Remote: Do not collect non-initialized timestamp metrics (#8060)

* Remote: Do not collect non-initialized timestamp metrics
Signed-off-by: NJulien Pivotto <roidelapluie@inuits.eu>

storage/remote/max_gauge.go → storage/remote/max_timestamp.go

@@ -19,13 +19,13 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 )
 
-type maxGauge struct {
+type maxTimestamp struct {
 	mtx   sync.Mutex
 	value float64
 	prometheus.Gauge
 }
 
-func (m *maxGauge) Set(value float64) {
+func (m *maxTimestamp) Set(value float64) {
 	m.mtx.Lock()
 	defer m.mtx.Unlock()
 	if value > m.value {
@@ -34,8 +34,14 @@ func (m *maxGauge) Set(value float64) {
 	}
 }
 
-func (m *maxGauge) Get() float64 {
+func (m *maxTimestamp) Get() float64 {
 	m.mtx.Lock()
 	defer m.mtx.Unlock()
 	return m.value
 }
+
+func (m *maxTimestamp) Collect(c chan<- prometheus.Metric) {
+	if m.Get() > 0 {
+		m.Gauge.Collect(c)
+	}
+}

storage/remote/queue_manager.go

@@ -56,7 +56,7 @@ type queueManagerMetrics struct {
 	droppedSamplesTotal   prometheus.Counter
 	enqueueRetriesTotal   prometheus.Counter
 	sentBatchDuration     prometheus.Histogram
-	highestSentTimestamp  *maxGauge
+	highestSentTimestamp  *maxTimestamp
 	pendingSamples        prometheus.Gauge
 	shardCapacity         prometheus.Gauge
 	numShards             prometheus.Gauge
@@ -118,7 +118,7 @@ func newQueueManagerMetrics(r prometheus.Registerer, rn, e string) *queueManager
 		Buckets:     append(prometheus.DefBuckets, 25, 60, 120, 300),
 		ConstLabels: constLabels,
 	})
-	m.highestSentTimestamp = &maxGauge{
+	m.highestSentTimestamp = &maxTimestamp{
 		Gauge: prometheus.NewGauge(prometheus.GaugeOpts{
 			Namespace:   namespace,
 			Subsystem:   subsystem,
@@ -262,7 +262,7 @@ type QueueManager struct {
 
 	metrics              *queueManagerMetrics
 	interner             *pool
-	highestRecvTimestamp *maxGauge
+	highestRecvTimestamp *maxTimestamp
 }
 
 // NewQueueManager builds a new QueueManager.
@@ -279,7 +279,7 @@ func NewQueueManager(
 	client WriteClient,
 	flushDeadline time.Duration,
 	interner *pool,
-	highestRecvTimestamp *maxGauge,
+	highestRecvTimestamp *maxTimestamp,
 ) *QueueManager {
 	if logger == nil {
 		logger = log.NewNopLogger()

storage/remote/queue_manager_test.go

@@ -47,8 +47,8 @@ import (
 
 const defaultFlushDeadline = 1 * time.Minute
 
-func newHighestTimestampMetric() *maxGauge {
-	return &maxGauge{
+func newHighestTimestampMetric() *maxTimestamp {
+	return &maxTimestamp{
 		Gauge: prometheus.NewGauge(prometheus.GaugeOpts{
 			Namespace: namespace,
 			Subsystem: subsystem,

storage/remote/write.go

@@ -53,7 +53,7 @@ type WriteStorage struct {
 	interner          *pool
 
 	// For timestampTracker.
-	highestTimestamp *maxGauge
+	highestTimestamp *maxTimestamp
 }
 
 // NewWriteStorage creates and runs a WriteStorage.
@@ -71,7 +71,7 @@ func NewWriteStorage(logger log.Logger, reg prometheus.Registerer, walDir string
 		samplesIn:         newEWMARate(ewmaWeight, shardUpdateDuration),
 		walDir:            walDir,
 		interner:          newPool(),
-		highestTimestamp: &maxGauge{
+		highestTimestamp: &maxTimestamp{
 			Gauge: prometheus.NewGauge(prometheus.GaugeOpts{
 				Namespace: namespace,
 				Subsystem: subsystem,
@@ -202,7 +202,7 @@ type timestampTracker struct {
 	writeStorage         *WriteStorage
 	samples              int64
 	highestTimestamp     int64
-	highestRecvTimestamp *maxGauge
+	highestRecvTimestamp *maxTimestamp
 }
 
 // Add implements storage.Appender.