, resourceName v1.ResourceName) int64 {
   119  
   120  	opts := resourcehelper.PodResourcesOptions{
   121  		InPlacePodVerticalScalingEnabled: utilfeature.DefaultFeatureGate.Enabled(features.InPlacePodVerticalScaling),
   122  	}
   123  	if !r.useRequested {
   124  		opts.NonMissingContainerRequests = v1.ResourceList{
   125  			v1.ResourceCPU:    *resource.NewMilliQuantity(schedutil.DefaultMilliCPURequest, resource.DecimalSI),
   126  			v1.ResourceMemory: *resource.NewQuantity(schedutil.DefaultMemoryRequest, resource.DecimalSI),
   127  		}
   128  	}
   129  
   130  	requests := resourcehelper.PodRequests(pod, opts)
   131  
   132  	quantity := requests[resourceName]
   133  	if resourceName == v1.ResourceCPU {
   134  		return quantity.MilliValue()
   135  	}
   136  	return quantity.Value()
   137  }
   138  
   139  func (r *resourceAllocationScorer) calculatePodResourceRequestList(pod *v1.Pod, resources []config.ResourceSpec) []int64 {
   140  	podRequests := make([]int64, len(resources))
   141  	for i := range resources {
   142  		podRequests[i] = r.calculatePodResourceRequest(pod, v1.ResourceName(resources[i].Name))
   143  	}
   144  	return podRequests
   145  }
   146
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