follow-up for 2a12f948a97173ec8bf4c900e6725712021ef737

This commit is contained in:
Aliaksandr Valialkin 2021-02-04 16:28:55 +02:00
parent 2a12f948a9
commit c070763356
4 changed files with 56 additions and 52 deletions

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@ -58,11 +58,17 @@ func WritePrometheus(w io.Writer, exposeProcessMetrics bool) {
// metrics.WriteProcessMetrics(w)
// })
//
// See also WrteFDMetrics.
func WriteProcessMetrics(w io.Writer) {
writeGoMetrics(w)
writeProcessMetrics(w)
}
// WriteFDMetrics writes `process_max_fds` and `process_open_fds` metrics to w.
func WriteFDMetrics(w io.Writer) {
writeFDMetrics(w)
}
// UnregisterMetric removes metric with the given name from default set.
func UnregisterMetric(name string) bool {
return defaultSet.UnregisterMetric(name)

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@ -8,7 +8,6 @@ import (
"io/ioutil"
"log"
"os"
"regexp"
"strconv"
"strings"
"time"
@ -87,74 +86,70 @@ func writeProcessMetrics(w io.Writer) {
var startTimeSeconds = time.Now().Unix()
const fdReadChunkSize = 512
func WriteFDMetrics(w io.Writer){
// WriteFDMetrics writes process_max_fds and process_open_fds metrics to w.
func writeFDMetrics(w io.Writer) {
totalOpenFDs, err := getOpenFDsCount("/proc/self/fd")
if err != nil {
log.Printf("ERROR: %v",err)
log.Printf("ERROR: cannot determine open file descriptors count: %s", err)
return
}
maxOpenFDs, err := getMaxFilesLimit("/proc/self/limits")
if err != nil {
log.Printf("ERROR: %v",err)
log.Printf("ERROR: cannot determine the limit on open file descritors: %s", err)
return
}
fmt.Fprintf(w,"process_max_fds %d\n",maxOpenFDs)
fmt.Fprintf(w,"process_open_fds %d\n",totalOpenFDs)
fmt.Fprintf(w, "process_max_fds %d\n", maxOpenFDs)
fmt.Fprintf(w, "process_open_fds %d\n", totalOpenFDs)
}
func getOpenFDsCount(path string)(uint64,error){
func getOpenFDsCount(path string) (uint64, error) {
f, err := os.Open(path)
if err != nil {
return 0,fmt.Errorf("cannot open process fd path: %q, err: %v",path,err)
return 0, err
}
defer f.Close()
var totalOpenFDs uint64
for {
names, err := f.Readdirnames(fdReadChunkSize)
if err == io.EOF{
names, err := f.Readdirnames(512)
if err == io.EOF {
break
}
if err != nil {
return 0, fmt.Errorf("unexpected error at readdirnames: %v",err)
return 0, fmt.Errorf("unexpected error at Readdirnames: %s", err)
}
totalOpenFDs += uint64(len(names))
}
return totalOpenFDs, nil
}
var limitsRe = regexp.MustCompile(`(Max \w+\s{0,1}?\w*\s{0,1}\w*)\s{2,}(\w+)\s+(\w+)`)
func getMaxFilesLimit(path string)(uint64,error){
func getMaxFilesLimit(path string) (uint64, error) {
f, err := os.Open(path)
if err != nil {
return 0,fmt.Errorf("cannot open path: %q for max files limit, err: %w",path,err)
return 0, err
}
defer f.Close()
prefix := "Max open files"
scan := bufio.NewScanner(f)
// skip first line
scan.Scan()
for scan.Scan(){
text := scan.Text()
if !strings.HasPrefix(text,"Max open files"){
for scan.Scan() {
s := scan.Text()
if !strings.HasPrefix(s, prefix) {
continue
}
items := limitsRe.FindStringSubmatch(text)
if len(items) != 4 {
return 0,fmt.Errorf("unxpected fields num for limits file, want: %d, got: %d, line: %q",4,len(items),text)
text := strings.TrimSpace(s[len(prefix):])
// Extract soft limit.
n := strings.IndexByte(text, ' ')
if n < 0 {
return 0, fmt.Errorf("cannot extract soft limit from %q", s)
}
// use soft limit.
limit := items[2]
if limit == "unlimited"{
return 18446744073709551615,nil
text = text[:n]
if text == "unlimited" {
return 1<<64 - 1, nil
}
limitUint, err := strconv.ParseUint(limit,10,64)
limit, err := strconv.ParseUint(text, 10, 64)
if err != nil {
return 0, fmt.Errorf("cannot parse limit: %q as uint64: %w",limit,err)
return 0, fmt.Errorf("cannot parse soft limit from %q: %s", s, err)
}
return limitUint,nil
return limit, nil
}
return 0, fmt.Errorf("max open files limit wasn't found")
return 0, fmt.Errorf("cannot find max open files limit")
}

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@ -2,36 +2,35 @@ package metrics
import "testing"
func TestGetMaxFilesLimit(t *testing.T){
f := func(want uint64,path string, wantErr bool) {
func TestGetMaxFilesLimit(t *testing.T) {
f := func(want uint64, path string, wantErr bool) {
t.Helper()
got, err := getMaxFilesLimit(path)
if err != nil && !wantErr {
t.Fatalf("unexpected error: %v",err)
t.Fatalf("unexpected error: %v", err)
}
if got != want{
t.Fatalf("unexpected result: %d, want: %d at getMaxFilesLimit",got,want)
if got != want {
t.Fatalf("unexpected result: %d, want: %d at getMaxFilesLimit", got, want)
}
}
f(1024,"testdata/limits",false)
f(0,"testdata/bad_path",true)
f(0,"testdata/limits_bad",true)
f(1024, "testdata/limits", false)
f(0, "testdata/bad_path", true)
f(0, "testdata/limits_bad", true)
}
func TestGetOpenFDsCount(t *testing.T){
f := func(want uint64,path string, wantErr bool) {
func TestGetOpenFDsCount(t *testing.T) {
f := func(want uint64, path string, wantErr bool) {
t.Helper()
got, err := getOpenFDsCount(path)
if (err != nil && !wantErr)|| (err == nil && wantErr) {
t.Fatalf("unexpected error: %v",err)
if (err != nil && !wantErr) || (err == nil && wantErr) {
t.Fatalf("unexpected error: %v", err)
}
if got != want{
t.Fatalf("unexpected result: %d, want: %d at getOpenFDsCount",got,want)
if got != want {
t.Fatalf("unexpected result: %d, want: %d at getOpenFDsCount", got, want)
}
}
f(5,"testdata/fd/",false)
f(0,"testdata/fd/0",true)
f(0,"testdata/limits",true)
f(5, "testdata/fd/", false)
f(0, "testdata/fd/0", true)
f(0, "testdata/limits", true)
}

View File

@ -9,3 +9,7 @@ import (
func writeProcessMetrics(w io.Writer) {
// TODO: implement it
}
func writeFDMetrics(w io.Writer) {
// TODO: implement it.
}