Add disk/weighted_io_time (Linux only) (#2312)

receiver/hostmetricsreceiver/hostmetrics_receiver_test.go

@@ -72,7 +72,7 @@ var resourceMetrics = []string{
 }
 
 var systemSpecificMetrics = map[string][]string{
-	"linux":   {"system.disk.merged", "system.filesystem.inodes.usage", "system.paging.faults", "system.processes.created", "system.processes.count"},
+	"linux":   {"system.disk.merged", "system.disk.weighted_io_time", "system.filesystem.inodes.usage", "system.paging.faults", "system.processes.created", "system.processes.count"},
 	"darwin":  {"system.filesystem.inodes.usage", "system.paging.faults", "system.processes.count"},
 	"freebsd": {"system.filesystem.inodes.usage", "system.paging.faults", "system.processes.count"},
 	"openbsd": {"system.filesystem.inodes.usage", "system.paging.faults", "system.processes.created", "system.processes.count"},

receiver/hostmetricsreceiver/internal/scraper/diskscraper/disk_metadata.go

@@ -82,6 +82,18 @@ var diskOperationTimeDescriptor = func() pdata.Metric {
 	return metric
 }()
 
+var diskWeightedIOTimeDescriptor = func() pdata.Metric {
+	metric := pdata.NewMetric()
+	metric.SetName("system.disk.weighted_io_time")
+	metric.SetDescription("Time disk spent activated multiplied by the queue length.")
+	metric.SetUnit("s")
+	metric.SetDataType(pdata.MetricDataTypeDoubleSum)
+	sum := metric.DoubleSum()
+	sum.SetIsMonotonic(true)
+	sum.SetAggregationTemporality(pdata.AggregationTemporalityCumulative)
+	return metric
+}()
+
 var diskPendingOperationsDescriptor = func() pdata.Metric {
 	metric := pdata.NewMetric()
 	metric.SetName("system.disk.pending_operations")

receiver/hostmetricsreceiver/internal/scraper/diskscraper/disk_scraper_others_linux.go

@@ -22,10 +22,27 @@ import (
 	"go.opentelemetry.io/collector/consumer/pdata"
 )
 
-const systemSpecificMetricsLen = 1
+const systemSpecificMetricsLen = 2
 
 func appendSystemSpecificMetrics(metrics pdata.MetricSlice, startIdx int, startTime, now pdata.TimestampUnixNano, ioCounters map[string]disk.IOCountersStat) {
-	metric := metrics.At(startIdx)
+	initializeDiskWeightedIOTimeMetric(metrics.At(startIdx+0), startTime, now, ioCounters)
+	initializeDiskMergedMetric(metrics.At(startIdx+1), startTime, now, ioCounters)
+}
+
+func initializeDiskWeightedIOTimeMetric(metric pdata.Metric, startTime, now pdata.TimestampUnixNano, ioCounters map[string]disk.IOCountersStat) {
+	diskWeightedIOTimeDescriptor.CopyTo(metric)
+
+	ddps := metric.DoubleSum().DataPoints()
+	ddps.Resize(len(ioCounters))
+
+	idx := 0
+	for device, ioCounter := range ioCounters {
+		initializeDoubleDataPoint(ddps.At(idx+0), startTime, now, device, "", float64(ioCounter.WeightedIO)/1e3)
+		idx++
+	}
+}
+
+func initializeDiskMergedMetric(metric pdata.Metric, startTime, now pdata.TimestampUnixNano, ioCounters map[string]disk.IOCountersStat) {
 	diskMergedDescriptor.CopyTo(metric)
 
 	idps := metric.IntSum().DataPoints()

receiver/hostmetricsreceiver/internal/scraper/diskscraper/disk_scraper_test.go

@@ -102,40 +102,35 @@ func TestScrape(t *testing.T) {
 				return
 			}
 
-			assert.GreaterOrEqual(t, metrics.Len(), 4)
+			assert.Equal(t, metricsLen, metrics.Len())
 
-			assertInt64DiskMetricValid(t, metrics.At(0), diskIODescriptor, true, test.expectedStartTime)
-			assertInt64DiskMetricValid(t, metrics.At(1), diskOperationsDescriptor, true, test.expectedStartTime)
+			assertInt64DiskMetricValid(t, metrics.At(0), diskIODescriptor, test.expectedStartTime)
+			assertInt64DiskMetricValid(t, metrics.At(1), diskOperationsDescriptor, test.expectedStartTime)
 			assertDoubleDiskMetricValid(t, metrics.At(2), diskIOTimeDescriptor, false, test.expectedStartTime)
 			assertDoubleDiskMetricValid(t, metrics.At(3), diskOperationTimeDescriptor, true, test.expectedStartTime)
 			assertDiskPendingOperationsMetricValid(t, metrics.At(4))
 
 			if runtime.GOOS == "linux" {
-				assertInt64DiskMetricValid(t, metrics.At(5), diskMergedDescriptor, true, test.expectedStartTime)
+				assertDoubleDiskMetricValid(t, metrics.At(5), diskWeightedIOTimeDescriptor, false, test.expectedStartTime)
+				assertInt64DiskMetricValid(t, metrics.At(6), diskMergedDescriptor, test.expectedStartTime)
 			}
 
 			internal.AssertSameTimeStampForAllMetrics(t, metrics)
 		})
 	}
 }
 
-func assertInt64DiskMetricValid(t *testing.T, metric pdata.Metric, expectedDescriptor pdata.Metric, expectDirectionLabels bool, startTime pdata.TimestampUnixNano) {
+func assertInt64DiskMetricValid(t *testing.T, metric pdata.Metric, expectedDescriptor pdata.Metric, startTime pdata.TimestampUnixNano) {
 	internal.AssertDescriptorEqual(t, expectedDescriptor, metric)
 	if startTime != 0 {
 		internal.AssertIntSumMetricStartTimeEquals(t, metric, startTime)
 	}
 
-	minExpectedPoints := 1
-	if expectDirectionLabels {
-		minExpectedPoints = 2
-	}
-	assert.GreaterOrEqual(t, metric.IntSum().DataPoints().Len(), minExpectedPoints)
+	assert.GreaterOrEqual(t, metric.IntSum().DataPoints().Len(), 2)
 
 	internal.AssertIntSumMetricLabelExists(t, metric, 0, deviceLabelName)
-	if expectDirectionLabels {
-		internal.AssertIntSumMetricLabelHasValue(t, metric, 0, directionLabelName, readDirectionLabelValue)
-		internal.AssertIntSumMetricLabelHasValue(t, metric, 1, directionLabelName, writeDirectionLabelValue)
-	}
+	internal.AssertIntSumMetricLabelHasValue(t, metric, 0, directionLabelName, readDirectionLabelValue)
+	internal.AssertIntSumMetricLabelHasValue(t, metric, 1, directionLabelName, writeDirectionLabelValue)
 }
 
 func assertDoubleDiskMetricValid(t *testing.T, metric pdata.Metric, expectedDescriptor pdata.Metric, expectDirectionLabels bool, startTime pdata.TimestampUnixNano) {