Add a least-requested priority function

pkg/scheduler/generic_scheduler.go

@@ -63,18 +63,18 @@ func (g *genericScheduler) selectHost(priorityList HostPriorityList) (string, er
 	return hosts[ix], nil
 }
 
-func findNodesThatFit(pod api.Pod, podLister PodLister, predicates []FitPredicate, nodes []string) ([]string, error) {
-	filtered := []string{}
+func findNodesThatFit(pod api.Pod, podLister PodLister, predicates []FitPredicate, nodes api.MinionList) (api.MinionList, error) {
+	filtered := []api.Minion{}
 	machineToPods, err := MapPodsToMachines(podLister)
 	if err != nil {
-		return nil, err
+		return api.MinionList{}, err
 	}
-	for _, node := range nodes {
+	for _, node := range nodes.Items {
 		fits := true
 		for _, predicate := range predicates {
-			fit, err := predicate(pod, machineToPods[node], node)
+			fit, err := predicate(pod, machineToPods[node.ID], node.ID)
 			if err != nil {
-				return nil, err
+				return api.MinionList{}, err
 			}
 			if !fit {
 				fits = false
@@ -85,7 +85,7 @@ func findNodesThatFit(pod api.Pod, podLister PodLister, predicates []FitPredicat
 			filtered = append(filtered, node)
 		}
 	}
-	return filtered, nil
+	return api.MinionList{Items: filtered}, nil
 }
 
 func getMinHosts(list HostPriorityList) []string {
@@ -109,9 +109,9 @@ func EqualPriority(pod api.Pod, podLister PodLister, minionLister MinionLister)
 		fmt.Errorf("failed to list nodes: %v", err)
 		return []HostPriority{}, err
 	}
-	for _, minion := range nodes {
+	for _, minion := range nodes.Items {
 		result = append(result, HostPriority{
-			host:  minion,
+			host:  minion.ID,
 			score: 1,
 		})
 	}

pkg/scheduler/generic_scheduler_test.go

@@ -45,19 +45,29 @@ func numericPriority(pod api.Pod, podLister PodLister, minionLister MinionLister
 		fmt.Errorf("failed to list nodes: %v", err)
 		return nil, err
 	}
-	for _, minion := range nodes {
-		score, err := strconv.Atoi(minion)
+	for _, minion := range nodes.Items {
+		score, err := strconv.Atoi(minion.ID)
 		if err != nil {
 			return nil, err
 		}
 		result = append(result, HostPriority{
-			host:  minion,
+			host:  minion.ID,
 			score: score,
 		})
 	}
 	return result, nil
 }
 
+func makeMinionList(nodeNames []string) api.MinionList {
+	result := api.MinionList{
+		Items: make([]api.Minion, len(nodeNames)),
+	}
+	for ix := range nodeNames {
+		result.Items[ix].ID = nodeNames[ix]
+	}
+	return result
+}
+
 func TestGenericScheduler(t *testing.T) {
 	tests := []struct {
 		predicates   []FitPredicate
@@ -112,7 +122,7 @@ func TestGenericScheduler(t *testing.T) {
 	for _, test := range tests {
 		random := rand.New(rand.NewSource(0))
 		scheduler := NewGenericScheduler(test.predicates, test.prioritizer, FakePodLister([]api.Pod{}), random)
-		machine, err := scheduler.Schedule(test.pod, FakeMinionLister(test.nodes))
+		machine, err := scheduler.Schedule(test.pod, FakeMinionLister(makeMinionList(test.nodes)))
 		if test.expectsErr {
 			if err == nil {
 				t.Error("Unexpected non-error")

pkg/scheduler/listers.go

@@ -23,15 +23,15 @@ import (
 
 // MinionLister interface represents anything that can list minions for a scheduler.
 type MinionLister interface {
-	List() (machines []string, err error)
+	List() (list api.MinionList, err error)
 }
 
 // FakeMinionLister implements MinionLister on a []string for test purposes.
-type FakeMinionLister []string
+type FakeMinionLister api.MinionList
 
 // List returns minions as a []string.
-func (f FakeMinionLister) List() ([]string, error) {
-	return []string(f), nil
+func (f FakeMinionLister) List() (api.MinionList, error) {
+	return api.MinionList(f), nil
 }
 
 // PodLister interface represents anything that can list pods for a scheduler.

pkg/scheduler/priorities.go

@@ -0,0 +1,63 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package scheduler
+
+import (
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/resources"
+	"github.com/golang/glog"
+)
+
+// Calculate the occupancy on a node.  'node' has information about the resources on the node.
+// 'pods' is a list of pods currently scheduled on the node.
+func calculateOccupancy(node api.Minion, pods []api.Pod) HostPriority {
+	totalCPU := 0
+	totalMemory := 0
+	for ix := range pods {
+		for cIx := range pods[ix].DesiredState.Manifest.Containers {
+			container := &(pods[ix].DesiredState.Manifest.Containers[cIx])
+			totalCPU += container.CPU
+			totalMemory += container.Memory
+		}
+	}
+	percentageCPU := (totalCPU * 100) / resources.GetIntegerResource(node.NodeResources.Capacity, resources.CPU, 0)
+	percentageMemory := (totalMemory * 100) / resources.GetIntegerResource(node.NodeResources.Capacity, resources.Memory, 0)
+	glog.V(4).Infof("Least Requested Priority, AbsoluteRequested: (%d, %d) Percentage:(%d\\%m, %d\\%)", totalCPU, totalMemory, percentageCPU, percentageMemory)
+
+	return HostPriority{
+		host:  node.ID,
+		score: int((percentageCPU + percentageMemory) / 2),
+	}
+}
+
+// LeastRequestedPriority is a priority function that favors nodes with fewer requested resources.
+// It calculates the percentage of memory and CPU requested by pods scheduled on the node, and prioritizes
+// based on the minimum of the average of the fraction of requested to capacity.
+// Details: (Sum(requested cpu) / Capacity + Sum(requested memory) / Capacity) * 50
+func LeastRequestedPriority(pod api.Pod, podLister PodLister, minionLister MinionLister) (HostPriorityList, error) {
+	nodes, err := minionLister.List()
+	if err != nil {
+		return HostPriorityList{}, err
+	}
+	podsToMachines, err := MapPodsToMachines(podLister)
+
+	list := HostPriorityList{}
+	for _, node := range nodes.Items {
+		list = append(list, calculateOccupancy(node, podsToMachines[node.ID]))
+	}
+	return list, nil
+}

pkg/scheduler/priorities_test.go

@@ -0,0 +1,114 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package scheduler
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/resources"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+)
+
+func makeMinion(node string, cpu, memory int) api.Minion {
+	return api.Minion{
+		TypeMeta: api.TypeMeta{ID: node},
+		NodeResources: api.NodeResources{
+			Capacity: api.ResourceList{
+				resources.CPU:    util.NewIntOrStringFromInt(cpu),
+				resources.Memory: util.NewIntOrStringFromInt(memory),
+			},
+		},
+	}
+}
+
+func TestLeastRequested(t *testing.T) {
+	labels1 := map[string]string{
+		"foo": "bar",
+		"baz": "blah",
+	}
+	labels2 := map[string]string{
+		"bar": "foo",
+		"baz": "blah",
+	}
+	machine1State := api.PodState{
+		Host: "machine1",
+	}
+	machine2State := api.PodState{
+		Host: "machine2",
+	}
+	cpuOnly := api.PodState{
+		Manifest: api.ContainerManifest{
+			Containers: []api.Container{
+				{CPU: 1000},
+				{CPU: 2000},
+			},
+		},
+	}
+	cpuAndMemory := api.PodState{
+		Manifest: api.ContainerManifest{
+			Containers: []api.Container{
+				{CPU: 1000, Memory: 2000},
+				{CPU: 2000, Memory: 3000},
+			},
+		},
+	}
+	tests := []struct {
+		pod          api.Pod
+		pods         []api.Pod
+		nodes        []api.Minion
+		expectedList HostPriorityList
+		test         string
+	}{
+		{
+			nodes:        []api.Minion{makeMinion("machine1", 4000, 10000), makeMinion("machine2", 4000, 10000)},
+			expectedList: []HostPriority{{"machine1", 0}, {"machine2", 0}},
+			test:         "nothing scheduled",
+		},
+		{
+			nodes:        []api.Minion{makeMinion("machine1", 4000, 10000), makeMinion("machine2", 4000, 10000)},
+			expectedList: []HostPriority{{"machine1", 0}, {"machine2", 0}},
+			test:         "no resources requested",
+			pods: []api.Pod{
+				{CurrentState: machine1State, Labels: labels2},
+				{CurrentState: machine1State, Labels: labels1},
+				{CurrentState: machine2State, Labels: labels1},
+				{CurrentState: machine2State, Labels: labels1},
+			},
+		},
+		{
+			nodes:        []api.Minion{makeMinion("machine1", 4000, 10000), makeMinion("machine2", 4000, 10000)},
+			expectedList: []HostPriority{{"machine1", 37 /* int(75% / 2) */}, {"machine2", 62 /* int( 75% + 50% / 2) */}},
+			test:         "no resources requested",
+			pods: []api.Pod{
+				{DesiredState: cpuOnly, CurrentState: machine1State},
+				{DesiredState: cpuAndMemory, CurrentState: machine2State},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		list, err := LeastRequestedPriority(test.pod, FakePodLister(test.pods), FakeMinionLister(api.MinionList{Items: test.nodes}))
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+		if !reflect.DeepEqual(test.expectedList, list) {
+			t.Errorf("%s: expected %#v, got %#v", test.test, test.expectedList, list)
+		}
+	}
+}

pkg/scheduler/spreading.go

@@ -43,8 +43,8 @@ func CalculateSpreadPriority(pod api.Pod, podLister PodLister, minionLister Mini
 	}
 
 	result := []HostPriority{}
-	for _, minion := range minions {
-		result = append(result, HostPriority{host: minion, score: counts[minion]})
+	for _, minion := range minions.Items {
+		result = append(result, HostPriority{host: minion.ID, score: counts[minion.ID]})
 	}
 	return result, nil
 }

pkg/scheduler/spreading_test.go

@@ -100,7 +100,7 @@ func TestSpreadPriority(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		list, err := CalculateSpreadPriority(test.pod, FakePodLister(test.pods), FakeMinionLister(test.nodes))
+		list, err := CalculateSpreadPriority(test.pod, FakePodLister(test.pods), FakeMinionLister(makeMinionList(test.nodes)))
 		if err != nil {
 			t.Errorf("unexpected error: %v", err)
 		}

plugin/pkg/scheduler/factory/factory.go

@@ -202,9 +202,9 @@ type storeToMinionLister struct {
 	cache.Store
 }
 
-func (s *storeToMinionLister) List() (machines []string, err error) {
+func (s *storeToMinionLister) List() (machines api.MinionList, err error) {
 	for _, m := range s.Store.List() {
-		machines = append(machines, m.(*api.Minion).ID)
+		machines.Items = append(machines.Items, *(m.(*api.Minion)))
 	}
 	return machines, nil
 }

plugin/pkg/scheduler/factory/factory_test.go

@@ -223,10 +223,14 @@ func TestStoreToMinionLister(t *testing.T) {
 	}
 	sml := storeToMinionLister{store}
 
-	got, err := sml.List()
+	gotNodes, err := sml.List()
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
 	}
+	got := make([]string, len(gotNodes.Items))
+	for ix := range gotNodes.Items {
+		got[ix] = gotNodes.Items[ix].ID
+	}
 	if !ids.HasAll(got...) || len(got) != len(ids) {
 		t.Errorf("Expected %v, got %v", ids, got)
 	}

plugin/pkg/scheduler/scheduler_test.go

@@ -81,8 +81,10 @@ func TestScheduler(t *testing.T) {
 		var gotPod *api.Pod
 		var gotBinding *api.Binding
 		c := &Config{
-			MinionLister: scheduler.FakeMinionLister{"machine1"},
-			Algorithm:    item.algo,
+			MinionLister: scheduler.FakeMinionLister(
+				api.MinionList{Items: []api.Minion{{TypeMeta: api.TypeMeta{ID: "machine1"}}}},
+			),
+			Algorithm: item.algo,
 			Binder: fakeBinder{func(b *api.Binding) error {
 				gotBinding = b
 				return item.injectBindError