Recognize exemplar record type in WAL watcher metrics (#11008)

* Add exemplar record case

Signed-off-by: Levi Harrison <git@leviharrison.dev>

* recordType() -> Type.String()

Signed-off-by: Levi Harrison <git@leviharrison.dev>

tsdb/record/record.go

@@ -44,6 +44,21 @@ const (
 	Exemplars Type = 4
 )
 
+func (rt Type) String() string {
+	switch rt {
+	case Series:
+		return "series"
+	case Samples:
+		return "samples"
+	case Exemplars:
+		return "exemplars"
+	case Tombstones:
+		return "tombstones"
+	default:
+		return "unknown"
+	}
+}
+
 // ErrNotFound is returned if a looked up resource was not found. Duplicate ErrNotFound from head.go.
 var ErrNotFound = errors.New("not found")
 

tsdb/wal/watcher.go

@@ -481,7 +481,7 @@ func (w *Watcher) readSegment(r *LiveReader, segmentNum int, tail bool) error {
 	)
 	for r.Next() && !isClosed(w.quit) {
 		rec := r.Record()
-		w.recordsReadMetric.WithLabelValues(recordType(dec.Type(rec))).Inc()
+		w.recordsReadMetric.WithLabelValues(dec.Type(rec).String()).Inc()
 
 		switch dec.Type(rec) {
 		case record.Series:
@@ -554,7 +554,7 @@ func (w *Watcher) readSegmentForGC(r *LiveReader, segmentNum int, _ bool) error
 	)
 	for r.Next() && !isClosed(w.quit) {
 		rec := r.Record()
-		w.recordsReadMetric.WithLabelValues(recordType(dec.Type(rec))).Inc()
+		w.recordsReadMetric.WithLabelValues(dec.Type(rec).String()).Inc()
 
 		switch dec.Type(rec) {
 		case record.Series:
@@ -583,19 +583,6 @@ func (w *Watcher) SetStartTime(t time.Time) {
 	w.startTimestamp = timestamp.FromTime(t)
 }
 
-func recordType(rt record.Type) string {
-	switch rt {
-	case record.Series:
-		return "series"
-	case record.Samples:
-		return "samples"
-	case record.Tombstones:
-		return "tombstones"
-	default:
-		return "unknown"
-	}
-}
-
 type segmentReadFn func(w *Watcher, r *LiveReader, segmentNum int, tail bool) error
 
 // Read all the series records from a Checkpoint directory.