+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
+// Package crunchstat reports resource usage (CPU, memory, disk,
+// network) for a cgroup.
package crunchstat
import (
"fmt"
"io"
"io/ioutil"
- "log"
"os"
+ "regexp"
+ "sort"
"strconv"
"strings"
+ "sync"
+ "syscall"
"time"
)
-// This magically allows us to look up user_hz via _SC_CLK_TCK:
-
-/*
-#include <unistd.h>
-#include <sys/types.h>
-#include <pwd.h>
-#include <stdlib.h>
-*/
-import "C"
-
// A Reporter gathers statistics for a cgroup and writes them to a
// log.Logger.
type Reporter struct {
// CID of the container to monitor. If empty, read the CID
- // from CIDFile.
+ // from CIDFile (first waiting until a non-empty file appears
+ // at CIDFile). If CIDFile is also empty, report host
+ // statistics.
CID string
- // Where cgroup special files live on this system
- CgroupRoot string
- CgroupParent string
- // Path to a file we can read CID from. If CIDFile is empty or
- // nonexistent, wait for it to appear.
+
+ // Path to a file we can read CID from.
CIDFile string
- // Interval between samples
- Poll time.Duration
+ // Where cgroup accounting files live on this system, e.g.,
+ // "/sys/fs/cgroup".
+ CgroupRoot string
+
+ // Parent cgroup, e.g., "docker".
+ CgroupParent string
+
+ // Interval between samples. Must be positive.
+ PollPeriod time.Duration
+
+ // Temporary directory, will be monitored for available, used & total space.
+ TempDir string
+
+ // Where to write statistics. Must not be nil.
+ Logger interface {
+ Printf(fmt string, args ...interface{})
+ }
- // Where to write statistics.
- Logger *log.Logger
+ kernelPageSize int64
+ reportedStatFile map[string]string
+ lastNetSample map[string]ioSample
+ lastDiskIOSample map[string]ioSample
+ lastCPUSample cpuSample
+ lastDiskSpaceSample diskSpaceSample
- reportedStatFile map[string]string
- lastNetSample map[string]IoSample
- lastDiskSample map[string]IoSample
- lastCPUSample CpuSample
+ reportPIDs map[string]int
+ reportPIDsMu sync.Mutex
- done chan struct{}
+ done chan struct{} // closed when we should stop reporting
+ flushed chan struct{} // closed when we have made our last report
}
-// Wait (if necessary) for the CID to appear in CIDFile, then start
-// reporting statistics.
+// Start starts monitoring in a new goroutine, and returns
+// immediately.
//
-// Start should not be called more than once on a Reporter.
+// The monitoring goroutine waits for a non-empty CIDFile to appear
+// (unless CID is non-empty). Then it waits for the accounting files
+// to appear for the monitored container. Then it collects and reports
+// statistics until Stop is called.
//
-// Public data fields should not be changed after calling Start.
+// Callers should not call Start more than once.
+//
+// Callers should not modify public data fields after calling Start.
func (r *Reporter) Start() {
r.done = make(chan struct{})
+ r.flushed = make(chan struct{})
go r.run()
}
-// Stop reporting statistics. Do not call more than once, or before
-// calling Start.
+// ReportPID starts reporting stats for a specified process.
+func (r *Reporter) ReportPID(name string, pid int) {
+ r.reportPIDsMu.Lock()
+ defer r.reportPIDsMu.Unlock()
+ if r.reportPIDs == nil {
+ r.reportPIDs = map[string]int{name: pid}
+ } else {
+ r.reportPIDs[name] = pid
+ }
+}
+
+// Stop reporting. Do not call more than once, or before calling
+// Start.
//
// Nothing will be logged after Stop returns.
func (r *Reporter) Stop() {
close(r.done)
+ <-r.flushed
}
func (r *Reporter) readAllOrWarn(in io.Reader) ([]byte, error) {
content, err := ioutil.ReadAll(in)
if err != nil {
- r.Logger.Print(err)
+ r.Logger.Printf("warning: %v", err)
}
return content, err
}
statsFilename := fmt.Sprintf("/proc/%s/net/dev", taskPid)
stats, err := ioutil.ReadFile(statsFilename)
if err != nil {
- r.Logger.Print(err)
+ r.Logger.Printf("notice: %v", err)
continue
}
return strings.NewReader(string(stats)), nil
return nil, errors.New("Could not read stats for any proc in container")
}
-type IoSample struct {
+type ioSample struct {
sampleTime time.Time
txBytes int64
rxBytes int64
}
-func (r *Reporter) DoBlkIoStats() {
+func (r *Reporter) doBlkIOStats() {
c, err := r.openStatFile("blkio", "blkio.io_service_bytes", true)
if err != nil {
return
defer c.Close()
b := bufio.NewScanner(c)
var sampleTime = time.Now()
- newSamples := make(map[string]IoSample)
+ newSamples := make(map[string]ioSample)
for b.Scan() {
var device, op string
var val int64
if _, err := fmt.Sscanf(string(b.Text()), "%s %s %d", &device, &op, &val); err != nil {
continue
}
- var thisSample IoSample
+ var thisSample ioSample
var ok bool
if thisSample, ok = newSamples[device]; !ok {
- thisSample = IoSample{sampleTime, -1, -1}
+ thisSample = ioSample{sampleTime, -1, -1}
}
switch op {
case "Read":
continue
}
delta := ""
- if prev, ok := r.lastDiskSample[dev]; ok {
+ if prev, ok := r.lastDiskIOSample[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)
}
r.Logger.Printf("blkio:%s %d write %d read%s\n", dev, sample.txBytes, sample.rxBytes, delta)
- r.lastDiskSample[dev] = sample
+ r.lastDiskIOSample[dev] = sample
}
}
-type MemSample struct {
+type memSample struct {
sampleTime time.Time
memStat map[string]int64
}
-func (r *Reporter) DoMemoryStats() {
+func (r *Reporter) doMemoryStats() {
c, err := r.openStatFile("memory", "memory.stat", true)
if err != nil {
return
}
defer c.Close()
b := bufio.NewScanner(c)
- thisSample := MemSample{time.Now(), make(map[string]int64)}
+ thisSample := memSample{time.Now(), make(map[string]int64)}
wantStats := [...]string{"cache", "swap", "pgmajfault", "rss"}
for b.Scan() {
var stat string
}
var outstat bytes.Buffer
for _, key := range wantStats {
- if val, ok := thisSample.memStat[key]; ok {
- outstat.WriteString(fmt.Sprintf(" %d %s", val, key))
+ // Use "total_X" stats (entire hierarchy) if enabled,
+ // otherwise just the single cgroup -- see
+ // https://www.kernel.org/doc/Documentation/cgroup-v1/memory.txt
+ if val, ok := thisSample.memStat["total_"+key]; ok {
+ fmt.Fprintf(&outstat, " %d %s", val, key)
+ } else if val, ok := thisSample.memStat[key]; ok {
+ fmt.Fprintf(&outstat, " %d %s", val, key)
}
}
r.Logger.Printf("mem%s\n", outstat.String())
+
+ if r.kernelPageSize == 0 {
+ // assign "don't try again" value in case we give up
+ // and return without assigning the real value
+ r.kernelPageSize = -1
+ buf, err := os.ReadFile("/proc/self/smaps")
+ if err != nil {
+ r.Logger.Printf("error reading /proc/self/smaps: %s", err)
+ return
+ }
+ m := regexp.MustCompile(`\nKernelPageSize:\s*(\d+) kB\n`).FindSubmatch(buf)
+ if len(m) != 2 {
+ r.Logger.Printf("error parsing /proc/self/smaps: KernelPageSize not found")
+ return
+ }
+ size, err := strconv.ParseInt(string(m[1]), 10, 64)
+ if err != nil {
+ r.Logger.Printf("error parsing /proc/self/smaps: KernelPageSize %q: %s", m[1], err)
+ return
+ }
+ r.kernelPageSize = size * 1024
+ } else if r.kernelPageSize < 0 {
+ // already failed to determine page size, don't keep
+ // trying/logging
+ return
+ }
+
+ r.reportPIDsMu.Lock()
+ defer r.reportPIDsMu.Unlock()
+ procnames := make([]string, 0, len(r.reportPIDs))
+ for name := range r.reportPIDs {
+ procnames = append(procnames, name)
+ }
+ sort.Strings(procnames)
+ procmem := ""
+ for _, procname := range procnames {
+ pid := r.reportPIDs[procname]
+ buf, err := os.ReadFile(fmt.Sprintf("/proc/%d/stat", pid))
+ if err != nil {
+ continue
+ }
+ // If the executable name contains a ')' char,
+ // /proc/$pid/stat will look like '1234 (exec name)) S
+ // 123 ...' -- the last ')' is the end of the 2nd
+ // field.
+ paren := bytes.LastIndexByte(buf, ')')
+ if paren < 0 {
+ continue
+ }
+ fields := bytes.SplitN(buf[paren:], []byte{' '}, 24)
+ if len(fields) < 24 {
+ continue
+ }
+ // rss is the 24th field in .../stat, and fields[0]
+ // here is the last char ')' of the 2nd field, so
+ // rss is fields[22]
+ rss, err := strconv.ParseInt(string(fields[22]), 10, 64)
+ if err != nil {
+ continue
+ }
+ procmem += fmt.Sprintf(" %d %s", rss*r.kernelPageSize, procname)
+ }
+ if procmem != "" {
+ r.Logger.Printf("procmem%s\n", procmem)
+ }
}
-func (r *Reporter) DoNetworkStats() {
+func (r *Reporter) doNetworkStats() {
sampleTime := time.Now()
stats, err := r.getContainerNetStats()
if err != nil {
if rx, err = strconv.ParseInt(words[1], 10, 64); err != nil {
continue
}
- nextSample := IoSample{}
+ nextSample := ioSample{}
nextSample.sampleTime = sampleTime
nextSample.txBytes = tx
nextSample.rxBytes = rx
}
}
-type CpuSample struct {
+type diskSpaceSample struct {
+ hasData bool
+ sampleTime time.Time
+ total uint64
+ used uint64
+ available uint64
+}
+
+func (r *Reporter) doDiskSpaceStats() {
+ s := syscall.Statfs_t{}
+ err := syscall.Statfs(r.TempDir, &s)
+ if err != nil {
+ return
+ }
+ bs := uint64(s.Bsize)
+ nextSample := diskSpaceSample{
+ hasData: true,
+ sampleTime: time.Now(),
+ total: s.Blocks * bs,
+ used: (s.Blocks - s.Bfree) * bs,
+ available: s.Bavail * bs,
+ }
+
+ var delta string
+ if r.lastDiskSpaceSample.hasData {
+ prev := r.lastDiskSpaceSample
+ interval := nextSample.sampleTime.Sub(prev.sampleTime).Seconds()
+ delta = fmt.Sprintf(" -- interval %.4f seconds %d used",
+ interval,
+ int64(nextSample.used-prev.used))
+ }
+ r.Logger.Printf("statfs %d available %d used %d total%s\n",
+ nextSample.available, nextSample.used, nextSample.total, delta)
+ r.lastDiskSpaceSample = nextSample
+}
+
+type cpuSample struct {
hasData bool // to distinguish the zero value from real data
sampleTime time.Time
user float64
// Return the number of CPUs available in the container. Return 0 if
// we can't figure out the real number of CPUs.
-func (r *Reporter) GetCpuCount() int64 {
+func (r *Reporter) getCPUCount() int64 {
cpusetFile, err := r.openStatFile("cpuset", "cpuset.cpus", true)
if err != nil {
return 0
}
defer cpusetFile.Close()
b, err := r.readAllOrWarn(cpusetFile)
+ if err != nil {
+ return 0
+ }
sp := strings.Split(string(b), ",")
cpus := int64(0)
for _, v := range sp {
if n == 2 {
cpus += (max - min) + 1
} else {
- cpus += 1
+ cpus++
}
}
return cpus
}
-func (r *Reporter) DoCpuStats() {
+func (r *Reporter) doCPUStats() {
statFile, err := r.openStatFile("cpuacct", "cpuacct.stat", true)
if err != nil {
return
return
}
- nextSample := CpuSample{true, time.Now(), 0, 0, r.GetCpuCount()}
var userTicks, sysTicks int64
fmt.Sscanf(string(b), "user %d\nsystem %d", &userTicks, &sysTicks)
- user_hz := float64(C.sysconf(C._SC_CLK_TCK))
- nextSample.user = float64(userTicks) / user_hz
- nextSample.sys = float64(sysTicks) / user_hz
+ userHz := float64(100)
+ nextSample := cpuSample{
+ hasData: true,
+ sampleTime: time.Now(),
+ user: float64(userTicks) / userHz,
+ sys: float64(sysTicks) / userHz,
+ cpus: r.getCPUCount(),
+ }
delta := ""
if r.lastCPUSample.hasData {
r.lastCPUSample = nextSample
}
-// Report stats periodically until r.done indicates someone called
-// Stop.
+// Report stats periodically until we learn (via r.done) that someone
+// called Stop.
func (r *Reporter) run() {
+ defer close(r.flushed)
+
r.reportedStatFile = make(map[string]string)
if !r.waitForCIDFile() || !r.waitForCgroup() {
return
}
- r.lastNetSample = make(map[string]IoSample)
- r.lastDiskSample = make(map[string]IoSample)
+ r.lastNetSample = make(map[string]ioSample)
+ r.lastDiskIOSample = make(map[string]ioSample)
- ticker := time.NewTicker(r.Poll)
+ if len(r.TempDir) == 0 {
+ // Temporary dir not provided, try to get it from the environment.
+ r.TempDir = os.Getenv("TMPDIR")
+ }
+ if len(r.TempDir) > 0 {
+ r.Logger.Printf("notice: monitoring temp dir %s\n", r.TempDir)
+ }
+
+ ticker := time.NewTicker(r.PollPeriod)
for {
- r.DoMemoryStats()
- r.DoCpuStats()
- r.DoBlkIoStats()
- r.DoNetworkStats()
+ r.doMemoryStats()
+ r.doCPUStats()
+ r.doBlkIOStats()
+ r.doNetworkStats()
+ r.doDiskSpaceStats()
select {
case <-r.done:
return
}
// If CID is empty, wait for it to appear in CIDFile. Return true if
-// we get it before r.done indicates someone called Stop.
+// we get it before we learn (via r.done) that someone called Stop.
func (r *Reporter) waitForCIDFile() bool {
- if r.CID != "" {
+ if r.CID != "" || r.CIDFile == "" {
return true
}
select {
case <-ticker.C:
case <-r.done:
- r.Logger.Printf("CID never appeared in %+q: %v", r.CIDFile, err)
+ r.Logger.Printf("warning: CID never appeared in %+q: %v", r.CIDFile, err)
return false
}
}
func (r *Reporter) waitForCgroup() bool {
ticker := time.NewTicker(100 * time.Millisecond)
defer ticker.Stop()
- warningTimer := time.After(r.Poll)
+ warningTimer := time.After(r.PollPeriod)
for {
c, err := r.openStatFile("cpuacct", "cgroup.procs", false)
if err == nil {
select {
case <-ticker.C:
case <-warningTimer:
- r.Logger.Printf("cgroup stats files have not appeared after %v (config error?) -- still waiting...", r.Poll)
+ r.Logger.Printf("warning: cgroup stats files have not appeared after %v (config error?) -- still waiting...", r.PollPeriod)
case <-r.done:
- r.Logger.Printf("cgroup stats files never appeared for %v", r.CID)
+ r.Logger.Printf("warning: cgroup stats files never appeared for %v", r.CID)
return false
}
}
projects / arvados.git / blobdiff