telegraf/plugins/inputs/system/processes.go

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// +build !windows
package system
import (
"bytes"
"fmt"
"io/ioutil"
"log"
"os"
"os/exec"
"path/filepath"
"runtime"
"strconv"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/inputs"
)
type Processes struct {
execPS func() ([]byte, error)
readProcFile func(filename string) ([]byte, error)
forcePS bool
forceProc bool
}
func (p *Processes) Description() string {
return "Get the number of processes and group them by status"
}
func (p *Processes) SampleConfig() string { return "" }
func (p *Processes) Gather(acc telegraf.Accumulator) error {
// Get an empty map of metric fields
fields := getEmptyFields()
// Decide if we will use 'ps' to get stats (use procfs otherwise)
usePS := true
if runtime.GOOS == "linux" {
usePS = false
}
if p.forcePS {
usePS = true
} else if p.forceProc {
usePS = false
}
// Gather stats from 'ps' or procfs
if usePS {
if err := p.gatherFromPS(fields); err != nil {
return err
}
} else {
if err := p.gatherFromProc(fields); err != nil {
return err
}
}
acc.AddGauge("processes", fields, nil)
return nil
}
// Gets empty fields of metrics based on the OS
func getEmptyFields() map[string]interface{} {
fields := map[string]interface{}{
"blocked": int64(0),
"zombies": int64(0),
"stopped": int64(0),
"running": int64(0),
"sleeping": int64(0),
"total": int64(0),
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"unknown": int64(0),
}
switch runtime.GOOS {
case "freebsd":
fields["idle"] = int64(0)
fields["wait"] = int64(0)
case "darwin":
fields["idle"] = int64(0)
case "openbsd":
fields["idle"] = int64(0)
case "linux":
fields["paging"] = int64(0)
fields["total_threads"] = int64(0)
}
return fields
}
// exec `ps` to get all process states
func (p *Processes) gatherFromPS(fields map[string]interface{}) error {
out, err := p.execPS()
if err != nil {
return err
}
for i, status := range bytes.Fields(out) {
if i == 0 && string(status) == "STAT" {
// This is a header, skip it
continue
}
switch status[0] {
case 'W':
fields["wait"] = fields["wait"].(int64) + int64(1)
case 'U', 'D', 'L':
// Also known as uninterruptible sleep or disk sleep
fields["blocked"] = fields["blocked"].(int64) + int64(1)
case 'Z':
fields["zombies"] = fields["zombies"].(int64) + int64(1)
case 'T':
fields["stopped"] = fields["stopped"].(int64) + int64(1)
case 'R':
fields["running"] = fields["running"].(int64) + int64(1)
case 'S':
fields["sleeping"] = fields["sleeping"].(int64) + int64(1)
case 'I':
fields["idle"] = fields["idle"].(int64) + int64(1)
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case '?':
fields["unknown"] = fields["unknown"].(int64) + int64(1)
default:
log.Printf("I! processes: Unknown state [ %s ] from ps",
string(status[0]))
}
fields["total"] = fields["total"].(int64) + int64(1)
}
return nil
}
// get process states from /proc/(pid)/stat files
func (p *Processes) gatherFromProc(fields map[string]interface{}) error {
filenames, err := filepath.Glob("/proc/[0-9]*/stat")
if err != nil {
return err
}
for _, filename := range filenames {
_, err := os.Stat(filename)
data, err := p.readProcFile(filename)
if err != nil {
return err
}
if data == nil {
continue
}
// Parse out data after (<cmd name>)
i := bytes.LastIndex(data, []byte(")"))
if i == -1 {
continue
}
data = data[i+2:]
stats := bytes.Fields(data)
if len(stats) < 3 {
return fmt.Errorf("Something is terribly wrong with %s", filename)
}
switch stats[0][0] {
case 'R':
fields["running"] = fields["running"].(int64) + int64(1)
case 'S':
fields["sleeping"] = fields["sleeping"].(int64) + int64(1)
case 'D':
fields["blocked"] = fields["blocked"].(int64) + int64(1)
case 'Z':
fields["zombies"] = fields["zombies"].(int64) + int64(1)
case 'T', 't':
fields["stopped"] = fields["stopped"].(int64) + int64(1)
case 'W':
fields["paging"] = fields["paging"].(int64) + int64(1)
default:
log.Printf("I! processes: Unknown state [ %s ] in file %s",
string(stats[0][0]), filename)
}
fields["total"] = fields["total"].(int64) + int64(1)
threads, err := strconv.Atoi(string(stats[17]))
if err != nil {
log.Printf("I! processes: Error parsing thread count: %s", err)
continue
}
fields["total_threads"] = fields["total_threads"].(int64) + int64(threads)
}
return nil
}
func readProcFile(filename string) ([]byte, error) {
data, err := ioutil.ReadFile(filename)
if err != nil {
if os.IsNotExist(err) {
return nil, nil
}
return nil, err
}
return data, nil
}
func execPS() ([]byte, error) {
bin, err := exec.LookPath("ps")
if err != nil {
return nil, err
}
out, err := exec.Command(bin, "axo", "state").Output()
if err != nil {
return nil, err
}
return out, err
}
func init() {
inputs.Add("processes", func() telegraf.Input {
return &Processes{
execPS: execPS,
readProcFile: readProcFile,
}
})
}