Kubelet: add usageNanoCores from CRI stats provider

kubernetes · Feb 7, 2019 · 01fbca2 · 01fbca2
1 parent 713eaf4
commit 01fbca2
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Showing 2 changed files with 170 additions and 0 deletions.
diff --git a/pkg/kubelet/stats/cri_stats_provider.go b/pkg/kubelet/stats/cri_stats_provider.go
@@ -22,6 +22,7 @@ import (
 	"path"
 	"sort"
 	"strings"
+	"sync"
 	"time"
 
 	cadvisorfs "github.com/google/cadvisor/fs"
@@ -38,6 +39,11 @@ import (
 	kubetypes "k8s.io/kubernetes/pkg/kubelet/types"
 )
 
+var (
+	// defaultCachePeriod is the default cache period for each cpuUsage.
+	defaultCachePeriod = 10 * time.Minute
+)
+
 // criStatsProvider implements the containerStatsProvider interface by getting
 // the container stats from CRI.
 type criStatsProvider struct {
@@ -54,6 +60,10 @@ type criStatsProvider struct {
 	imageService internalapi.ImageManagerService
 	// logMetrics provides the metrics for container logs
 	logMetricsService LogMetricsService
+
+	// cpuUsageCache caches the cpu usage for containers.
+	cpuUsageCache map[string]*runtimeapi.CpuUsage
+	mutex         sync.Mutex
 }
 
 // newCRIStatsProvider returns a containerStatsProvider implementation that
@@ -71,6 +81,7 @@ func newCRIStatsProvider(
 		runtimeService:    runtimeService,
 		imageService:      imageService,
 		logMetricsService: logMetricsService,
+		cpuUsageCache:     make(map[string]*runtimeapi.CpuUsage),
 	}
 }
 
@@ -165,6 +176,8 @@ func (p *criStatsProvider) ListPodStats() ([]statsapi.PodStats, error) {
 		}
 		ps.Containers = append(ps.Containers, *cs)
 	}
+	// cleanup outdated caches.
+	p.cleanupOutdatedCaches()
 
 	result := make([]statsapi.PodStats, 0, len(sandboxIDToPodStats))
 	for _, s := range sandboxIDToPodStats {
@@ -247,6 +260,8 @@ func (p *criStatsProvider) ListPodCPUAndMemoryStats() ([]statsapi.PodStats, erro
 		}
 		ps.Containers = append(ps.Containers, *cs)
 	}
+	// cleanup outdated caches.
+	p.cleanupOutdatedCaches()
 
 	result := make([]statsapi.PodStats, 0, len(sandboxIDToPodStats))
 	for _, s := range sandboxIDToPodStats {
@@ -450,6 +465,11 @@ func (p *criStatsProvider) makeContainerStats(
 		if stats.Cpu.UsageCoreNanoSeconds != nil {
 			result.CPU.UsageCoreNanoSeconds = &stats.Cpu.UsageCoreNanoSeconds.Value
 		}
+
+		usageNanoCores := p.getContainerUsageNanoCores(stats)
+		if usageNanoCores != nil {
+			result.CPU.UsageNanoCores = usageNanoCores
+		}
 	}
 	if stats.Memory != nil {
 		result.Memory.Time = metav1.NewTime(time.Unix(0, stats.Memory.Timestamp))
@@ -506,6 +526,11 @@ func (p *criStatsProvider) makeContainerCPUAndMemoryStats(
 		if stats.Cpu.UsageCoreNanoSeconds != nil {
 			result.CPU.UsageCoreNanoSeconds = &stats.Cpu.UsageCoreNanoSeconds.Value
 		}
+
+		usageNanoCores := p.getContainerUsageNanoCores(stats)
+		if usageNanoCores != nil {
+			result.CPU.UsageNanoCores = usageNanoCores
+		}
 	}
 	if stats.Memory != nil {
 		result.Memory.Time = metav1.NewTime(time.Unix(0, stats.Memory.Timestamp))
@@ -516,6 +541,44 @@ func (p *criStatsProvider) makeContainerCPUAndMemoryStats(
 	return result
 }
 
+// getContainerUsageNanoCores gets usageNanoCores based on cached usageCoreNanoSeconds.
+func (p *criStatsProvider) getContainerUsageNanoCores(stats *runtimeapi.ContainerStats) *uint64 {
+	if stats == nil || stats.Cpu == nil || stats.Cpu.UsageCoreNanoSeconds == nil {
+		return nil
+	}
+
+	p.mutex.Lock()
+	defer func() {
+		// Update cache with new value.
+		p.cpuUsageCache[stats.Attributes.Id] = stats.Cpu
+		p.mutex.Unlock()
+	}()
+
+	cached, ok := p.cpuUsageCache[stats.Attributes.Id]
+	if !ok || cached.UsageCoreNanoSeconds == nil {
+		return nil
+	}
+
+	nanoSeconds := stats.Cpu.Timestamp - cached.Timestamp
+	usageNanoCores := (stats.Cpu.UsageCoreNanoSeconds.Value - cached.UsageCoreNanoSeconds.Value) * uint64(time.Second/time.Nanosecond) / uint64(nanoSeconds)
+	return &usageNanoCores
+}
+
+func (p *criStatsProvider) cleanupOutdatedCaches() {
+	p.mutex.Lock()
+	defer p.mutex.Unlock()
+
+	for k, v := range p.cpuUsageCache {
+		if v == nil {
+			delete(p.cpuUsageCache, k)
+		}
+
+		if time.Since(time.Unix(0, v.Timestamp)) > defaultCachePeriod {
+			delete(p.cpuUsageCache, k)
+		}
+	}
+}
+
 // removeTerminatedContainer returns the specified container but with
 // the stats of the terminated containers removed.
 func removeTerminatedContainer(containers []*runtimeapi.Container) []*runtimeapi.Container {

diff --git a/pkg/kubelet/stats/cri_stats_provider_test.go b/pkg/kubelet/stats/cri_stats_provider_test.go
@@ -645,3 +645,110 @@ func makeFakeLogStats(seed int) *volume.Metrics {
 	m.InodesUsed = resource.NewQuantity(int64(seed+offsetInodeUsage), resource.BinarySI)
 	return m
 }
+
+func TestGetContainerUsageNanoCores(t *testing.T) {
+	var value0 uint64
+	var value1 uint64 = 10000000000
+
+	tests := []struct {
+		desc          string
+		cpuUsageCache map[string]*runtimeapi.CpuUsage
+		stats         *runtimeapi.ContainerStats
+		expected      *uint64
+	}{
+		{
+			desc:          "should return nil if stats is nil",
+			cpuUsageCache: map[string]*runtimeapi.CpuUsage{},
+		},
+		{
+			desc:          "should return nil if cpu stats is nil",
+			cpuUsageCache: map[string]*runtimeapi.CpuUsage{},
+			stats: &runtimeapi.ContainerStats{
+				Attributes: &runtimeapi.ContainerAttributes{
+					Id: "1",
+				},
+				Cpu: nil,
+			},
+		},
+		{
+			desc:          "should return nil if usageCoreNanoSeconds is nil",
+			cpuUsageCache: map[string]*runtimeapi.CpuUsage{},
+			stats: &runtimeapi.ContainerStats{
+				Attributes: &runtimeapi.ContainerAttributes{
+					Id: "1",
+				},
+				Cpu: &runtimeapi.CpuUsage{
+					Timestamp:            1,
+					UsageCoreNanoSeconds: nil,
+				},
+			},
+		},
+		{
+			desc:          "should return nil if cpu stats is not cached yet",
+			cpuUsageCache: map[string]*runtimeapi.CpuUsage{},
+			stats: &runtimeapi.ContainerStats{
+				Attributes: &runtimeapi.ContainerAttributes{
+					Id: "1",
+				},
+				Cpu: &runtimeapi.CpuUsage{
+					Timestamp: 1,
+					UsageCoreNanoSeconds: &runtimeapi.UInt64Value{
+						Value: 10000000000,
+					},
+				},
+			},
+		},
+		{
+			desc: "should return zero value if cached cpu stats is equal to current value",
+			stats: &runtimeapi.ContainerStats{
+				Attributes: &runtimeapi.ContainerAttributes{
+					Id: "1",
+				},
+				Cpu: &runtimeapi.CpuUsage{
+					Timestamp: 1,
+					UsageCoreNanoSeconds: &runtimeapi.UInt64Value{
+						Value: 10000000000,
+					},
+				},
+			},
+			cpuUsageCache: map[string]*runtimeapi.CpuUsage{
+				"1": {
+					Timestamp: 0,
+					UsageCoreNanoSeconds: &runtimeapi.UInt64Value{
+						Value: 10000000000,
+					},
+				},
+			},
+			expected: &value0,
+		},
+		{
+			desc: "should return correct value if cached cpu stats is not equal to current value",
+			stats: &runtimeapi.ContainerStats{
+				Attributes: &runtimeapi.ContainerAttributes{
+					Id: "1",
+				},
+				Cpu: &runtimeapi.CpuUsage{
+					Timestamp: int64(time.Second / time.Nanosecond),
+					UsageCoreNanoSeconds: &runtimeapi.UInt64Value{
+						Value: 20000000000,
+					},
+				},
+			},
+			cpuUsageCache: map[string]*runtimeapi.CpuUsage{
+				"1": {
+					Timestamp: 0,
+					UsageCoreNanoSeconds: &runtimeapi.UInt64Value{
+						Value: 10000000000,
+					},
+				},
+			},
+			expected: &value1,
+		},
+	}
+
+	for _, test := range tests {
+		provider := &criStatsProvider{cpuUsageCache: test.cpuUsageCache}
+		real := provider.getContainerUsageNanoCores(test.stats)
+		assert.Equal(t, test.expected, real, test.desc)
+	}
+}