services/crunch/crunchstat/src/arvados.org/crunchstat/crunchstat.go

   1 package main
   2
   3 import (
   4         "bufio"
   5         "flag"
   6         "fmt"
   7         "io"
   8         "io/ioutil"
   9         "log"
  10         "os"
  11         "os/exec"
  12         "os/signal"
  13         "strings"
  14         "syscall"
  15         "time"
  16 )
  17
  18 func ReadLineByLine(inp io.ReadCloser, out chan string, finish chan bool) {
  19         s := bufio.NewScanner(inp)
  20         for s.Scan() {
  21                 out <- s.Text()
  22         }
  23         finish <- true
  24 }
  25
  26 func OutputChannel(stdout chan string, stderr chan string) {
  27         for {
  28                 select {
  29                 case s, ok := <-stdout:
  30                         if ok {
  31                                 fmt.Fprintln(os.Stdout, s)
  32                         } else {
  33                                 return
  34                         }
  35                 case s, ok := <-stderr:
  36                         if ok {
  37                                 fmt.Fprintln(os.Stderr, s)
  38                         } else {
  39                                 return
  40                         }
  41                 }
  42         }
  43 }
  44
  45 func FindStat(cgroup_path string, statgroup string, stat string) string {
  46         path := fmt.Sprintf("%s/%s.%s", cgroup_path, statgroup, stat)
  47         if _, err := os.Stat(path); err == nil {
  48                 return path
  49         }
  50         path = fmt.Sprintf("%s/%s/%s.%s", cgroup_path, statgroup, statgroup, stat)
  51         if _, err := os.Stat(path); err == nil {
  52                 return path
  53         }
  54         return ""
  55 }
  56
  57 func PollCgroupStats(cgroup_path string, stderr chan string, poll int64) {
  58         //var last_usage int64 = 0
  59         var last_user int64 = 0
  60         var last_sys int64 = 0
  61         var last_cpucount int64 = 0
  62
  63         type Disk struct {
  64                 last_read  int64
  65                 next_read  int64
  66                 last_write int64
  67                 next_write int64
  68         }
  69
  70         disk := make(map[string]*Disk)
  71
  72         //cpuacct_usage := FindStat(cgroup_path, "cpuacct", "usage")
  73         cpuacct_stat := FindStat(cgroup_path, "cpuacct", "stat")
  74         blkio_io_service_bytes := FindStat(cgroup_path, "blkio", "io_service_bytes")
  75         cpuset_cpus := FindStat(cgroup_path, "cpuset", "cpus")
  76         memory_stat := FindStat(cgroup_path, "memory", "stat")
  77
  78         if cpuacct_stat != "" {
  79                 stderr <- fmt.Sprintf("crunchstat: reading stats from %s", cpuacct_stat)
  80         }
  81         if blkio_io_service_bytes != "" {
  82                 stderr <- fmt.Sprintf("crunchstat: reading stats from %s", blkio_io_service_bytes)
  83         }
  84         if cpuset_cpus != "" {
  85                 stderr <- fmt.Sprintf("crunchstat: reading stats from %s", cpuset_cpus)
  86         }
  87         if memory_stat != "" {
  88                 stderr <- fmt.Sprintf("crunchstat: reading stats from %s", memory_stat)
  89         }
  90
  91         var elapsed int64 = poll
  92
  93         for {
  94                 /*{
  95                         c, _ := os.Open(cpuacct_usage)
  96                         b, _ := ioutil.ReadAll(c)
  97                         var next int64
  98                         fmt.Sscanf(string(b), "%d", &next)
  99                         if last_usage != 0 {
 100                                 stderr <- fmt.Sprintf("crunchstat: cpuacct.usage %v", (next-last_usage)/10000000)
 101                         }
 102                         //fmt.Printf("usage %d %d %d %d%%\n", last_usage, next, next-last_usage, (next-last_usage)/10000000)
 103                         last_usage = next
 104                         c.Close()
 105                 }*/
 106                 var cpus int64 = 0
 107                 if cpuset_cpus != "" {
 108                         c, _ := os.Open(cpuset_cpus)
 109                         b, _ := ioutil.ReadAll(c)
 110                         sp := strings.Split(string(b), ",")
 111                         for _, v := range sp {
 112                                 var min, max int64
 113                                 n, _ := fmt.Sscanf(v, "%d-%d", &min, &max)
 114                                 if n == 2 {
 115                                         cpus += (max - min) + 1
 116                                 } else {
 117                                         cpus += 1
 118                                 }
 119                         }
 120
 121                         if cpus != last_cpucount {
 122                                 stderr <- fmt.Sprintf("crunchstat: cpuset.cpus %v", cpus)
 123                         }
 124                         last_cpucount = cpus
 125
 126                         c.Close()
 127                 }
 128                 if cpus == 0 {
 129                         cpus = 1
 130                 }
 131                 if cpuacct_stat != "" {
 132                         c, _ := os.Open(cpuacct_stat)
 133                         b, _ := ioutil.ReadAll(c)
 134                         var next_user int64
 135                         var next_sys int64
 136                         fmt.Sscanf(string(b), "user %d\nsystem %d", &next_user, &next_sys)
 137                         c.Close()
 138
 139                         if last_user != 0 {
 140                                 user_diff := next_user - last_user
 141                                 sys_diff := next_sys - last_sys
 142                                 // Assume we're reading stats based on 100
 143                                 // jiffies per second.  Because the ellaspsed
 144                                 // time is in milliseconds, we need to boost
 145                                 // that to 1000 jiffies per second, then boost
 146                                 // it by another 100x to get a percentage, then
 147                                 // finally divide by the actual elapsed time
 148                                 // and the number of cpus to get average load
 149                                 // over the polling period.
 150                                 user_pct := (user_diff * 10 * 100) / (elapsed * cpus)
 151                                 sys_pct := (sys_diff * 10 * 100) / (elapsed * cpus)
 152
 153                                 stderr <- fmt.Sprintf("crunchstat: cpuacct.stat user %v", user_pct)
 154                                 stderr <- fmt.Sprintf("crunchstat: cpuacct.stat sys %v", sys_pct)
 155                         }
 156
 157                         /*fmt.Printf("user %d %d %d%%\n", last_user, next_user, next_user-last_user)
 158                         fmt.Printf("sys %d %d %d%%\n", last_sys, next_sys, next_sys-last_sys)
 159                         fmt.Printf("sum %d%%\n", (next_user-last_user)+(next_sys-last_sys))*/
 160                         last_user = next_user
 161                         last_sys = next_sys
 162                 }
 163                 if blkio_io_service_bytes != "" {
 164                         c, _ := os.Open(blkio_io_service_bytes)
 165                         b := bufio.NewScanner(c)
 166                         var device, op string
 167                         var next int64
 168                         for b.Scan() {
 169                                 if _, err := fmt.Sscanf(string(b.Text()), "%s %s %d", &device, &op, &next); err == nil {
 170                                         if disk[device] == nil {
 171                                                 disk[device] = new(Disk)
 172                                         }
 173                                         if op == "Read" {
 174                                                 disk[device].last_read = disk[device].next_read
 175                                                 disk[device].next_read = next
 176                                                 if disk[device].last_read > 0 {
 177                                                         stderr <- fmt.Sprintf("crunchstat: blkio.io_service_bytes %s read %v", device, disk[device].next_read-disk[device].last_read)
 178                                                 }
 179                                         }
 180                                         if op == "Write" {
 181                                                 disk[device].last_write = disk[device].next_write
 182                                                 disk[device].next_write = next
 183                                                 if disk[device].last_write > 0 {
 184                                                         stderr <- fmt.Sprintf("crunchstat: blkio.io_service_bytes %s write %v", device, disk[device].next_write-disk[device].last_write)
 185                                                 }
 186                                         }
 187                                 }
 188                         }
 189                         c.Close()
 190                 }
 191
 192                 if memory_stat != "" {
 193                         c, _ := os.Open(memory_stat)
 194                         b := bufio.NewScanner(c)
 195                         var stat string
 196                         var val int64
 197                         for b.Scan() {
 198                                 if _, err := fmt.Sscanf(string(b.Text()), "%s %d", &stat, &val); err == nil {
 199                                         if stat == "rss" {
 200                                                 stderr <- fmt.Sprintf("crunchstat: memory.stat rss %v", val)
 201                                         }
 202                                 }
 203                         }
 204                         c.Close()
 205                 }
 206
 207                 bedtime := time.Now()
 208                 time.Sleep(time.Duration(poll) * time.Millisecond)
 209                 morning := time.Now()
 210                 elapsed = morning.Sub(bedtime).Nanoseconds() / int64(time.Millisecond)
 211         }
 212 }
 213
 214 func main() {
 215
 216         var (
 217                 cgroup_path    string
 218                 cgroup_parent  string
 219                 cgroup_cidfile string
 220                 wait           int64
 221                 poll           int64
 222         )
 223
 224         flag.StringVar(&cgroup_path, "cgroup-path", "", "Direct path to cgroup")
 225         flag.StringVar(&cgroup_parent, "cgroup-parent", "", "Path to parent cgroup")
 226         flag.StringVar(&cgroup_cidfile, "cgroup-cid", "", "Path to container id file")
 227         flag.Int64Var(&wait, "wait", 5, "Maximum time (in seconds) to wait for cid file to show up")
 228         flag.Int64Var(&poll, "poll", 1000, "Polling frequency, in milliseconds")
 229
 230         flag.Parse()
 231
 232         logger := log.New(os.Stderr, "crunchstat: ", 0)
 233
 234         if cgroup_path == "" && cgroup_cidfile == "" {
 235                 logger.Fatal("Must provide either -cgroup-path or -cgroup-cid")
 236         }
 237
 238         // Make output channel
 239         stdout_chan := make(chan string)
 240         stderr_chan := make(chan string)
 241         finish_chan := make(chan bool)
 242         defer close(stdout_chan)
 243         defer close(stderr_chan)
 244         defer close(finish_chan)
 245
 246         go OutputChannel(stdout_chan, stderr_chan)
 247
 248         var cmd *exec.Cmd
 249
 250         if len(flag.Args()) > 0 {
 251                 // Set up subprocess
 252                 cmd = exec.Command(flag.Args()[0], flag.Args()[1:]...)
 253
 254                 logger.Print("Running ", flag.Args())
 255
 256                 // Forward SIGINT and SIGTERM to inner process
 257                 term := make(chan os.Signal, 1)
 258                 go func(sig <-chan os.Signal) {
 259                         catch := <-sig
 260                         if cmd.Process != nil {
 261                                 cmd.Process.Signal(catch)
 262                         }
 263                         logger.Print("caught signal:", catch)
 264                 }(term)
 265                 signal.Notify(term, syscall.SIGTERM)
 266                 signal.Notify(term, syscall.SIGINT)
 267
 268                 // Funnel stdout and stderr from subprocess to output channels
 269                 stdout_pipe, err := cmd.StdoutPipe()
 270                 if err != nil {
 271                         logger.Fatal(err)
 272                 }
 273                 go ReadLineByLine(stdout_pipe, stdout_chan, finish_chan)
 274
 275                 stderr_pipe, err := cmd.StderrPipe()
 276                 if err != nil {
 277                         logger.Fatal(err)
 278                 }
 279                 go ReadLineByLine(stderr_pipe, stderr_chan, finish_chan)
 280
 281                 // Run subprocess
 282                 if err := cmd.Start(); err != nil {
 283                         logger.Fatal(err)
 284                 }
 285         }
 286
 287         // Read the cid file
 288         if cgroup_cidfile != "" {
 289                 // wait up to 'wait' seconds for the cid file to appear
 290                 var i time.Duration
 291                 for i = 0; i < time.Duration(wait)*time.Second; i += (100 * time.Millisecond) {
 292                         f, err := os.Open(cgroup_cidfile)
 293                         if err == nil {
 294                                 cid, err2 := ioutil.ReadAll(f)
 295                                 if err2 == nil && len(cid) > 0 {
 296                                         cgroup_path = string(cid)
 297                                         f.Close()
 298                                         break
 299                                 }
 300                         }
 301                         time.Sleep(100 * time.Millisecond)
 302                 }
 303                 if cgroup_path == "" {
 304                         logger.Printf("Could not read cid file %s", cgroup_cidfile)
 305                 }
 306         }
 307
 308         // add the parent prefix
 309         if cgroup_parent != "" {
 310                 cgroup_path = fmt.Sprintf("%s/%s", cgroup_parent, cgroup_path)
 311         }
 312
 313         logger.Print("Using cgroup ", cgroup_path)
 314
 315         go PollCgroupStats(cgroup_path, stderr_chan, poll)
 316
 317         // Wait for each of stdout and stderr to drain
 318         <-finish_chan
 319         <-finish_chan
 320
 321         if err := cmd.Wait(); err != nil {
 322                 if exiterr, ok := err.(*exec.ExitError); ok {
 323                         // The program has exited with an exit code != 0
 324
 325                         // This works on both Unix and Windows. Although package
 326                         // syscall is generally platform dependent, WaitStatus is
 327                         // defined for both Unix and Windows and in both cases has
 328                         // an ExitStatus() method with the same signature.
 329                         if status, ok := exiterr.Sys().(syscall.WaitStatus); ok {
 330                                 os.Exit(status.ExitStatus())
 331                         }
 332                 } else {
 333                         logger.Fatalf("cmd.Wait: %v", err)
 334                 }
 335         }
 336 }