Add dmcache input plugin (#1667)

This commit is contained in:
Vladimir S 2017-04-08 01:39:43 +03:00 committed by Daniel Nelson
parent 223fce4770
commit a92ec65549
7 changed files with 456 additions and 0 deletions

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@ -64,6 +64,7 @@ be deprecated eventually.
- [#2587](https://github.com/influxdata/telegraf/pull/2587): Add json timestamp units configurability
- [#2597](https://github.com/influxdata/telegraf/issues/2597): Add support for Linux sysctl-fs metrics.
- [#2425](https://github.com/influxdata/telegraf/pull/2425): Support to include/exclude docker container labels as tags
- [#1667](https://github.com/influxdata/telegraf/pull/1667): dmcache input plugin
### Bugfixes

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@ -15,6 +15,7 @@ import (
_ "github.com/influxdata/telegraf/plugins/inputs/couchbase"
_ "github.com/influxdata/telegraf/plugins/inputs/couchdb"
_ "github.com/influxdata/telegraf/plugins/inputs/disque"
_ "github.com/influxdata/telegraf/plugins/inputs/dmcache"
_ "github.com/influxdata/telegraf/plugins/inputs/dns_query"
_ "github.com/influxdata/telegraf/plugins/inputs/docker"
_ "github.com/influxdata/telegraf/plugins/inputs/dovecot"

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@ -0,0 +1,47 @@
# DMCache Input Plugin
This plugin provide a native collection for dmsetup based statistics for dm-cache.
This plugin requires sudo, that is why you should setup and be sure that the telegraf is able to execute sudo without a password.
`sudo /sbin/dmsetup status --target cache` is the full command that telegraf will run for debugging purposes.
### Configuration
```toml
[[inputs.dmcache]]
## Whether to report per-device stats or not
per_device = true
```
### Measurements & Fields:
- dmcache
- length
- target
- metadata_blocksize
- metadata_used
- metadata_total
- cache_blocksize
- cache_used
- cache_total
- read_hits
- read_misses
- write_hits
- write_misses
- demotions
- promotions
- dirty
### Tags:
- All measurements have the following tags:
- device
### Example Output:
```
$ ./telegraf --test --config /etc/telegraf/telegraf.conf --input-filter dmcache
* Plugin: inputs.dmcache, Collection 1
> dmcache,device=example cache_blocksize=0i,read_hits=995134034411520i,read_misses=916807089127424i,write_hits=195107267543040i,metadata_used=12861440i,write_misses=563725346013184i,promotions=3265223720960i,dirty=0i,metadata_blocksize=0i,cache_used=1099511627776ii,cache_total=0i,length=0i,metadata_total=1073741824i,demotions=3265223720960i 1491482035000000000
```

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@ -0,0 +1,33 @@
package dmcache
import (
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/inputs"
)
type DMCache struct {
PerDevice bool `toml:"per_device"`
getCurrentStatus func() ([]string, error)
}
var sampleConfig = `
## Whether to report per-device stats or not
per_device = true
`
func (c *DMCache) SampleConfig() string {
return sampleConfig
}
func (c *DMCache) Description() string {
return "Provide a native collection for dmsetup based statistics for dm-cache"
}
func init() {
inputs.Add("dmcache", func() telegraf.Input {
return &DMCache{
PerDevice: true,
getCurrentStatus: dmSetupStatus,
}
})
}

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@ -0,0 +1,190 @@
// +build linux
package dmcache
import (
"os/exec"
"strconv"
"strings"
"errors"
"github.com/influxdata/telegraf"
)
const metricName = "dmcache"
type cacheStatus struct {
device string
length int
target string
metadataBlocksize int
metadataUsed int
metadataTotal int
cacheBlocksize int
cacheUsed int
cacheTotal int
readHits int
readMisses int
writeHits int
writeMisses int
demotions int
promotions int
dirty int
}
func (c *DMCache) Gather(acc telegraf.Accumulator) error {
outputLines, err := c.getCurrentStatus()
if err != nil {
return err
}
totalStatus := cacheStatus{}
for _, s := range outputLines {
status, err := parseDMSetupStatus(s)
if err != nil {
return err
}
if c.PerDevice {
tags := map[string]string{"device": status.device}
acc.AddFields(metricName, toFields(status), tags)
}
aggregateStats(&totalStatus, status)
}
acc.AddFields(metricName, toFields(totalStatus), map[string]string{"device": "all"})
return nil
}
func parseDMSetupStatus(line string) (cacheStatus, error) {
var err error
parseError := errors.New("Output from dmsetup could not be parsed")
status := cacheStatus{}
values := strings.Fields(line)
if len(values) < 15 {
return cacheStatus{}, parseError
}
status.device = strings.TrimRight(values[0], ":")
status.length, err = strconv.Atoi(values[2])
if err != nil {
return cacheStatus{}, err
}
status.target = values[3]
status.metadataBlocksize, err = strconv.Atoi(values[4])
if err != nil {
return cacheStatus{}, err
}
metadata := strings.Split(values[5], "/")
if len(metadata) != 2 {
return cacheStatus{}, parseError
}
status.metadataUsed, err = strconv.Atoi(metadata[0])
if err != nil {
return cacheStatus{}, err
}
status.metadataTotal, err = strconv.Atoi(metadata[1])
if err != nil {
return cacheStatus{}, err
}
status.cacheBlocksize, err = strconv.Atoi(values[6])
if err != nil {
return cacheStatus{}, err
}
cache := strings.Split(values[7], "/")
if len(cache) != 2 {
return cacheStatus{}, parseError
}
status.cacheUsed, err = strconv.Atoi(cache[0])
if err != nil {
return cacheStatus{}, err
}
status.cacheTotal, err = strconv.Atoi(cache[1])
if err != nil {
return cacheStatus{}, err
}
status.readHits, err = strconv.Atoi(values[8])
if err != nil {
return cacheStatus{}, err
}
status.readMisses, err = strconv.Atoi(values[9])
if err != nil {
return cacheStatus{}, err
}
status.writeHits, err = strconv.Atoi(values[10])
if err != nil {
return cacheStatus{}, err
}
status.writeMisses, err = strconv.Atoi(values[11])
if err != nil {
return cacheStatus{}, err
}
status.demotions, err = strconv.Atoi(values[12])
if err != nil {
return cacheStatus{}, err
}
status.promotions, err = strconv.Atoi(values[13])
if err != nil {
return cacheStatus{}, err
}
status.dirty, err = strconv.Atoi(values[14])
if err != nil {
return cacheStatus{}, err
}
return status, nil
}
func aggregateStats(totalStatus *cacheStatus, status cacheStatus) {
totalStatus.length += status.length
totalStatus.metadataBlocksize += status.metadataBlocksize
totalStatus.metadataUsed += status.metadataUsed
totalStatus.metadataTotal += status.metadataTotal
totalStatus.cacheBlocksize += status.cacheBlocksize
totalStatus.cacheUsed += status.cacheUsed
totalStatus.cacheTotal += status.cacheTotal
totalStatus.readHits += status.readHits
totalStatus.readMisses += status.readMisses
totalStatus.writeHits += status.writeHits
totalStatus.writeMisses += status.writeMisses
totalStatus.demotions += status.demotions
totalStatus.promotions += status.promotions
totalStatus.dirty += status.dirty
}
func toFields(status cacheStatus) map[string]interface{} {
fields := make(map[string]interface{})
fields["length"] = status.length
fields["metadata_blocksize"] = status.metadataBlocksize
fields["metadata_used"] = status.metadataUsed
fields["metadata_total"] = status.metadataTotal
fields["cache_blocksize"] = status.cacheBlocksize
fields["cache_used"] = status.cacheUsed
fields["cache_total"] = status.cacheTotal
fields["read_hits"] = status.readHits
fields["read_misses"] = status.readMisses
fields["write_hits"] = status.writeHits
fields["write_misses"] = status.writeMisses
fields["demotions"] = status.demotions
fields["promotions"] = status.promotions
fields["dirty"] = status.dirty
return fields
}
func dmSetupStatus() ([]string, error) {
out, err := exec.Command("/bin/sh", "-c", "sudo /sbin/dmsetup status --target cache").Output()
if err != nil {
return nil, err
}
if string(out) == "No devices found\n" {
return []string{}, nil
}
outString := strings.TrimRight(string(out), "\n")
status := strings.Split(outString, "\n")
return status, nil
}

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@ -0,0 +1,15 @@
// +build !linux
package dmcache
import (
"github.com/influxdata/telegraf"
)
func (c *DMCache) Gather(acc telegraf.Accumulator) error {
return nil
}
func dmSetupStatus() ([]string, error) {
return []string{}, nil
}

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@ -0,0 +1,169 @@
package dmcache
import (
"errors"
"testing"
"github.com/influxdata/telegraf/testutil"
"github.com/stretchr/testify/require"
)
var (
measurement = "dmcache"
badFormatOutput = []string{"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 "}
good2DevicesFormatOutput = []string{
"cs-1: 0 4883791872 cache 8 1018/1501122 512 7/464962 139 352643 15 46 0 7 0 1 writeback 2 migration_threshold 2048 mq 10 random_threshold 4 sequential_threshold 512 discard_promote_adjustment 1 read_promote_adjustment 4 write_promote_adjustment 8",
"cs-2: 0 4294967296 cache 8 72352/1310720 128 26/24327168 2409 286 265 524682 0 0 0 1 writethrough 2 migration_threshold 2048 mq 10 random_threshold 4 sequential_threshold 512 discard_promote_adjustment 1 read_promote_adjustment 4 write_promote_adjustment 8",
}
)
func TestPerDeviceGoodOutput(t *testing.T) {
var acc testutil.Accumulator
var plugin = &DMCache{
PerDevice: true,
getCurrentStatus: func() ([]string, error) {
return good2DevicesFormatOutput, nil
},
}
err := plugin.Gather(&acc)
require.NoError(t, err)
tags1 := map[string]string{
"device": "cs-1",
}
fields1 := map[string]interface{}{
"length": 4883791872,
"metadata_blocksize": 8,
"metadata_used": 1018,
"metadata_total": 1501122,
"cache_blocksize": 512,
"cache_used": 7,
"cache_total": 464962,
"read_hits": 139,
"read_misses": 352643,
"write_hits": 15,
"write_misses": 46,
"demotions": 0,
"promotions": 7,
"dirty": 0,
}
acc.AssertContainsTaggedFields(t, measurement, fields1, tags1)
tags2 := map[string]string{
"device": "cs-2",
}
fields2 := map[string]interface{}{
"length": 4294967296,
"metadata_blocksize": 8,
"metadata_used": 72352,
"metadata_total": 1310720,
"cache_blocksize": 128,
"cache_used": 26,
"cache_total": 24327168,
"read_hits": 2409,
"read_misses": 286,
"write_hits": 265,
"write_misses": 524682,
"demotions": 0,
"promotions": 0,
"dirty": 0,
}
acc.AssertContainsTaggedFields(t, measurement, fields2, tags2)
tags3 := map[string]string{
"device": "all",
}
fields3 := map[string]interface{}{
"length": 9178759168,
"metadata_blocksize": 16,
"metadata_used": 73370,
"metadata_total": 2811842,
"cache_blocksize": 640,
"cache_used": 33,
"cache_total": 24792130,
"read_hits": 2548,
"read_misses": 352929,
"write_hits": 280,
"write_misses": 524728,
"demotions": 0,
"promotions": 7,
"dirty": 0,
}
acc.AssertContainsTaggedFields(t, measurement, fields3, tags3)
}
func TestNotPerDeviceGoodOutput(t *testing.T) {
var acc testutil.Accumulator
var plugin = &DMCache{
PerDevice: false,
getCurrentStatus: func() ([]string, error) {
return good2DevicesFormatOutput, nil
},
}
err := plugin.Gather(&acc)
require.NoError(t, err)
tags := map[string]string{
"device": "all",
}
fields := map[string]interface{}{
"length": 9178759168,
"metadata_blocksize": 16,
"metadata_used": 73370,
"metadata_total": 2811842,
"cache_blocksize": 640,
"cache_used": 33,
"cache_total": 24792130,
"read_hits": 2548,
"read_misses": 352929,
"write_hits": 280,
"write_misses": 524728,
"demotions": 0,
"promotions": 7,
"dirty": 0,
}
acc.AssertContainsTaggedFields(t, measurement, fields, tags)
}
func TestNoDevicesOutput(t *testing.T) {
var acc testutil.Accumulator
var plugin = &DMCache{
PerDevice: true,
getCurrentStatus: func() ([]string, error) {
return []string{}, nil
},
}
err := plugin.Gather(&acc)
require.NoError(t, err)
}
func TestErrorDuringGettingStatus(t *testing.T) {
var acc testutil.Accumulator
var plugin = &DMCache{
PerDevice: true,
getCurrentStatus: func() ([]string, error) {
return nil, errors.New("dmsetup doesn't exist")
},
}
err := plugin.Gather(&acc)
require.Error(t, err)
}
func TestBadFormatOfStatus(t *testing.T) {
var acc testutil.Accumulator
var plugin = &DMCache{
PerDevice: true,
getCurrentStatus: func() ([]string, error) {
return badFormatOutput, nil
},
}
err := plugin.Gather(&acc)
require.Error(t, err)
}