add bcache plugin

This commit is contained in:
Roman Statsevich 2015-10-19 20:39:45 +03:00
parent b484703fe8
commit 0a49ee9323
2 changed files with 297 additions and 0 deletions

144
plugins/bcache/bcache.go Normal file
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package bcache
import (
"io/ioutil"
"os"
"path/filepath"
"strconv"
"strings"
"github.com/influxdb/telegraf/plugins"
)
type Bcache struct {
BcachePath string
BcacheDevs []string
}
var sampleConfig = `
# Bcache sets path
# If not specified, then default is:
# bcachePath = "/sys/fs/bcache"
#
# By default, telegraf gather stats for all bcache devices
# Setting devices will restrict the stats to the specified
# bcache devices.
# bcacheDevs = ["bcache0", ...]
`
func (b *Bcache) SampleConfig() string {
return sampleConfig
}
func (b *Bcache) Description() string {
return "Read metrics of bcache from stats_total and dirty_data"
}
func getBackingDevs(bcachePath string) []string {
bdevs, err := filepath.Glob(bcachePath + "/*/bdev*")
if len(bdevs) < 1 {
panic("Can't found any bcache device")
}
if err != nil {
panic(err)
}
return bdevs
}
func getTags(bdev string) map[string]string {
backingDevFile, _ := os.Readlink(bdev)
backingDevPath := strings.Split(backingDevFile, "/")
backingDev := backingDevPath[len(backingDevPath)-2]
bcacheDevFile, _ := os.Readlink(bdev + "/dev")
bcacheDevPath := strings.Split(bcacheDevFile, "/")
bcacheDev := bcacheDevPath[len(bcacheDevPath)-1]
return map[string]string{"backing_dev": backingDev, "bcache_dev": bcacheDev}
}
func prettyToBytes(v string) uint64 {
var factors = map[string]uint64{
"k": 1 << 10,
"M": 1 << 20,
"G": 1 << 30,
"T": 1 << 40,
"P": 1 << 50,
"E": 1 << 60,
}
var factor uint64
factor = 1
prefix := v[len(v)-1 : len(v)]
if factors[prefix] != 0 {
v = v[:len(v)-1]
factor = factors[prefix]
}
result, _ := strconv.ParseFloat(v, 32)
result = result * float64(factor)
return uint64(result)
}
func (b *Bcache) gatherBcache(bdev string, acc plugins.Accumulator) error {
tags := getTags(bdev)
metrics, err := filepath.Glob(bdev + "/stats_total/*")
if len(metrics) < 0 {
panic("Can't read any stats file")
}
file, err := ioutil.ReadFile(bdev + "/dirty_data")
if err != nil {
panic(err)
}
rawValue := strings.TrimSpace(string(file))
value := prettyToBytes(rawValue)
acc.Add("dirty_data", value, tags)
for _, path := range metrics {
key := filepath.Base(path)
file, err := ioutil.ReadFile(path)
rawValue := strings.TrimSpace(string(file))
if err != nil {
panic(err)
}
if key == "bypassed" {
value := prettyToBytes(rawValue)
acc.Add(key, value, tags)
} else {
value, _ := strconv.ParseUint(rawValue, 10, 64)
acc.Add(key, value, tags)
}
}
return nil
}
func (b *Bcache) Gather(acc plugins.Accumulator) error {
bcacheDevsChecked := make(map[string]bool)
var restrictDevs bool
if len(b.BcacheDevs) != 0 {
restrictDevs = true
for _, bcacheDev := range b.BcacheDevs {
bcacheDevsChecked[bcacheDev] = true
}
}
bcachePath := b.BcachePath
if len(bcachePath) == 0 {
bcachePath = "/sys/fs/bcache"
}
for _, bdev := range getBackingDevs(bcachePath) {
if restrictDevs {
bcacheDev := getTags(bdev)["bcache_dev"]
if !bcacheDevsChecked[bcacheDev] {
continue
}
}
b.gatherBcache(bdev, acc)
}
return nil
}
func init() {
plugins.Add("bcache", func() plugins.Plugin {
return &Bcache{}
})
}

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package bcache
import (
"io/ioutil"
"os"
"testing"
"github.com/influxdb/telegraf/testutil"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
const (
dirty_data = "1.5G"
bypassed = "4.7T"
cache_bypass_hits = "146155333"
cache_bypass_misses = "0"
cache_hit_ratio = "90"
cache_hits = "511469583"
cache_miss_collisions = "157567"
cache_misses = "50616331"
cache_readaheads = "2"
)
var (
testBcachePath = os.TempDir() + "/telegraf/sys/fs/bcache"
testBcacheUuidPath = testBcachePath + "/663955a3-765a-4737-a9fd-8250a7a78411"
testBcacheDevPath = os.TempDir() + "/telegraf/sys/devices/virtual/block/bcache0"
testBcacheBackingDevPath = os.TempDir() + "/telegraf/sys/devices/virtual/block/md10"
)
type metrics struct {
name string
value uint64
}
func TestBcacheGeneratesMetrics(t *testing.T) {
err := os.MkdirAll(testBcacheUuidPath, 0755)
require.NoError(t, err)
err = os.MkdirAll(testBcacheDevPath, 0755)
require.NoError(t, err)
err = os.MkdirAll(testBcacheBackingDevPath+"/bcache", 0755)
require.NoError(t, err)
err = os.Symlink(testBcacheBackingDevPath+"/bcache", testBcacheUuidPath+"/bdev0")
require.NoError(t, err)
err = os.Symlink(testBcacheDevPath, testBcacheUuidPath+"/bdev0/dev")
require.NoError(t, err)
err = os.MkdirAll(testBcacheUuidPath+"/bdev0/stats_total", 0755)
require.NoError(t, err)
err = ioutil.WriteFile(testBcacheUuidPath+"/bdev0/dirty_data", []byte(dirty_data), 0644)
require.NoError(t, err)
err = ioutil.WriteFile(testBcacheUuidPath+"/bdev0/stats_total/bypassed", []byte(bypassed), 0644)
require.NoError(t, err)
err = ioutil.WriteFile(testBcacheUuidPath+"/bdev0/stats_total/cache_bypass_hits", []byte(cache_bypass_hits), 0644)
require.NoError(t, err)
err = ioutil.WriteFile(testBcacheUuidPath+"/bdev0/stats_total/cache_bypass_misses", []byte(cache_bypass_misses), 0644)
require.NoError(t, err)
err = ioutil.WriteFile(testBcacheUuidPath+"/bdev0/stats_total/cache_hit_ratio", []byte(cache_hit_ratio), 0644)
require.NoError(t, err)
err = ioutil.WriteFile(testBcacheUuidPath+"/bdev0/stats_total/cache_hits", []byte(cache_hits), 0644)
require.NoError(t, err)
err = ioutil.WriteFile(testBcacheUuidPath+"/bdev0/stats_total/cache_miss_collisions", []byte(cache_miss_collisions), 0644)
require.NoError(t, err)
err = ioutil.WriteFile(testBcacheUuidPath+"/bdev0/stats_total/cache_misses", []byte(cache_misses), 0644)
require.NoError(t, err)
err = ioutil.WriteFile(testBcacheUuidPath+"/bdev0/stats_total/cache_readaheads", []byte(cache_readaheads), 0644)
require.NoError(t, err)
intMetrics := []*metrics{
{
name: "dirty_data",
value: 1610612736,
},
{
name: "bypassed",
value: 5167704440832,
},
{
name: "cache_bypass_hits",
value: 146155333,
},
{
name: "cache_bypass_misses",
value: 0,
},
{
name: "cache_hit_ratio",
value: 90,
},
{
name: "cache_hits",
value: 511469583,
},
{
name: "cache_miss_collisions",
value: 157567,
},
{
name: "cache_misses",
value: 50616331,
},
{
name: "cache_readaheads",
value: 2,
},
}
tags := map[string]string{
"backing_dev": "md10",
"bcache_dev": "bcache0",
}
var acc testutil.Accumulator
//all devs
b := &Bcache{BcachePath: testBcachePath}
err = b.Gather(&acc)
require.NoError(t, err)
for _, metric := range intMetrics {
assert.True(t, acc.HasUIntValue(metric.name), metric.name)
assert.True(t, acc.CheckTaggedValue(metric.name, metric.value, tags))
}
//one exist dev
b = &Bcache{BcachePath: testBcachePath, BcacheDevs: []string{"bcache0"}}
err = b.Gather(&acc)
require.NoError(t, err)
for _, metric := range intMetrics {
assert.True(t, acc.HasUIntValue(metric.name), metric.name)
assert.True(t, acc.CheckTaggedValue(metric.name, metric.value, tags))
}
err = os.RemoveAll(os.TempDir() + "/telegraf")
require.NoError(t, err)
}