adding ingestion delay metric

CHANGELOG.md

@@ -20,6 +20,7 @@
 * [ENHANCEMENT] Parquet Converter: Add a ring status page to expose the ring status. #7455
 * [ENHANCEMENT] Parquet: Add `-blocks-storage.bucket-store.parquet-query-concurrency` flag to configure the maximum number of concurrent goroutines applied at each level of parquet query processing in store-gateway: shard querying, row group processing, and column materialization. #7613
 * [ENHANCEMENT] Parquet: Add a row ranges cache for parquet query filtering in querier and store-gateway. #7478
+* [ENHANCEMENT] Ingester: Add `cortex_ingester_ingestion_delay_seconds` native histogram metric to track the delay between sample ingestion time and sample timestamp. #7443
 * [ENHANCEMENT] Ingester: Add WAL record metrics to help evaluate the effectiveness of WAL compression type (e.g. snappy, zstd): `cortex_ingester_tsdb_wal_record_part_writes_total`, `cortex_ingester_tsdb_wal_record_parts_bytes_written_total`, and `cortex_ingester_tsdb_wal_record_bytes_saved_total`. #7420
 * [ENHANCEMENT] Distributor: Introduce dynamic `Symbols` slice capacity pooling. #7398 #7401
 * [ENHANCEMENT] Metrics Helper: Add native histogram support for aggregating and merging, including dual-format histogram handling that exposes both native and classic bucket formats. #7359

pkg/ingester/ingester.go

@@ -1517,6 +1517,14 @@ func (i *Ingester) Push(ctx context.Context, req *cortexpb.WriteRequest) (*corte
 
 	var newSeries []labels.Labels
 
+	delayObserver := i.metrics.ingestionDelaySeconds.WithLabelValues(userID)
+	nowMs := time.Now().UnixMilli()
+	observeDelay := func(timestampMs int64) {
+		if delayMs := nowMs - timestampMs; delayMs >= 0 {
+			delayObserver.Observe(float64(delayMs) / 1000.0)
+		}
+	}
+
 	for _, ts := range req.Timeseries {
 		// The labels must be sorted (in our case, it's guaranteed a write request
 		// has sorted labels once hit the ingester).
@@ -1557,6 +1565,7 @@ func (i *Ingester) Push(ctx context.Context, req *cortexpb.WriteRequest) (*corte
 			if ref != 0 {
 				if _, err = app.Append(ref, copiedLabels, s.TimestampMs, s.Value); err == nil {
 					succeededSamplesCount++
+					observeDelay(s.TimestampMs)
 					continue
 				}
 
@@ -1568,6 +1577,7 @@ func (i *Ingester) Push(ctx context.Context, req *cortexpb.WriteRequest) (*corte
 						newSeries = append(newSeries, copiedLabels)
 					}
 					succeededSamplesCount++
+					observeDelay(s.TimestampMs)
 					continue
 				}
 			}
@@ -1615,6 +1625,7 @@ func (i *Ingester) Push(ctx context.Context, req *cortexpb.WriteRequest) (*corte
 				if ref != 0 {
 					if _, err = app.AppendHistogram(ref, copiedLabels, hp.TimestampMs, h, fh); err == nil {
 						succeededHistogramsCount++
+						observeDelay(hp.TimestampMs)
 						ingestedBucketsObserver.Observe(float64(hp.BucketCount()))
 						continue
 					}
@@ -1627,6 +1638,7 @@ func (i *Ingester) Push(ctx context.Context, req *cortexpb.WriteRequest) (*corte
 							newSeries = append(newSeries, copiedLabels)
 						}
 						succeededHistogramsCount++
+						observeDelay(hp.TimestampMs)
 						ingestedBucketsObserver.Observe(float64(hp.BucketCount()))
 						continue
 					}

pkg/ingester/ingester_test.go

@@ -2892,6 +2892,193 @@ func TestIngester_Push_OutOfOrderLabels(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestIngester_IngestionDelayMetric(t *testing.T) {
+	metricLabelAdapters := []cortexpb.LabelAdapter{{Name: labels.MetricName, Value: "test"}}
+	metricLabels := cortexpb.FromLabelAdaptersToLabels(metricLabelAdapters)
+
+	t.Run("float samples with delays", func(t *testing.T) {
+		registry := prometheus.NewRegistry()
+		cfg := defaultIngesterTestConfig(t)
+		cfg.LifecyclerConfig.JoinAfter = 0
+
+		ing, err := prepareIngesterWithBlocksStorage(t, cfg, registry)
+		require.NoError(t, err)
+		require.NoError(t, services.StartAndAwaitRunning(context.Background(), ing))
+		defer services.StopAndAwaitTerminated(context.Background(), ing) //nolint:errcheck
+
+		test.Poll(t, 100*time.Millisecond, ring.ACTIVE, func() any {
+			return ing.lifecycler.GetState()
+		})
+
+		userID := "user-1"
+		ctx := user.InjectOrgID(context.Background(), userID)
+
+		// Push samples with different delays (oldest first to avoid OOO)
+		now := time.Now().UnixMilli()
+		samples := []cortexpb.Sample{
+			{Value: 1, TimestampMs: now - 30000}, // 30 seconds ago
+			{Value: 2, TimestampMs: now - 10000}, // 10 seconds ago
+			{Value: 3, TimestampMs: now - 5000},  // 5 seconds ago
+		}
+
+		for _, sample := range samples {
+			req := cortexpb.ToWriteRequest(
+				[]labels.Labels{metricLabels},
+				[]cortexpb.Sample{sample},
+				nil,
+				nil,
+				cortexpb.API,
+			)
+			_, err = ing.Push(ctx, req)
+			require.NoError(t, err)
+		}
+
+		// Verify metric exists and has 3 observations
+		metricFamily, err := registry.Gather()
+		require.NoError(t, err)
+
+		var found bool
+		var sampleCount uint64
+		var sampleSum float64
+		for _, mf := range metricFamily {
+			if mf.GetName() == "cortex_ingester_ingestion_delay_seconds" {
+				for _, metric := range mf.GetMetric() {
+					for _, label := range metric.GetLabel() {
+						if label.GetName() == "user" && label.GetValue() == userID {
+							found = true
+							if metric.Histogram != nil {
+								sampleCount = metric.Histogram.GetSampleCount()
+								sampleSum = metric.Histogram.GetSampleSum()
+							}
+						}
+					}
+				}
+			}
+		}
+
+		require.True(t, found, "ingestion delay metric not found")
+		assert.Equal(t, uint64(3), sampleCount, "expected 3 observations")
+
+		// Verify delays were actually measured (sum should be positive and reasonable)
+		// We sent samples 30s, 10s, and 5s old, so total delay should be ~45s (with some execution time added)
+		assert.Greater(t, sampleSum, 40.0, "sum of delays should be at least 40s")
+	})
+
+	t.Run("future timestamps are filtered", func(t *testing.T) {
+		registry := prometheus.NewRegistry()
+		cfg := defaultIngesterTestConfig(t)
+		cfg.LifecyclerConfig.JoinAfter = 0
+
+		ing, err := prepareIngesterWithBlocksStorage(t, cfg, registry)
+		require.NoError(t, err)
+		require.NoError(t, services.StartAndAwaitRunning(context.Background(), ing))
+		defer services.StopAndAwaitTerminated(context.Background(), ing) //nolint:errcheck
+
+		test.Poll(t, 100*time.Millisecond, ring.ACTIVE, func() any {
+			return ing.lifecycler.GetState()
+		})
+
+		userID := "user-future"
+		ctx := user.InjectOrgID(context.Background(), userID)
+
+		// Push sample with future timestamp
+		futureTimestamp := time.Now().UnixMilli() + 60000 // 60 seconds in the future
+		req := cortexpb.ToWriteRequest(
+			[]labels.Labels{metricLabels},
+			[]cortexpb.Sample{{Value: 1, TimestampMs: futureTimestamp}},
+			nil,
+			nil,
+			cortexpb.API,
+		)
+
+		_, err = ing.Push(ctx, req)
+		require.NoError(t, err)
+
+		// Verify metric has 0 observations (future timestamp filtered)
+		metricFamily, err := registry.Gather()
+		require.NoError(t, err)
+
+		for _, mf := range metricFamily {
+			if mf.GetName() == "cortex_ingester_ingestion_delay_seconds" {
+				for _, metric := range mf.GetMetric() {
+					for _, label := range metric.GetLabel() {
+						if label.GetName() == "user" && label.GetValue() == userID {
+							if metric.Histogram != nil {
+								assert.Equal(t, uint64(0), metric.Histogram.GetSampleCount(),
+									"future timestamp should not be observed")
+							}
+						}
+					}
+				}
+			}
+		}
+	})
+
+	t.Run("per-user isolation", func(t *testing.T) {
+		registry := prometheus.NewRegistry()
+		cfg := defaultIngesterTestConfig(t)
+		cfg.LifecyclerConfig.JoinAfter = 0
+
+		ing, err := prepareIngesterWithBlocksStorage(t, cfg, registry)
+		require.NoError(t, err)
+		require.NoError(t, services.StartAndAwaitRunning(context.Background(), ing))
+		defer services.StopAndAwaitTerminated(context.Background(), ing) //nolint:errcheck
+
+		test.Poll(t, 100*time.Millisecond, ring.ACTIVE, func() any {
+			return ing.lifecycler.GetState()
+		})
+
+		// Push samples for two users
+		baseTime := time.Now().UnixMilli()
+		for _, u := range []struct {
+			id         string
+			numSamples int
+			delayMs    int64
+		}{
+			{"user-a", 2, 5000},
+			{"user-b", 3, 30000},
+		} {
+			ctx := user.InjectOrgID(context.Background(), u.id)
+			// Send in chronological order (oldest first)
+			for idx := u.numSamples - 1; idx >= 0; idx-- {
+				timestamp := baseTime - u.delayMs - int64(idx*1000)
+				req := cortexpb.ToWriteRequest(
+					[]labels.Labels{metricLabels},
+					[]cortexpb.Sample{{Value: float64(idx + 1), TimestampMs: timestamp}},
+					nil,
+					nil,
+					cortexpb.API,
+				)
+				_, err := ing.Push(ctx, req)
+				require.NoError(t, err)
+			}
+		}
+
+		// Verify each user has their own metric
+		metricFamily, err := registry.Gather()
+		require.NoError(t, err)
+
+		userCounts := make(map[string]uint64)
+		for _, mf := range metricFamily {
+			if mf.GetName() == "cortex_ingester_ingestion_delay_seconds" {
+				for _, metric := range mf.GetMetric() {
+					for _, label := range metric.GetLabel() {
+						if label.GetName() == "user" {
+							userID := label.GetValue()
+							if metric.Histogram != nil {
+								userCounts[userID] = metric.Histogram.GetSampleCount()
+							}
+						}
+					}
+				}
+			}
+		}
+
+		assert.Equal(t, uint64(2), userCounts["user-a"])
+		assert.Equal(t, uint64(3), userCounts["user-b"])
+	})
+}
+
 func BenchmarkIngesterPush(b *testing.B) {
 	limits := defaultLimitsTestConfig()
 	benchmarkIngesterPush(b, limits, false)

pkg/ingester/metrics.go

@@ -42,6 +42,7 @@ type ingesterMetrics struct {
 	ingestedExemplarsFail    prometheus.Counter
 	ingestedMetadataFail     prometheus.Counter
 	ingestedHistogramBuckets *prometheus.HistogramVec
+	ingestionDelaySeconds    *prometheus.HistogramVec
 	oooLabelsTotal           *prometheus.CounterVec
 	queries                  prometheus.Counter
 	queriedSamples           prometheus.Histogram
@@ -149,6 +150,14 @@ func newIngesterMetrics(r prometheus.Registerer,
 			NativeHistogramMinResetDuration: 1 * time.Hour,
 			Buckets:                         prometheus.ExponentialBuckets(1, 2, 10), // 1 to 512 buckets
 		}, []string{"user"}),
+		ingestionDelaySeconds: promauto.With(r).NewHistogramVec(prometheus.HistogramOpts{
+			Name:                            "cortex_ingester_ingestion_delay_seconds",
+			Help:                            "Delay in seconds between sample ingestion time and sample timestamp.",
+			NativeHistogramBucketFactor:     1.1,
+			NativeHistogramMaxBucketNumber:  100,
+			NativeHistogramMinResetDuration: 1,
+			Buckets:                         []float64{1, 5, 10, 30, 60, 120, 300, 600}, // 1s, 5s, 10s, 30s, 1m, 2m, 5m, 10m
+		}, []string{"user"}),
 		oooLabelsTotal: promauto.With(r).NewCounterVec(prometheus.CounterOpts{
 			Name: "cortex_ingester_out_of_order_labels_total",
 			Help: "The total number of out of order label found per user.",
@@ -413,6 +422,7 @@ func (m *ingesterMetrics) deletePerUserMetrics(userID string) {
 	m.limitsPerLabelSet.DeletePartialMatch(prometheus.Labels{"user": userID})
 	m.pushErrorsTotal.DeletePartialMatch(prometheus.Labels{"user": userID})
 	m.ingestedHistogramBuckets.DeleteLabelValues(userID)
+	m.ingestionDelaySeconds.DeleteLabelValues(userID)
 
 	if m.memSeriesCreatedTotal != nil {
 		m.memSeriesCreatedTotal.DeleteLabelValues(userID)