logical_disk: remove the *_latency_seconds_total counters (#2763)

Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

internal/collector/logical_disk/AGENTS.md

@@ -26,7 +26,11 @@ multi-instance. These notes were recorded on a Windows Server 2025
   `rate(windows_logical_disk_{read,write}_seconds_total[5m])`.
 - `Avg. Disk sec/Read`, `/Write` and `/Transfer` are `PERF_AVERAGE_TIMER`.
   Their base is the operation count and equals `Disk Reads/sec` (3073),
-  `Disk Writes/sec` (1698) and their sum (4771).
+  `Disk Writes/sec` (1698) and their sum (4771). Their raw values duplicate the
+  busy time, so the collector no longer reads them; the former
+  `*_latency_seconds_total` counters were the busy time, not a latency. The
+  average latency is `rate(windows_logical_disk_read_seconds_total[5m]) /
+  rate(windows_logical_disk_reads_total[5m])`.
 - `% Idle Time` is a cumulative 100 ns timer as well, not a percentage.
   On `C:` it was 115960642 ticks, about 11.6 seconds.
 - `Disk Read Bytes/sec` and `Disk Write Bytes/sec` (`PERF_COUNTER_BULK_COUNT`)
@@ -52,9 +56,6 @@ Counters the collector reads:
 | `% Disk Write Time` | `PERF_PRECISION_100NS_TIMER` | 11319205 |  |
 | `% Free Space` | `PERF_RAW_FRACTION` | 49907 | 129254 |
 | `% Idle Time` | `PERF_PRECISION_100NS_TIMER` | 115960642 |  |
-| `Avg. Disk sec/Read` | `PERF_AVERAGE_TIMER` | 9858832 | 3073 |
-| `Avg. Disk sec/Transfer` | `PERF_AVERAGE_TIMER` | 21178037 | 4771 |
-| `Avg. Disk sec/Write` | `PERF_AVERAGE_TIMER` | 11319205 | 1698 |
 | `Current Disk Queue Length` | `PERF_COUNTER_RAWCOUNT` | 0 |  |
 | `Disk Read Bytes/sec` | `PERF_COUNTER_BULK_COUNT` | 131518976 |  |
 | `Disk Reads/sec` | `PERF_COUNTER_COUNTER` | 3073 |  |
@@ -66,6 +67,7 @@ Counters the collector reads:
 Not read by the collector:
 
 - `PERF_AVERAGE_BULK`: `Avg. Disk Bytes/Read`, `Avg. Disk Bytes/Transfer`, `Avg. Disk Bytes/Write`
+- `PERF_AVERAGE_TIMER`: `Avg. Disk sec/Read` (raw 9858832, base 3073), `Avg. Disk sec/Transfer` (raw 21178037, base 4771), `Avg. Disk sec/Write` (raw 11319205, base 1698)
 - `PERF_COUNTER_100NS_QUEUELEN_TYPE`: `Avg. Disk Queue Length`, `Avg. Disk Read Queue Length` (raw 9858832), `Avg. Disk Write Queue Length` (raw 11319205)
 - `PERF_COUNTER_BULK_COUNT`: `Disk Bytes/sec`
 - `PERF_COUNTER_COUNTER`: `Disk Transfers/sec`

internal/collector/logical_disk/logical_disk.go

@@ -94,22 +94,19 @@ type Collector struct {
 	// lastMountErr is the last logged error of getAllMountedVolumes.
 	lastMountErr string
 
-	freeSpace        *prometheus.Desc
-	idleTime         *prometheus.Desc
-	information      *prometheus.Desc
-	readBytesTotal   *prometheus.Desc
-	readLatency      *prometheus.Desc
-	readOnly         *prometheus.Desc
-	readsTotal       *prometheus.Desc
-	readTime         *prometheus.Desc
-	readWriteLatency *prometheus.Desc
-	requestsQueued   *prometheus.Desc
-	splitIOs         *prometheus.Desc
-	totalSpace       *prometheus.Desc
-	writeBytesTotal  *prometheus.Desc
-	writeLatency     *prometheus.Desc
-	writesTotal      *prometheus.Desc
-	writeTime        *prometheus.Desc
+	freeSpace       *prometheus.Desc
+	idleTime        *prometheus.Desc
+	information     *prometheus.Desc
+	readBytesTotal  *prometheus.Desc
+	readOnly        *prometheus.Desc
+	readsTotal      *prometheus.Desc
+	readTime        *prometheus.Desc
+	requestsQueued  *prometheus.Desc
+	splitIOs        *prometheus.Desc
+	totalSpace      *prometheus.Desc
+	writeBytesTotal *prometheus.Desc
+	writesTotal     *prometheus.Desc
+	writeTime       *prometheus.Desc
 
 	bitlockerStatus *prometheus.Desc
 }
@@ -289,27 +286,6 @@ func (c *Collector) Build(logger *slog.Logger, _ *mi.Session) error {
 		nil,
 	)
 
-	c.readLatency = prometheus.NewDesc(
-		prometheus.BuildFQName(types.Namespace, Name, "read_latency_seconds_total"),
-		"Shows the average time, in seconds, of a read operation from the disk (LogicalDisk.AvgDiskSecPerRead)",
-		[]string{"volume"},
-		nil,
-	)
-
-	c.writeLatency = prometheus.NewDesc(
-		prometheus.BuildFQName(types.Namespace, Name, "write_latency_seconds_total"),
-		"Shows the average time, in seconds, of a write operation to the disk (LogicalDisk.AvgDiskSecPerWrite)",
-		[]string{"volume"},
-		nil,
-	)
-
-	c.readWriteLatency = prometheus.NewDesc(
-		prometheus.BuildFQName(types.Namespace, Name, "read_write_latency_seconds_total"),
-		"Shows the time, in seconds, of the average disk transfer (LogicalDisk.AvgDiskSecPerTransfer)",
-		[]string{"volume"},
-		nil,
-	)
-
 	c.bitlockerStatus = prometheus.NewDesc(
 		prometheus.BuildFQName(types.Namespace, Name, "bitlocker_status"),
 		"BitLocker status for the logical disk",
@@ -463,27 +439,6 @@ func (c *Collector) Collect(ch chan<- prometheus.Metric, _ time.Duration) error
 				data.SplitIOPerSec,
 				data.Name,
 			)
-
-			ch <- prometheus.MustNewConstMetric(
-				c.readLatency,
-				prometheus.CounterValue,
-				data.AvgDiskSecPerRead*pdh.TicksToSecondScaleFactor,
-				data.Name,
-			)
-
-			ch <- prometheus.MustNewConstMetric(
-				c.writeLatency,
-				prometheus.CounterValue,
-				data.AvgDiskSecPerWrite*pdh.TicksToSecondScaleFactor,
-				data.Name,
-			)
-
-			ch <- prometheus.MustNewConstMetric(
-				c.readWriteLatency,
-				prometheus.CounterValue,
-				data.AvgDiskSecPerTransfer*pdh.TicksToSecondScaleFactor,
-				data.Name,
-			)
 		}
 
 		if c.bitlockerEnabled {

internal/collector/logical_disk/logical_disk_test.go

@@ -40,18 +40,22 @@ func TestCollector(t *testing.T) {
 	})
 }
 
-// TestCollectorAvgQueueRemoved checks that the removed avg_*_requests_queued gauges are
-// gone while their replacements are still emitted. The raw "Avg. Disk Read/Write Queue
-// Length" values were the same cumulative values as "% Disk Read/Write Time".
-func TestCollectorAvgQueueRemoved(t *testing.T) {
+// TestCollectorDuplicatesRemoved checks that the removed avg_*_requests_queued gauges and
+// *_latency_seconds_total counters are gone while their replacements are still emitted.
+// The raw "Avg. Disk Read/Write Queue Length" and "Avg. Disk sec/Read/Write/Transfer"
+// values were the same cumulative values as "% Disk Read/Write Time".
+func TestCollectorDuplicatesRemoved(t *testing.T) {
 	metrics := testutils.TestCollector(t, logical_disk.New, &logical_disk.Config{
 		CollectorsEnabled: logical_disk.ConfigDefaults.CollectorsEnabled,
 		VolumeInclude:     types.RegExpAny,
 	})
 
 	for removed, replacement := range map[string]string{
-		"windows_logical_disk_avg_read_requests_queued":  "windows_logical_disk_read_seconds_total",
-		"windows_logical_disk_avg_write_requests_queued": "windows_logical_disk_write_seconds_total",
+		"windows_logical_disk_avg_read_requests_queued":         "windows_logical_disk_read_seconds_total",
+		"windows_logical_disk_avg_write_requests_queued":        "windows_logical_disk_write_seconds_total",
+		"windows_logical_disk_read_latency_seconds_total":       "windows_logical_disk_read_seconds_total",
+		"windows_logical_disk_write_latency_seconds_total":      "windows_logical_disk_write_seconds_total",
+		"windows_logical_disk_read_write_latency_seconds_total": "windows_logical_disk_write_seconds_total",
 	} {
 		require.Empty(t, testutils.MetricValuesByLabel(metrics, removed, "volume"), "%s is still emitted", removed)
 		require.NotEmpty(t, testutils.MetricValuesByLabel(metrics, replacement, "volume"), "%s was not emitted", replacement)

internal/collector/logical_disk/types.go

@@ -20,9 +20,6 @@ package logical_disk
 type perfDataCounterValues struct {
 	Name string
 
-	AvgDiskSecPerRead      float64 `perfdata:"Avg. Disk sec/Read"`
-	AvgDiskSecPerTransfer  float64 `perfdata:"Avg. Disk sec/Transfer"`
-	AvgDiskSecPerWrite     float64 `perfdata:"Avg. Disk sec/Write"`
 	CurrentDiskQueueLength float64 `perfdata:"Current Disk Queue Length"`
 	FreeSpace              float64 `perfdata:"Free Megabytes"`
 	DiskReadBytesPerSec    float64 `perfdata:"Disk Read Bytes/sec"`

internal/metriccontract/metrics_test.go

@@ -86,9 +86,12 @@ var dynamicPrefixes = []string{
 //
 //nolint:gochecknoglobals
 var historicalReferences = map[string]string{
-	"windows_logical_disk_avg_read_requests_queued":  "docs/collector.logical_disk.md: removed in 0.32, use the read/write *_seconds_total rate",
-	"windows_logical_disk_avg_write_requests_queued": "docs/collector.logical_disk.md: removed in 0.32, use the read/write *_seconds_total rate",
-	"windows_net_route_info":                         "docs/collector.net.md: documented but never emitted, removed from the docs",
+	"windows_logical_disk_avg_read_requests_queued":         "docs/collector.logical_disk.md: removed in 0.32, use the read/write *_seconds_total rate",
+	"windows_logical_disk_avg_write_requests_queued":        "docs/collector.logical_disk.md: removed in 0.32, use the read/write *_seconds_total rate",
+	"windows_logical_disk_read_latency_seconds_total":       "docs/collector.logical_disk.md: removed in 0.32, duplicated read_seconds_total",
+	"windows_logical_disk_read_write_latency_seconds_total": "docs/collector.logical_disk.md: removed in 0.32, the sum of the read and write busy time",
+	"windows_logical_disk_write_latency_seconds_total":      "docs/collector.logical_disk.md: removed in 0.32, duplicated write_seconds_total",
+	"windows_net_route_info":                                "docs/collector.net.md: documented but never emitted, removed from the docs",
 }
 
 // ignoredReferences are windows_ names that are not metrics of the exporter.