feat(inputs.diskio): Add field io await and util

plugins/inputs/diskio/README.md

@@ -73,6 +73,9 @@ docker run --privileged -v /:/hostfs:ro -v /run/udev:/run/udev:ro -e HOST_PROC=/
     - iops_in_progress (integer, gauge)
     - merged_reads (integer, counter)
     - merged_writes (integer, counter)
+    - io_util (float64, gauge, percent)
+    - io_await (float64, gauge, milliseconds)
+    - io_svctm (float64, gauge, milliseconds)
 
 On linux these values correspond to the values in [`/proc/diskstats`][1] and
 [`/sys/block/<dev>/stat`][2].
@@ -123,6 +126,18 @@ efficiency.  Thus two 4K reads may become one 8K read before it is
 ultimately handed to the disk, and so it will be counted (and queued)
 as only one I/O. These fields lets you know how often this was done.
 
+### `io_await`
+
+The average time per I/O operation (ms)
+
+### `io_svctm`
+
+The service time per I/O operation, excluding wait time (ms)
+
+### `io_util`
+
+The percentage of time the disk was active (%)
+
 ## Sample Queries
 
 ### Calculate percent IO utilization per disk and host
@@ -147,3 +162,9 @@ diskio,name=sda1 merged_reads=0i,reads=2353i,writes=10i,write_bytes=2117632i,wri
 diskio,name=centos/var_log reads=1063077i,writes=591025i,read_bytes=139325491712i,write_bytes=144233131520i,read_time=650221i,write_time=24368817i,io_time=852490i,weighted_io_time=25037394i,iops_in_progress=1i,merged_reads=0i,merged_writes=0i 1578326400000000000
 diskio,name=sda write_time=49i,io_time=1317i,weighted_io_time=1404i,reads=2495i,read_time=1357i,write_bytes=2117632i,iops_in_progress=0i,merged_reads=0i,merged_writes=0i,writes=10i,read_bytes=38956544i 1578326400000000000
 ```
+
+```text
+diskio,name=sda io_await:0.3317307692307692,io_svctm:0.07692307692307693,io_util:0.5329780146568954 1578326400000000000
+diskio,name=sda1 io_await:0.3317307692307692,io_svctm:0.07692307692307693,io_util:0.5329780146568954 1578326400000000000
+diskio,name=sda2 io_await:0.3317307692307692,io_svctm:0.07692307692307693,io_util:0.5329780146568954 1578326400000000000
+```

plugins/inputs/diskio/diskio.go

@@ -6,6 +6,9 @@ import (
 	"fmt"
 	"regexp"
 	"strings"
+	"time"
+
+	"github.com/shirou/gopsutil/v3/disk"
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/filter"
@@ -32,11 +35,13 @@ type DiskIO struct {
 	SkipSerialNumber bool            `toml:"skip_serial_number"`
 	Log              telegraf.Logger `toml:"-"`
 
-	ps           system.PS
-	infoCache    map[string]diskInfoCache
-	deviceFilter filter.Filter
-	warnDiskName map[string]bool
-	warnDiskTags map[string]bool
+	ps                system.PS
+	infoCache         map[string]diskInfoCache
+	deviceFilter      filter.Filter
+	warnDiskName      map[string]bool
+	warnDiskTags      map[string]bool
+	lastIOCounterStat map[string]disk.IOCountersStat
+	lastCollectTime   time.Time
 }
 
 func (*DiskIO) SampleConfig() string {
@@ -57,6 +62,7 @@ func (d *DiskIO) Init() error {
 	d.infoCache = make(map[string]diskInfoCache)
 	d.warnDiskName = make(map[string]bool)
 	d.warnDiskTags = make(map[string]bool)
+	d.lastIOCounterStat = make(map[string]disk.IOCountersStat)
 
 	return nil
 }
@@ -73,8 +79,8 @@ func (d *DiskIO) Gather(acc telegraf.Accumulator) error {
 	if err != nil {
 		return fmt.Errorf("error getting disk io info: %w", err)
 	}
-
-	for _, io := range diskio {
+	collectTime := time.Now()
+	for k, io := range diskio {
 		match := false
 		if d.deviceFilter != nil && d.deviceFilter.Match(io.Name) {
 			match = true
@@ -125,9 +131,23 @@ func (d *DiskIO) Gather(acc telegraf.Accumulator) error {
 			"merged_reads":     io.MergedReadCount,
 			"merged_writes":    io.MergedWriteCount,
 		}
+		if lastValue, exists := d.lastIOCounterStat[k]; exists {
+			deltaRWCount := float64(io.ReadCount + io.WriteCount - lastValue.ReadCount - lastValue.WriteCount)
+			deltaRWTime := float64(io.ReadTime + io.WriteTime - lastValue.ReadTime - lastValue.WriteTime)
+			deltaIOTime := float64(io.IoTime - lastValue.IoTime)
+			if deltaRWCount > 0 {
+				fields["io_await"] = deltaRWTime / deltaRWCount
+				fields["io_svctm"] = deltaIOTime / deltaRWCount
+			}
+			itv := float64(collectTime.Sub(d.lastCollectTime).Milliseconds())
+			if itv > 0 {
+				fields["io_util"] = 100 * deltaIOTime / itv
+			}
+		}
 		acc.AddCounter("diskio", fields, tags)
 	}
-
+	d.lastCollectTime = collectTime
+	d.lastIOCounterStat = diskio
 	return nil
 }
 

plugins/inputs/diskio/diskio_test.go

@@ -2,6 +2,7 @@ package diskio
 
 import (
 	"testing"
+	"time"
 
 	"github.com/shirou/gopsutil/v3/disk"
 	"github.com/stretchr/testify/require"
@@ -127,3 +128,65 @@ func TestDiskIO(t *testing.T) {
 		})
 	}
 }
+
+func TestDiskIOUtil(t *testing.T) {
+	cts := map[string]disk.IOCountersStat{
+		"sda": {
+			ReadCount:        888,
+			WriteCount:       5341,
+			ReadBytes:        100000,
+			WriteBytes:       200000,
+			ReadTime:         7123,
+			WriteTime:        9087,
+			MergedReadCount:  11,
+			MergedWriteCount: 12,
+			Name:             "sda",
+			IoTime:           123552,
+			SerialNumber:     "ab-123-ad",
+		},
+	}
+
+	cts2 := map[string]disk.IOCountersStat{
+		"sda": {
+			ReadCount:        1000,
+			WriteCount:       6000,
+			ReadBytes:        200000,
+			WriteBytes:       300000,
+			ReadTime:         8123,
+			WriteTime:        9187,
+			MergedReadCount:  16,
+			MergedWriteCount: 30,
+			Name:             "sda",
+			IoTime:           163552,
+			SerialNumber:     "ab-123-ad",
+		},
+	}
+
+	var acc testutil.Accumulator
+	var mps system.MockPS
+	mps.On("DiskIO").Return(cts, nil)
+	diskio := &DiskIO{
+		Log:     testutil.Logger{},
+		Devices: []string{"sd*"},
+		ps:      &mps,
+	}
+	require.NoError(t, diskio.Init())
+	// gather
+	require.NoError(t, diskio.Gather(&acc))
+	// sleep
+	time.Sleep(1 * time.Second)
+	// gather twice
+	mps2 := system.MockPS{}
+	mps2.On("DiskIO").Return(cts2, nil)
+	diskio.ps = &mps2
+
+	err := diskio.Gather(&acc)
+	require.NoError(t, err)
+	require.True(t, acc.HasField("diskio", "io_util"), "miss io util")
+	require.True(t, acc.HasField("diskio", "io_svctm"), "miss io_svctm")
+	require.True(t, acc.HasField("diskio", "io_await"), "miss io_await")
+
+	require.True(t, acc.HasFloatField("diskio", "io_util"), "io_util not have value")
+	require.True(t, acc.HasFloatField("diskio", "io_svctm"), "io_svctm not have value")
+	require.True(t, acc.HasFloatField("diskio", "io_await"), "io_await not have value")
+}