stats writers

cadvisor.go

@@ -44,7 +44,9 @@ func main() {
 		NumSamples:  *argSampleSize,
 		ResetPeriod: *argResetPeriod,
 	})
-	containerManager, err := manager.New()
+
+	// TODO(monnand): Add stats writer for manager
+	containerManager, err := manager.New(nil)
 	if err != nil {
 		log.Fatalf("Failed to create a Container Manager: %s", err)
 	}

manager/container.go

@@ -43,9 +43,10 @@ type containerInfo struct {
 }
 
 type containerData struct {
-	handler container.ContainerHandler
-	info    containerInfo
-	lock    sync.Mutex
+	handler   container.ContainerHandler
+	info      containerInfo
+	statsChan chan<- *ContainerStats
+	lock      sync.Mutex
 
 	// Tells the container to stop.
 	stop chan bool
@@ -84,7 +85,7 @@ func (c *containerData) GetInfo() (*containerInfo, error) {
 	return &ret, nil
 }
 
-func NewContainerData(containerName string) (*containerData, error) {
+func NewContainerData(containerName string, statsChan chan<- *ContainerStats) (*containerData, error) {
 	cont := &containerData{}
 	handler, err := container.NewContainerHandler(containerName)
 	if err != nil {
@@ -98,6 +99,7 @@ func NewContainerData(containerName string) (*containerData, error) {
 	cont.info.Name = ref.Name
 	cont.info.Aliases = ref.Aliases
 	cont.info.Stats = list.New()
+	cont.statsChan = statsChan
 	cont.stop = make(chan bool, 1)
 
 	return cont, nil
@@ -151,6 +153,15 @@ func (c *containerData) updateStats() error {
 	if stats == nil {
 		return nil
 	}
+	if c.statsChan != nil {
+		ref, err := c.handler.ContainerReference()
+		if err == nil {
+			c.statsChan <- &ContainerStats{
+				ContainerReference: ref,
+				Stats:              stats,
+			}
+		}
+	}
 	summary, err := c.handler.StatsSummary()
 	if err != nil {
 		return err

manager/manager.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/google/cadvisor/container"
 	"github.com/google/cadvisor/info"
+	"github.com/google/cadvisor/storage"
 )
 
 type Manager interface {
@@ -38,7 +39,7 @@ type Manager interface {
 	GetVersionInfo() (*info.VersionInfo, error)
 }
 
-func New() (Manager, error) {
+func New(statsWriter storage.ContainerStatsWriter) (Manager, error) {
 	newManager := &manager{}
 	newManager.containers = make(map[string]*containerData)
 
@@ -55,6 +56,15 @@ func New() (Manager, error) {
 	}
 	newManager.versionInfo = *versionInfo
 	log.Printf("Version: %+v", newManager.versionInfo)
+	if statsWriter != nil {
+		// XXX(monnand): about numWorkers and queueLength, should we make it
+		// configurable?
+		ch, err := StartContainerStatsWriters(16, 64, statsWriter)
+		if err != nil {
+			return nil, err
+		}
+		newManager.statsChan = ch
+	}
 
 	return newManager, nil
 }
@@ -62,6 +72,7 @@ func New() (Manager, error) {
 type manager struct {
 	containers     map[string]*containerData
 	containersLock sync.RWMutex
+	statsChan      chan<- *ContainerStats
 	machineInfo    info.MachineInfo
 	versionInfo    info.VersionInfo
 }
@@ -160,7 +171,7 @@ func (m *manager) GetVersionInfo() (*info.VersionInfo, error) {
 
 // Create a container. This expects to only be called from the global manager thread.
 func (m *manager) createContainer(containerName string) (*containerData, error) {
-	cont, err := NewContainerData(containerName)
+	cont, err := NewContainerData(containerName, m.statsChan)
 	if err != nil {
 		return nil, err
 	}

manager/statsproc.go

@@ -15,6 +15,7 @@
 package manager
 
 import (
+	"fmt"
 	"log"
 
 	"github.com/google/cadvisor/info"
@@ -24,31 +25,35 @@ import (
 type ContainerStats struct {
 	ContainerReference info.ContainerReference
 	Stats              *info.ContainerStats
-	ResChan            chan<- error
+
+	// ResChan is nil if the sender wants to ignore the result
+	ResChan chan<- error
 }
 
-type ContainerStatsProcessor interface {
-	StartStatsProcessors(numProcs int) (chan<- *ContainerStats, error)
-	StopAllProcessors()
-}
-
-type containerStatsWriter struct {
-	config *storage.Config
-}
-
-func (self *containerStatsWriter) StartStatsProcessors(numProcs int) (chan<- *ContainerStats, error) {
-	ch := make(chan *ContainerStats)
-	statsWriter, err := storage.NewContainerStatsWriter(self.config)
-	if err != nil {
-		return nil, err
+// Create numWorkers goroutines to write container stats info into the
+// specified storage.  Returns a write-only channel for the caller to write
+// container stats. Closing this channel will stop all workers.
+func StartContainerStatsWriters(
+	numWorkers int,
+	queueLength int,
+	statsWriter storage.ContainerStatsWriter,
+) (chan<- *ContainerStats, error) {
+	if statsWriter == nil {
+		return nil, fmt.Errorf("invalid stats writer")
 	}
-	for i := 0; i < numProcs; i++ {
-		go self.process(statsWriter, ch)
+	var ch chan *ContainerStats
+	if queueLength > 0 {
+		ch = make(chan *ContainerStats, queueLength)
+	} else {
+		ch = make(chan *ContainerStats)
+	}
+	for i := 0; i < numWorkers; i++ {
+		go writeContainerStats(statsWriter, ch)
 	}
 	return ch, nil
 }
 
-func (self *containerStatsWriter) process(statsWriter storage.ContainerStatsWriter, ch <-chan *ContainerStats) {
+func writeContainerStats(statsWriter storage.ContainerStatsWriter, ch <-chan *ContainerStats) {
 	for stats := range ch {
 		err := statsWriter.Write(stats.ContainerReference, stats.Stats)
 		if err != nil {