255 lines
11 KiB
Go
255 lines
11 KiB
Go
/*
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Copyright 2014 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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// This is the default algorithm provider for the scheduler.
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package defaults
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import (
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"os"
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"strconv"
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metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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"k8s.io/apimachinery/pkg/util/sets"
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"k8s.io/kubernetes/pkg/api/v1"
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"k8s.io/kubernetes/pkg/cloudprovider/providers/aws"
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"k8s.io/kubernetes/plugin/pkg/scheduler/algorithm"
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"k8s.io/kubernetes/plugin/pkg/scheduler/algorithm/predicates"
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"k8s.io/kubernetes/plugin/pkg/scheduler/algorithm/priorities"
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"k8s.io/kubernetes/plugin/pkg/scheduler/core"
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"k8s.io/kubernetes/plugin/pkg/scheduler/factory"
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"github.com/golang/glog"
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)
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const (
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// GCE instances can have up to 16 PD volumes attached.
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DefaultMaxGCEPDVolumes = 16
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ClusterAutoscalerProvider = "ClusterAutoscalerProvider"
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StatefulSetKind = "StatefulSet"
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)
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func init() {
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// Register functions that extract metadata used by predicates and priorities computations.
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factory.RegisterPredicateMetadataProducerFactory(
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func(args factory.PluginFactoryArgs) algorithm.MetadataProducer {
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return predicates.NewPredicateMetadataFactory(args.PodLister)
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})
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factory.RegisterPriorityMetadataProducerFactory(
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func(args factory.PluginFactoryArgs) algorithm.MetadataProducer {
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return priorities.PriorityMetadata
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})
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// Registers algorithm providers. By default we use 'DefaultProvider', but user can specify one to be used
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// by specifying flag.
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factory.RegisterAlgorithmProvider(factory.DefaultProvider, defaultPredicates(), defaultPriorities())
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// Cluster autoscaler friendly scheduling algorithm.
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factory.RegisterAlgorithmProvider(ClusterAutoscalerProvider, defaultPredicates(),
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copyAndReplace(defaultPriorities(), "LeastRequestedPriority", "MostRequestedPriority"))
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// Registers predicates and priorities that are not enabled by default, but user can pick when creating his
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// own set of priorities/predicates.
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// PodFitsPorts has been replaced by PodFitsHostPorts for better user understanding.
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// For backwards compatibility with 1.0, PodFitsPorts is registered as well.
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factory.RegisterFitPredicate("PodFitsPorts", predicates.PodFitsHostPorts)
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// Fit is defined based on the absence of port conflicts.
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// This predicate is actually a default predicate, because it is invoked from
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// predicates.GeneralPredicates()
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factory.RegisterFitPredicate("PodFitsHostPorts", predicates.PodFitsHostPorts)
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// Fit is determined by resource availability.
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// This predicate is actually a default predicate, because it is invoked from
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// predicates.GeneralPredicates()
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factory.RegisterFitPredicate("PodFitsResources", predicates.PodFitsResources)
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// Fit is determined by the presence of the Host parameter and a string match
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// This predicate is actually a default predicate, because it is invoked from
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// predicates.GeneralPredicates()
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factory.RegisterFitPredicate("HostName", predicates.PodFitsHost)
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// Fit is determined by node selector query.
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factory.RegisterFitPredicate("MatchNodeSelector", predicates.PodSelectorMatches)
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// Use equivalence class to speed up predicates & priorities
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factory.RegisterGetEquivalencePodFunction(GetEquivalencePod)
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// ServiceSpreadingPriority is a priority config factory that spreads pods by minimizing
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// the number of pods (belonging to the same service) on the same node.
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// Register the factory so that it's available, but do not include it as part of the default priorities
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// Largely replaced by "SelectorSpreadPriority", but registered for backward compatibility with 1.0
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factory.RegisterPriorityConfigFactory(
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"ServiceSpreadingPriority",
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factory.PriorityConfigFactory{
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Function: func(args factory.PluginFactoryArgs) algorithm.PriorityFunction {
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return priorities.NewSelectorSpreadPriority(args.ServiceLister, algorithm.EmptyControllerLister{}, algorithm.EmptyReplicaSetLister{})
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},
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Weight: 1,
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},
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)
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// EqualPriority is a prioritizer function that gives an equal weight of one to all nodes
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// Register the priority function so that its available
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// but do not include it as part of the default priorities
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factory.RegisterPriorityFunction2("EqualPriority", core.EqualPriorityMap, nil, 1)
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// ImageLocalityPriority prioritizes nodes based on locality of images requested by a pod. Nodes with larger size
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// of already-installed packages required by the pod will be preferred over nodes with no already-installed
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// packages required by the pod or a small total size of already-installed packages required by the pod.
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factory.RegisterPriorityFunction2("ImageLocalityPriority", priorities.ImageLocalityPriorityMap, nil, 1)
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// Optional, cluster-autoscaler friendly priority function - give used nodes higher priority.
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factory.RegisterPriorityFunction2("MostRequestedPriority", priorities.MostRequestedPriorityMap, nil, 1)
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}
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func defaultPredicates() sets.String {
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return sets.NewString(
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// Fit is determined by volume zone requirements.
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factory.RegisterFitPredicateFactory(
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"NoVolumeZoneConflict",
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func(args factory.PluginFactoryArgs) algorithm.FitPredicate {
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return predicates.NewVolumeZonePredicate(args.PVInfo, args.PVCInfo)
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},
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),
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// Fit is determined by whether or not there would be too many AWS EBS volumes attached to the node
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factory.RegisterFitPredicateFactory(
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"MaxEBSVolumeCount",
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func(args factory.PluginFactoryArgs) algorithm.FitPredicate {
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// TODO: allow for generically parameterized scheduler predicates, because this is a bit ugly
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maxVols := getMaxVols(aws.DefaultMaxEBSVolumes)
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return predicates.NewMaxPDVolumeCountPredicate(predicates.EBSVolumeFilter, maxVols, args.PVInfo, args.PVCInfo)
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},
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),
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// Fit is determined by whether or not there would be too many GCE PD volumes attached to the node
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factory.RegisterFitPredicateFactory(
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"MaxGCEPDVolumeCount",
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func(args factory.PluginFactoryArgs) algorithm.FitPredicate {
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// TODO: allow for generically parameterized scheduler predicates, because this is a bit ugly
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maxVols := getMaxVols(DefaultMaxGCEPDVolumes)
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return predicates.NewMaxPDVolumeCountPredicate(predicates.GCEPDVolumeFilter, maxVols, args.PVInfo, args.PVCInfo)
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},
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),
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// Fit is determined by inter-pod affinity.
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factory.RegisterFitPredicateFactory(
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"MatchInterPodAffinity",
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func(args factory.PluginFactoryArgs) algorithm.FitPredicate {
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return predicates.NewPodAffinityPredicate(args.NodeInfo, args.PodLister)
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},
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),
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// Fit is determined by non-conflicting disk volumes.
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factory.RegisterFitPredicate("NoDiskConflict", predicates.NoDiskConflict),
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// GeneralPredicates are the predicates that are enforced by all Kubernetes components
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// (e.g. kubelet and all schedulers)
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factory.RegisterFitPredicate("GeneralPredicates", predicates.GeneralPredicates),
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// Fit is determined based on whether a pod can tolerate all of the node's taints
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factory.RegisterFitPredicate("PodToleratesNodeTaints", predicates.PodToleratesNodeTaints),
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// Fit is determined by node memory pressure condition.
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factory.RegisterFitPredicate("CheckNodeMemoryPressure", predicates.CheckNodeMemoryPressurePredicate),
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// Fit is determined by node disk pressure condition.
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factory.RegisterFitPredicate("CheckNodeDiskPressure", predicates.CheckNodeDiskPressurePredicate),
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)
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}
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func defaultPriorities() sets.String {
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return sets.NewString(
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// spreads pods by minimizing the number of pods (belonging to the same service or replication controller) on the same node.
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factory.RegisterPriorityConfigFactory(
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"SelectorSpreadPriority",
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factory.PriorityConfigFactory{
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Function: func(args factory.PluginFactoryArgs) algorithm.PriorityFunction {
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return priorities.NewSelectorSpreadPriority(args.ServiceLister, args.ControllerLister, args.ReplicaSetLister)
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},
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Weight: 1,
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},
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),
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// pods should be placed in the same topological domain (e.g. same node, same rack, same zone, same power domain, etc.)
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// as some other pods, or, conversely, should not be placed in the same topological domain as some other pods.
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factory.RegisterPriorityConfigFactory(
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"InterPodAffinityPriority",
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factory.PriorityConfigFactory{
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Function: func(args factory.PluginFactoryArgs) algorithm.PriorityFunction {
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return priorities.NewInterPodAffinityPriority(args.NodeInfo, args.NodeLister, args.PodLister, args.HardPodAffinitySymmetricWeight)
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},
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Weight: 1,
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},
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),
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// Prioritize nodes by least requested utilization.
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factory.RegisterPriorityFunction2("LeastRequestedPriority", priorities.LeastRequestedPriorityMap, nil, 1),
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// Prioritizes nodes to help achieve balanced resource usage
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factory.RegisterPriorityFunction2("BalancedResourceAllocation", priorities.BalancedResourceAllocationMap, nil, 1),
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// Set this weight large enough to override all other priority functions.
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// TODO: Figure out a better way to do this, maybe at same time as fixing #24720.
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factory.RegisterPriorityFunction2("NodePreferAvoidPodsPriority", priorities.CalculateNodePreferAvoidPodsPriorityMap, nil, 10000),
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// Prioritizes nodes that have labels matching NodeAffinity
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factory.RegisterPriorityFunction2("NodeAffinityPriority", priorities.CalculateNodeAffinityPriorityMap, priorities.CalculateNodeAffinityPriorityReduce, 1),
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// TODO: explain what it does.
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factory.RegisterPriorityFunction2("TaintTolerationPriority", priorities.ComputeTaintTolerationPriorityMap, priorities.ComputeTaintTolerationPriorityReduce, 1),
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)
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}
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// getMaxVols checks the max PD volumes environment variable, otherwise returning a default value
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func getMaxVols(defaultVal int) int {
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if rawMaxVols := os.Getenv("KUBE_MAX_PD_VOLS"); rawMaxVols != "" {
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if parsedMaxVols, err := strconv.Atoi(rawMaxVols); err != nil {
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glog.Errorf("Unable to parse maxiumum PD volumes value, using default of %v: %v", defaultVal, err)
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} else if parsedMaxVols <= 0 {
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glog.Errorf("Maximum PD volumes must be a positive value, using default of %v", defaultVal)
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} else {
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return parsedMaxVols
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}
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}
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return defaultVal
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}
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func copyAndReplace(set sets.String, replaceWhat, replaceWith string) sets.String {
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result := sets.NewString(set.List()...)
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if result.Has(replaceWhat) {
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result.Delete(replaceWhat)
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result.Insert(replaceWith)
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}
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return result
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}
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// GetEquivalencePod returns a EquivalencePod which contains a group of pod attributes which can be reused.
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func GetEquivalencePod(pod *v1.Pod) interface{} {
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equivalencePod := EquivalencePod{}
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// For now we only consider pods:
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// 1. OwnerReferences is Controller
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// 2. OwnerReferences kind is in valid controller kinds
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// 3. with same OwnerReferences
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// to be equivalent
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if len(pod.OwnerReferences) != 0 {
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for _, ref := range pod.OwnerReferences {
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if *ref.Controller {
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equivalencePod.ControllerRef = ref
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// a pod can only belongs to one controller
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break
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}
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}
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}
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return &equivalencePod
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}
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// EquivalencePod is a group of pod attributes which can be reused as equivalence to schedule other pods.
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type EquivalencePod struct {
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ControllerRef metav1.OwnerReference
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}
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