import (
"bufio"
"bytes"
- "flag"
"errors"
+ "flag"
"fmt"
"io"
"io/ioutil"
"os"
"os/exec"
"os/signal"
+ "strconv"
"strings"
"syscall"
"time"
#include <stdlib.h>
*/
import "C"
+
// The above block of magic allows us to look up user_hz via _SC_CLK_TCK.
type Cgroup struct {
cid string
}
-func CopyPipeToChan(in io.Reader, out chan string, done chan<- bool) {
- s := bufio.NewScanner(in)
- for s.Scan() {
- out <- s.Text()
- }
- done <- true
-}
+var childLog = log.New(os.Stderr, "", 0)
+var statLog = log.New(os.Stderr, "crunchstat: ", 0)
-func CopyChanToPipe(in <-chan string, out io.Writer) {
- for s := range in {
- fmt.Fprintln(out, s)
+const (
+ MaxLogLine = 1 << 14 // Child stderr lines >16KiB will be split
+)
+
+func CopyPipeToChildLog(in io.ReadCloser, done chan<- bool) {
+ reader := bufio.NewReaderSize(in, MaxLogLine)
+ var prefix string
+ for {
+ line, isPrefix, err := reader.ReadLine()
+ if err == io.EOF {
+ break
+ } else if err != nil {
+ statLog.Fatal("error reading child stderr:", err)
+ }
+ var suffix string
+ if isPrefix {
+ suffix = "[...]"
+ }
+ childLog.Print(prefix, string(line), suffix)
+ // Set up prefix for following line
+ if isPrefix {
+ prefix = "[...]"
+ } else {
+ prefix = ""
+ }
}
+ done <- true
+ in.Close()
}
-func OpenAndReadAll(filename string, log_chan chan<- string) ([]byte, error) {
- in, err := os.Open(filename)
+func ReadAllOrWarn(in *os.File) ([]byte, error) {
+ content, err := ioutil.ReadAll(in)
if err != nil {
- if log_chan != nil {
- log_chan <- fmt.Sprintf("crunchstat: open %s: %s", filename, err)
- }
- return nil, err
- }
- defer in.Close()
- {
- content, err := ioutil.ReadAll(in)
- if err != nil && log_chan != nil {
- log_chan <- fmt.Sprintf("crunchstat: read %s: %s", filename, err)
- }
- return content, err
+ statLog.Printf("error reading %s: %s\n", in.Name(), err)
}
+ return content, err
}
-var reportedStatFile map[string]bool
-var reportedNoStatFile map[string]bool
+var reportedStatFile = map[string]string{}
-// Find the cgroup stats file in /sys/fs corresponding to the target
-// cgroup.
+// Open the cgroup stats file in /sys/fs corresponding to the target
+// cgroup, and return an *os.File. If no stats file is available,
+// return nil.
//
// TODO: Instead of trying all options, choose a process in the
// container, and read /proc/PID/cgroup to determine the appropriate
// cgroup root for the given statgroup. (This will avoid falling back
// to host-level stats during container setup and teardown.)
-func FindStat(stderr chan<- string, cgroup Cgroup, statgroup string, stat string) string {
- if reportedStatFile == nil {
- reportedStatFile = make(map[string]bool)
- reportedNoStatFile = make(map[string]bool)
+func OpenStatFile(cgroup Cgroup, statgroup string, stat string) (*os.File, error) {
+ var paths []string
+ if cgroup.cid != "" {
+ // Collect container's stats
+ paths = []string{
+ fmt.Sprintf("%s/%s/%s/%s/%s", cgroup.root, statgroup, cgroup.parent, cgroup.cid, stat),
+ fmt.Sprintf("%s/%s/%s/%s", cgroup.root, cgroup.parent, cgroup.cid, stat),
+ }
+ } else {
+ // Collect this host's stats
+ paths = []string{
+ fmt.Sprintf("%s/%s/%s", cgroup.root, statgroup, stat),
+ fmt.Sprintf("%s/%s", cgroup.root, stat),
+ }
}
-
var path string
- path = fmt.Sprintf("%s/%s/%s/%s/%s", cgroup.root, statgroup, cgroup.parent, cgroup.cid, stat)
- if _, err := os.Stat(path); err != nil {
- path = fmt.Sprintf("%s/%s/%s/%s", cgroup.root, cgroup.parent, cgroup.cid, stat)
- }
- if _, err := os.Stat(path); err != nil {
- path = fmt.Sprintf("%s/%s/%s", cgroup.root, statgroup, stat)
- }
- if _, err := os.Stat(path); err != nil {
- path = fmt.Sprintf("%s/%s", cgroup.root, stat)
- }
- if _, err := os.Stat(path); err != nil {
- if _, ok := reportedNoStatFile[stat]; !ok {
- stderr <- fmt.Sprintf("crunchstat: did not find stats file (root %s, parent %s, cid %s, statgroup %s, stat %s)", cgroup.root, cgroup.parent, cgroup.cid, statgroup, stat)
- reportedNoStatFile[stat] = true
+ var file *os.File
+ var err error
+ for _, path = range paths {
+ file, err = os.Open(path)
+ if err == nil {
+ break
+ } else {
+ path = ""
}
- return ""
}
- if _, ok := reportedStatFile[path]; !ok {
- stderr <- fmt.Sprintf("crunchstat: reading stats from %s", path)
- reportedStatFile[path] = true
+ if pathWas, ok := reportedStatFile[stat]; !ok || pathWas != path {
+ // Log whenever we start using a new/different cgroup
+ // stat file for a given statistic. This typically
+ // happens 1 to 3 times per statistic, depending on
+ // whether we happen to collect stats [a] before any
+ // processes have been created in the container and
+ // [b] after all contained processes have exited.
+ if path == "" {
+ statLog.Printf("notice: stats not available: stat %s, statgroup %s, cid %s, parent %s, root %s\n", stat, statgroup, cgroup.cid, cgroup.parent, cgroup.root)
+ } else if ok {
+ statLog.Printf("notice: stats moved from %s to %s\n", reportedStatFile[stat], path)
+ } else {
+ statLog.Printf("notice: reading stats from %s\n", path)
+ }
+ reportedStatFile[stat] = path
}
- return path
+ return file, err
}
-func GetContainerNetStats(stderr chan<- string, cgroup Cgroup) (io.Reader, error) {
- procsFilename := FindStat(stderr, cgroup, "cpuacct", "cgroup.procs")
- procsFile, err := os.Open(procsFilename)
+func GetContainerNetStats(cgroup Cgroup) (io.Reader, error) {
+ procsFile, err := OpenStatFile(cgroup, "cpuacct", "cgroup.procs")
if err != nil {
- stderr <- fmt.Sprintf("crunchstat: open %s: %s", procsFilename, err)
return nil, err
}
defer procsFile.Close()
for reader.Scan() {
taskPid := reader.Text()
statsFilename := fmt.Sprintf("/proc/%s/net/dev", taskPid)
- stats, err := OpenAndReadAll(statsFilename, stderr)
+ stats, err := ioutil.ReadFile(statsFilename)
if err != nil {
+ statLog.Printf("error reading %s: %s\n", statsFilename, err)
continue
}
return strings.NewReader(string(stats)), nil
rxBytes int64
}
-func DoBlkIoStats(stderr chan<- string, cgroup Cgroup, lastSample map[string]IoSample) (map[string]IoSample) {
- blkio_io_service_bytes := FindStat(stderr, cgroup, "blkio", "blkio.io_service_bytes")
- if blkio_io_service_bytes == "" {
- return lastSample
- }
-
- c, err := os.Open(blkio_io_service_bytes)
+func DoBlkIoStats(cgroup Cgroup, lastSample map[string]IoSample) {
+ c, err := OpenStatFile(cgroup, "blkio", "blkio.io_service_bytes")
if err != nil {
- stderr <- fmt.Sprintf("crunchstat: open %s: %s", blkio_io_service_bytes, err)
- return lastSample
+ return
}
defer c.Close()
b := bufio.NewScanner(c)
}
newSamples[device] = thisSample
}
- if lastSample == nil {
- lastSample = make(map[string]IoSample)
- }
for dev, sample := range newSamples {
if sample.txBytes < 0 || sample.rxBytes < 0 {
continue
if prev, ok := lastSample[dev]; ok {
delta = fmt.Sprintf(" -- interval %.4f seconds %d write %d read",
sample.sampleTime.Sub(prev.sampleTime).Seconds(),
- sample.txBytes - prev.txBytes,
- sample.rxBytes - prev.rxBytes)
+ sample.txBytes-prev.txBytes,
+ sample.rxBytes-prev.rxBytes)
}
- stderr <- fmt.Sprintf("crunchstat: blkio:%s %d write %d read%s", dev, sample.txBytes, sample.rxBytes, delta)
+ statLog.Printf("blkio:%s %d write %d read%s\n", dev, sample.txBytes, sample.rxBytes, delta)
lastSample[dev] = sample
}
- return lastSample
}
type MemSample struct {
memStat map[string]int64
}
-func DoMemoryStats(stderr chan<- string, cgroup Cgroup) {
- memory_stat := FindStat(stderr, cgroup, "memory", "memory.stat")
- if memory_stat == "" {
- return
- }
- c, err := os.Open(memory_stat)
+func DoMemoryStats(cgroup Cgroup) {
+ c, err := OpenStatFile(cgroup, "memory", "memory.stat")
if err != nil {
- stderr <- fmt.Sprintf("crunchstat: open %s: %s", memory_stat, err)
return
}
defer c.Close()
b := bufio.NewScanner(c)
thisSample := MemSample{time.Now(), make(map[string]int64)}
- wantStats := [...]string{"cache", "pgmajfault", "rss"}
+ wantStats := [...]string{"cache", "swap", "pgmajfault", "rss"}
for b.Scan() {
var stat string
var val int64
outstat.WriteString(fmt.Sprintf(" %d %s", val, key))
}
}
- stderr <- fmt.Sprintf("crunchstat: mem%s", outstat.String())
+ statLog.Printf("mem%s\n", outstat.String())
}
-func DoNetworkStats(stderr chan<- string, cgroup Cgroup, lastSample map[string]IoSample) (map[string]IoSample) {
+func DoNetworkStats(cgroup Cgroup, lastSample map[string]IoSample) {
sampleTime := time.Now()
- stats, err := GetContainerNetStats(stderr, cgroup)
- if err != nil { return lastSample }
-
- if lastSample == nil {
- lastSample = make(map[string]IoSample)
+ stats, err := GetContainerNetStats(cgroup)
+ if err != nil {
+ return
}
+
scanner := bufio.NewScanner(stats)
- Iface: for scanner.Scan() {
+ for scanner.Scan() {
var ifName string
var rx, tx int64
- words := bufio.NewScanner(strings.NewReader(scanner.Text()))
- words.Split(bufio.ScanWords)
- wordIndex := 0
- for words.Scan() {
- word := words.Text()
- switch wordIndex {
- case 0:
- ifName = strings.TrimRight(word, ":")
- case 1:
- if _, err := fmt.Sscanf(word, "%d", &rx); err != nil {
- continue Iface
- }
- case 9:
- if _, err := fmt.Sscanf(word, "%d", &tx); err != nil {
- continue Iface
- }
- }
- wordIndex++
+ words := strings.Fields(scanner.Text())
+ if len(words) != 17 {
+ // Skip lines with wrong format
+ continue
}
- if ifName == "lo" || ifName == "" || wordIndex != 17 {
+ ifName = strings.TrimRight(words[0], ":")
+ if ifName == "lo" || ifName == "" {
// Skip loopback interface and lines with wrong format
continue
}
+ if tx, err = strconv.ParseInt(words[9], 10, 64); err != nil {
+ continue
+ }
+ if rx, err = strconv.ParseInt(words[1], 10, 64); err != nil {
+ continue
+ }
nextSample := IoSample{}
nextSample.sampleTime = sampleTime
nextSample.txBytes = tx
nextSample.rxBytes = rx
var delta string
- if lastSample, ok := lastSample[ifName]; ok {
- interval := nextSample.sampleTime.Sub(lastSample.sampleTime).Seconds()
+ if prev, ok := lastSample[ifName]; ok {
+ interval := nextSample.sampleTime.Sub(prev.sampleTime).Seconds()
delta = fmt.Sprintf(" -- interval %.4f seconds %d tx %d rx",
interval,
- tx - lastSample.txBytes,
- rx - lastSample.rxBytes)
+ tx-prev.txBytes,
+ rx-prev.rxBytes)
}
- stderr <- fmt.Sprintf("crunchstat: net:%s %d tx %d rx%s",
- ifName, tx, rx, delta)
+ statLog.Printf("net:%s %d tx %d rx%s\n", ifName, tx, rx, delta)
lastSample[ifName] = nextSample
}
- return lastSample
}
type CpuSample struct {
+ hasData bool // to distinguish the zero value from real data
sampleTime time.Time
user float64
sys float64
// Return the number of CPUs available in the container. Return 0 if
// we can't figure out the real number of CPUs.
-func GetCpuCount(stderr chan<- string, cgroup Cgroup) (int64) {
- cpuset_cpus := FindStat(stderr, cgroup, "cpuset", "cpuset.cpus")
- if cpuset_cpus == "" {
- return 0
- }
- b, err := OpenAndReadAll(cpuset_cpus, stderr)
+func GetCpuCount(cgroup Cgroup) int64 {
+ cpusetFile, err := OpenStatFile(cgroup, "cpuset", "cpuset.cpus")
if err != nil {
return 0
}
+ defer cpusetFile.Close()
+ b, err := ReadAllOrWarn(cpusetFile)
sp := strings.Split(string(b), ",")
cpus := int64(0)
for _, v := range sp {
return cpus
}
-func DoCpuStats(stderr chan<- string, cgroup Cgroup, lastSample *CpuSample) (*CpuSample) {
- cpuacct_stat := FindStat(stderr, cgroup, "cpuacct", "cpuacct.stat")
- if cpuacct_stat == "" {
- return lastSample
+func DoCpuStats(cgroup Cgroup, lastSample *CpuSample) {
+ statFile, err := OpenStatFile(cgroup, "cpuacct", "cpuacct.stat")
+ if err != nil {
+ return
}
- b, err := OpenAndReadAll(cpuacct_stat, stderr)
+ defer statFile.Close()
+ b, err := ReadAllOrWarn(statFile)
if err != nil {
- return lastSample
+ return
}
- nextSample := &CpuSample{time.Now(), 0, 0, GetCpuCount(stderr, cgroup)}
+ nextSample := CpuSample{true, time.Now(), 0, 0, GetCpuCount(cgroup)}
var userTicks, sysTicks int64
fmt.Sscanf(string(b), "user %d\nsystem %d", &userTicks, &sysTicks)
user_hz := float64(C.sysconf(C._SC_CLK_TCK))
nextSample.sys = float64(sysTicks) / user_hz
delta := ""
- if lastSample != nil {
+ if lastSample.hasData {
delta = fmt.Sprintf(" -- interval %.4f seconds %.4f user %.4f sys",
nextSample.sampleTime.Sub(lastSample.sampleTime).Seconds(),
- nextSample.user - lastSample.user,
- nextSample.sys - lastSample.sys)
+ nextSample.user-lastSample.user,
+ nextSample.sys-lastSample.sys)
}
- stderr <- fmt.Sprintf("crunchstat: cpu %.4f user %.4f sys %d cpus%s",
+ statLog.Printf("cpu %.4f user %.4f sys %d cpus%s\n",
nextSample.user, nextSample.sys, nextSample.cpus, delta)
- return nextSample
+ *lastSample = nextSample
}
-func PollCgroupStats(cgroup Cgroup, stderr chan string, poll int64, stop_poll_chan <-chan bool) {
- var lastNetSample map[string]IoSample = nil
- var lastDiskSample map[string]IoSample = nil
- var lastCpuSample *CpuSample = nil
+func PollCgroupStats(cgroup Cgroup, poll int64, stop_poll_chan <-chan bool) {
+ var lastNetSample = map[string]IoSample{}
+ var lastDiskSample = map[string]IoSample{}
+ var lastCpuSample = CpuSample{}
poll_chan := make(chan bool, 1)
go func() {
case <-poll_chan:
// Emit stats, then select again.
}
- DoMemoryStats(stderr, cgroup)
- lastCpuSample = DoCpuStats(stderr, cgroup, lastCpuSample)
- lastDiskSample = DoBlkIoStats(stderr, cgroup, lastDiskSample)
- lastNetSample = DoNetworkStats(stderr, cgroup, lastNetSample)
+ DoMemoryStats(cgroup)
+ DoCpuStats(cgroup, &lastCpuSample)
+ DoBlkIoStats(cgroup, lastDiskSample)
+ DoNetworkStats(cgroup, lastNetSample)
}
}
flag.Parse()
if cgroup_root == "" {
- logger.Fatal("Must provide -cgroup-root")
+ statLog.Fatal("error: must provide -cgroup-root")
}
- stderr_chan := make(chan string, 1)
- defer close(stderr_chan)
finish_chan := make(chan bool)
defer close(finish_chan)
- go CopyChanToPipe(stderr_chan, os.Stderr)
-
var cmd *exec.Cmd
if len(flag.Args()) > 0 {
// Set up subprocess
cmd = exec.Command(flag.Args()[0], flag.Args()[1:]...)
- logger.Print("Running ", flag.Args())
+ childLog.Println("Running", flag.Args())
// Child process will use our stdin and stdout pipes
// (we close our copies below)
cmd.Stdout = os.Stdout
// Forward SIGINT and SIGTERM to inner process
- term := make(chan os.Signal, 1)
+ sigChan := make(chan os.Signal, 1)
go func(sig <-chan os.Signal) {
catch := <-sig
if cmd.Process != nil {
cmd.Process.Signal(catch)
}
- logger.Print("caught signal: ", catch)
- }(term)
- signal.Notify(term, syscall.SIGTERM)
- signal.Notify(term, syscall.SIGINT)
+ statLog.Println("notice: caught signal:", catch)
+ }(sigChan)
+ signal.Notify(sigChan, syscall.SIGTERM)
+ signal.Notify(sigChan, syscall.SIGINT)
// Funnel stderr through our channel
stderr_pipe, err := cmd.StderrPipe()
if err != nil {
- logger.Fatal(err)
+ statLog.Fatalln("error in StderrPipe:", err)
}
- go CopyPipeToChan(stderr_pipe, stderr_chan, finish_chan)
+ go CopyPipeToChildLog(stderr_pipe, finish_chan)
// Run subprocess
if err := cmd.Start(); err != nil {
- logger.Fatal(err)
+ statLog.Fatalln("error in cmd.Start:", err)
}
// Close stdin/stdout in this (parent) process
ok := false
var i time.Duration
for i = 0; i < time.Duration(wait)*time.Second; i += (100 * time.Millisecond) {
- cid, err := OpenAndReadAll(cgroup_cidfile, nil)
+ cid, err := ioutil.ReadFile(cgroup_cidfile)
if err == nil && len(cid) > 0 {
ok = true
container_id = string(cid)
time.Sleep(100 * time.Millisecond)
}
if !ok {
- logger.Printf("Could not read cid file %s", cgroup_cidfile)
+ statLog.Println("error reading cid file:", cgroup_cidfile)
}
}
stop_poll_chan := make(chan bool, 1)
cgroup := Cgroup{cgroup_root, cgroup_parent, container_id}
- go PollCgroupStats(cgroup, stderr_chan, poll, stop_poll_chan)
+ go PollCgroupStats(cgroup, poll, stop_poll_chan)
// When the child exits, tell the polling goroutine to stop.
defer func() { stop_poll_chan <- true }()
os.Exit(status.ExitStatus())
}
} else {
- logger.Fatalf("cmd.Wait: %v", err)
+ statLog.Fatalln("error in cmd.Wait:", err)
}
}
}
projects / arvados.git / blobdiff