Price-preferred node expander - part 1

cluster-autoscaler/expander/price/price.go

@@ -0,0 +1,84 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+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 price
+
+import (
+	"time"
+
+	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider"
+	"k8s.io/autoscaler/cluster-autoscaler/expander"
+	"k8s.io/kubernetes/plugin/pkg/scheduler/schedulercache"
+
+	"github.com/golang/glog"
+)
+
+// TODO: add preferred node
+type priceBased struct {
+	pricingModel cloudprovider.PricingModel
+}
+
+// NewStrategy returns an expansion strategy that picks nodes based on price and preferred node type.
+func NewStrategy(pricingModel cloudprovider.PricingModel) expander.Strategy {
+	return &priceBased{
+		pricingModel: pricingModel,
+	}
+}
+
+// BestOption selects option based on cost and preferred node type.
+func (p *priceBased) BestOption(expansionOptions []expander.Option, nodeInfos map[string]*schedulercache.NodeInfo) *expander.Option {
+	var bestOption *expander.Option
+	bestOptionScore := 0.0
+	now := time.Now()
+	then := now.Add(time.Hour)
+
+nextoption:
+	for i, option := range expansionOptions {
+		nodeInfo, found := nodeInfos[option.NodeGroup.Id()]
+		if !found {
+			glog.Warningf("No node info for %s", option.NodeGroup.Id())
+			continue
+		}
+		nodePrice, err := p.pricingModel.NodePrice(nodeInfo.Node(), now, then)
+		if err != nil {
+			glog.Warningf("Failed to calculate node price for %s: %v", option.NodeGroup.Id(), err)
+			continue
+		}
+		totalNodePrice := nodePrice * float64(option.NodeCount)
+		totalPodPrice := 0.0
+		for _, pod := range option.Pods {
+			podPrice, err := p.pricingModel.PodPrice(pod, now, then)
+			if err != nil {
+				glog.Warningf("Failed to calculate pod price for %s/%s: %v", pod.Namespace, pod.Name, err)
+				continue nextoption
+			}
+			totalPodPrice += podPrice
+		}
+		if totalPodPrice == 0 {
+			glog.Warningf("Total pod price is 0, skipping %s", option.NodeGroup.Id())
+			continue
+		}
+
+		optionScore := totalNodePrice / totalPodPrice
+		glog.V(5).Infof("Price of %s expansion is %f - ratio %f", option.NodeGroup.Id(), totalNodePrice)
+
+		if bestOption == nil || bestOptionScore > optionScore {
+			bestOption = &expansionOptions[i]
+			bestOptionScore = optionScore
+		}
+	}
+	return bestOption
+}

cluster-autoscaler/expander/price/price_test.go

@@ -0,0 +1,150 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+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 price
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"k8s.io/autoscaler/cluster-autoscaler/expander"
+
+	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/test"
+	. "k8s.io/autoscaler/cluster-autoscaler/utils/test"
+	apiv1 "k8s.io/kubernetes/pkg/api/v1"
+	"k8s.io/kubernetes/plugin/pkg/scheduler/schedulercache"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type testPricingModel struct {
+	nodePrice map[string]float64
+	podPrice  map[string]float64
+}
+
+func (tpm *testPricingModel) NodePrice(node *apiv1.Node, startTime time.Time, endTime time.Time) (float64, error) {
+	if price, found := tpm.nodePrice[node.Name]; found {
+		return price, nil
+	}
+	return 0.0, fmt.Errorf("price for node %v not found", node.Name)
+}
+
+func (tpm *testPricingModel) PodPrice(node *apiv1.Pod, startTime time.Time, endTime time.Time) (float64, error) {
+	if price, found := tpm.podPrice[node.Name]; found {
+		return price, nil
+	}
+	return 0.0, fmt.Errorf("price for pod %v not found", node.Name)
+}
+
+func TestPriceExpander(t *testing.T) {
+	n1 := BuildTestNode("n1", 1000, 1000)
+	n2 := BuildTestNode("n2", 10000, 1000)
+
+	p1 := BuildTestPod("p1", 1000, 0)
+	p2 := BuildTestPod("p2", 500, 0)
+
+	provider := testprovider.NewTestCloudProvider(nil, nil)
+	provider.AddNodeGroup("ng1", 1, 10, 1)
+	provider.AddNodeGroup("ng2", 1, 10, 1)
+	provider.AddNode("ng1", n1)
+	provider.AddNode("ng2", n2)
+	ng1, _ := provider.NodeGroupForNode(n1)
+	ng2, _ := provider.NodeGroupForNode(n2)
+
+	ni1 := schedulercache.NewNodeInfo()
+	ni1.SetNode(n1)
+	ni2 := schedulercache.NewNodeInfo()
+	ni2.SetNode(n2)
+	nodeInfosForGroups := map[string]*schedulercache.NodeInfo{
+		"ng1": ni1, "ng2": ni2,
+	}
+
+	// All node groups accept the same set of pods
+	options := []expander.Option{
+		{
+			NodeGroup: ng1,
+			NodeCount: 2,
+			Pods:      []*apiv1.Pod{p1, p2},
+			Debug:     "1",
+		},
+		{
+			NodeGroup: ng2,
+			NodeCount: 1,
+			Pods:      []*apiv1.Pod{p1, p2},
+			Debug:     "2",
+		},
+	}
+
+	// First node group is cheapter
+	assert.Equal(t, "1", NewStrategy(&testPricingModel{
+		podPrice: map[string]float64{
+			"p1": 20.0,
+			"p2": 10.0,
+		},
+		nodePrice: map[string]float64{
+			"n1": 20.0,
+			"n2": 200.0,
+		},
+	}).BestOption(options, nodeInfosForGroups).Debug)
+
+	// Second node group is cheapter
+	assert.Equal(t, "2", NewStrategy(&testPricingModel{
+		podPrice: map[string]float64{
+			"p1": 20.0,
+			"p2": 10.0,
+		},
+		nodePrice: map[string]float64{
+			"n1": 200.0,
+			"n2": 100.0,
+		},
+	}).BestOption(options, nodeInfosForGroups).Debug)
+
+	// First group accept 1 pod and second accepts 2.
+	options2 := []expander.Option{
+		{
+			NodeGroup: ng1,
+			NodeCount: 2,
+			Pods:      []*apiv1.Pod{p1},
+			Debug:     "1",
+		},
+		{
+			NodeGroup: ng2,
+			NodeCount: 1,
+			Pods:      []*apiv1.Pod{p1, p2},
+			Debug:     "2",
+		},
+	}
+
+	// Both node groups are equally expensive. However 2
+	// accept two pods.
+	assert.Equal(t, "2", NewStrategy(&testPricingModel{
+		podPrice: map[string]float64{
+			"p1": 20.0,
+			"p2": 10.0,
+		},
+		nodePrice: map[string]float64{
+			"n1": 200.0,
+			"n2": 200.0,
+		},
+	}).BestOption(options2, nodeInfosForGroups).Debug)
+
+	// Errors are expected
+	assert.Nil(t, NewStrategy(&testPricingModel{
+		podPrice:  map[string]float64{},
+		nodePrice: map[string]float64{},
+	}).BestOption(options2, nodeInfosForGroups))
+}