fix: handle series with different types of labels

pkg/modules/metricsexplorer/implmetricsexplorer/module.go

@@ -138,14 +138,7 @@ func (m *module) listMeterMetrics(ctx context.Context, params *metricsexplorerty
 
 func (m *module) listMetrics(ctx context.Context, orgID valuer.UUID, params *metricsexplorertypes.ListMetricsParams) (*metricsexplorertypes.ListMetricsResponse, error) {
 	sb := sqlbuilder.NewSelectBuilder()
-	sb.Select(
-		"metric_name",
-		"anyLast(description) AS description",
-		"anyLast(type) AS metric_type",
-		"argMax(unit, unix_milli) AS metric_unit",
-		"anyLast(temporality) AS temporality",
-		"anyLast(is_monotonic) AS is_monotonic",
-	)
+	sb.Select("DISTINCT metric_name")
 
 	if params.Start != nil && params.End != nil {
 		start, end, distributedTsTable, _ := telemetrymetrics.WhichTSTableToUse(uint64(*params.Start), uint64(*params.End), nil)
@@ -164,7 +157,6 @@ func (m *module) listMetrics(ctx context.Context, orgID valuer.UUID, params *met
 		sb.Where(sb.Like("lower(metric_name)", fmt.Sprintf("%%%s%%", searchLower)))
 	}
 
-	sb.GroupBy("metric_name")
 	sb.OrderBy("metric_name ASC")
 	sb.Limit(params.Limit)
 
@@ -178,47 +170,43 @@ func (m *module) listMetrics(ctx context.Context, orgID valuer.UUID, params *met
 	}
 	defer rows.Close()
 
-	var metrics []metricsexplorertypes.ListMetric
-	var metricNames []string
+	metricNames := make([]string, 0)
 	for rows.Next() {
-		var metric metricsexplorertypes.ListMetric
-		if err := rows.Scan(
-			&metric.MetricName,
-			&metric.Description,
-			&metric.MetricType,
-			&metric.MetricUnit,
-			&metric.Temporality,
-			&metric.IsMonotonic,
-		); err != nil {
-			return nil, errors.WrapInternalf(err, errors.CodeInternal, "failed to scan metric")
+		var name string
+		if err := rows.Scan(&name); err != nil {
+			return nil, errors.WrapInternalf(err, errors.CodeInternal, "failed to scan metric name")
 		}
-		metrics = append(metrics, metric)
-		metricNames = append(metricNames, metric.MetricName)
+		metricNames = append(metricNames, name)
 	}
 
 	if err := rows.Err(); err != nil {
-		return nil, errors.WrapInternalf(err, errors.CodeInternal, "error iterating metrics")
+		return nil, errors.WrapInternalf(err, errors.CodeInternal, "error iterating metric names")
 	}
 
-	if len(metrics) == 0 {
+	if len(metricNames) == 0 {
 		return &metricsexplorertypes.ListMetricsResponse{
 			Metrics: []metricsexplorertypes.ListMetric{},
 		}, nil
 	}
 
-	// Overlay any user-updated metadata on top of the timeseries metadata.
-	updatedMetadata, err := m.fetchUpdatedMetadata(ctx, orgID, metricNames)
+	metadata, err := m.GetMetricMetadataMulti(ctx, orgID, metricNames)
 	if err != nil {
 		return nil, err
 	}
-	for i := range metrics {
-		if meta, ok := updatedMetadata[metrics[i].MetricName]; ok && meta != nil {
-			metrics[i].Description = meta.Description
-			metrics[i].MetricType = meta.MetricType
-			metrics[i].MetricUnit = meta.MetricUnit
-			metrics[i].Temporality = meta.Temporality
-			metrics[i].IsMonotonic = meta.IsMonotonic
+
+	metrics := make([]metricsexplorertypes.ListMetric, 0, len(metricNames))
+	for _, name := range metricNames {
+		metric := metricsexplorertypes.ListMetric{
+			MetricName: name,
 		}
+		if meta, ok := metadata[name]; ok && meta != nil {
+			metric.Description = meta.Description
+			metric.MetricType = meta.MetricType
+			metric.MetricUnit = meta.MetricUnit
+			metric.Temporality = meta.Temporality
+			metric.IsMonotonic = meta.IsMonotonic
+		}
+		metrics = append(metrics, metric)
 	}
 
 	return &metricsexplorertypes.ListMetricsResponse{
@@ -255,18 +243,19 @@ func (m *module) GetStats(ctx context.Context, orgID valuer.UUID, req *metricsex
 		}, nil
 	}
 
-	// Overlay any user-updated metadata on top of the timeseries metadata
-	// that was already fetched in the combined query.
+	// Get metadata for all metrics
 	metricNames := make([]string, len(metricStats))
 	for i := range metricStats {
 		metricNames[i] = metricStats[i].MetricName
 	}
 
-	updatedMetadata, err := m.fetchUpdatedMetadata(ctx, orgID, metricNames)
+	metadata, err := m.GetMetricMetadataMulti(ctx, orgID, metricNames)
 	if err != nil {
 		return nil, err
 	}
-	enrichStatsWithMetadata(metricStats, updatedMetadata)
+
+	// Enrich stats with metadata
+	enrichStatsWithMetadata(metricStats, metadata)
 
 	return &metricsexplorertypes.StatsResponse{
 		Metrics: metricStats,
@@ -995,14 +984,11 @@ func (m *module) fetchMetricsStatsWithSamples(
 	samplesTable := telemetrymetrics.WhichSamplesTableToUse(uint64(req.Start), uint64(req.End), metrictypes.UnspecifiedType, metrictypes.TimeAggregationUnspecified, nil)
 	countExp := telemetrymetrics.CountExpressionForSamplesTable(samplesTable)
 
-	// Timeseries counts and metadata per metric.
+	// Timeseries counts per metric
 	tsSB := sqlbuilder.NewSelectBuilder()
 	tsSB.Select(
 		"metric_name",
 		"uniq(fingerprint) AS timeseries",
-		"anyLast(description) AS description",
-		"anyLast(type) AS metric_type",
-		"argMax(unit, unix_milli) AS metric_unit",
 	)
 	tsSB.From(fmt.Sprintf("%s.%s", telemetrymetrics.DBName, distributedTsTable))
 	tsSB.Where(tsSB.Between("unix_milli", start, end))
@@ -1050,9 +1036,6 @@ func (m *module) fetchMetricsStatsWithSamples(
 		"COALESCE(ts.timeseries, 0) AS timeseries",
 		"COALESCE(s.samples, 0) AS samples",
 		"COUNT(*) OVER() AS total",
-		"ts.description AS description",
-		"ts.metric_type AS metric_type",
-		"ts.metric_unit AS metric_unit",
 	)
 	finalSB.From("__time_series_counts ts")
 	finalSB.JoinWithOption(sqlbuilder.FullOuterJoin, "__sample_counts s", "ts.metric_name = s.metric_name")
@@ -1088,7 +1071,7 @@ func (m *module) fetchMetricsStatsWithSamples(
 			metricStat metricsexplorertypes.Stat
 			rowTotal   uint64
 		)
-		if err := rows.Scan(&metricStat.MetricName, &metricStat.TimeSeries, &metricStat.Samples, &rowTotal, &metricStat.Description, &metricStat.MetricType, &metricStat.MetricUnit); err != nil {
+		if err := rows.Scan(&metricStat.MetricName, &metricStat.TimeSeries, &metricStat.Samples, &rowTotal); err != nil {
 			return nil, 0, errors.WrapInternalf(err, errors.CodeInternal, "failed to scan metrics stats row")
 		}
 		metricStats = append(metricStats, metricStat)

pkg/querier/postprocess.go

@@ -627,19 +627,29 @@ func convertTimeSeriesDataToScalar(tsData *qbtypes.TimeSeriesData, queryName str
 		return &qbtypes.ScalarData{QueryName: queryName}
 	}
 
-	columns := []*qbtypes.ColumnDescriptor{}
-
-	// Add group columns from first series
-	if len(tsData.Aggregations[0].Series) > 0 {
-		for _, label := range tsData.Aggregations[0].Series[0].Labels {
-			columns = append(columns, &qbtypes.ColumnDescriptor{
-				TelemetryFieldKey: label.Key,
-				QueryName:         queryName,
-				Type:              qbtypes.ColumnTypeGroup,
-			})
+	// Series can have ragged label sets; build the column schema from the
+	// union of all label keys (first-seen order) and fill rows by key lookup.
+	keyOrder := []telemetrytypes.TelemetryFieldKey{}
+	keyIndex := map[string]int{}
+	for _, series := range tsData.Aggregations[0].Series {
+		for _, label := range series.Labels {
+			if _, ok := keyIndex[label.Key.Name]; ok {
+				continue
+			}
+			keyIndex[label.Key.Name] = len(keyOrder)
+			keyOrder = append(keyOrder, label.Key)
 		}
 	}
 
+	columns := make([]*qbtypes.ColumnDescriptor, 0, len(keyOrder)+len(tsData.Aggregations))
+	for _, key := range keyOrder {
+		columns = append(columns, &qbtypes.ColumnDescriptor{
+			TelemetryFieldKey: key,
+			QueryName:         queryName,
+			Type:              qbtypes.ColumnTypeGroup,
+		})
+	}
+
 	// Add aggregation columns
 	for _, agg := range tsData.Aggregations {
 		name := agg.Alias
@@ -655,18 +665,18 @@ func convertTimeSeriesDataToScalar(tsData *qbtypes.TimeSeriesData, queryName str
 		})
 	}
 
-	// Build rows
+	// Build rows.
+	groupColCount := len(keyOrder)
 	data := [][]any{}
 	for seriesIdx, series := range tsData.Aggregations[0].Series {
 		row := make([]any, len(columns))
 
-		// Add group values
-		for i, label := range series.Labels {
-			row[i] = label.Value
+		// Place each label under its key's column (by lookup, not index).
+		for _, label := range series.Labels {
+			row[keyIndex[label.Key.Name]] = label.Value
 		}
 
 		// Add aggregation values (last value)
-		groupColCount := len(series.Labels)
 		for aggIdx, agg := range tsData.Aggregations {
 			if seriesIdx < len(agg.Series) && len(agg.Series[seriesIdx].Values) > 0 {
 				lastValue := agg.Series[seriesIdx].Values[len(agg.Series[seriesIdx].Values)-1].Value

pkg/querier/postprocess_test.go

@@ -0,0 +1,53 @@
+package querier
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	qbtypes "github.com/SigNoz/signoz/pkg/types/querybuildertypes/querybuildertypesv5"
+	"github.com/SigNoz/signoz/pkg/types/telemetrytypes"
+)
+
+// Multiple series with different number of labels, shouldn't panic and should align labels correctly.
+func TestConvertTimeSeriesDataToScalar_RaggedLabels(t *testing.T) {
+	label := func(name string, value any) *qbtypes.Label {
+		return &qbtypes.Label{
+			Key:   telemetrytypes.TelemetryFieldKey{Name: name},
+			Value: value,
+		}
+	}
+	series := func(labels []*qbtypes.Label, value float64) *qbtypes.TimeSeries {
+		return &qbtypes.TimeSeries{
+			Labels: labels,
+			Values: []*qbtypes.TimeSeriesValue{{Timestamp: 1, Value: value}},
+		}
+	}
+
+	tsData := &qbtypes.TimeSeriesData{
+		QueryName: "A",
+		Aggregations: []*qbtypes.AggregationBucket{{
+			Index: 0,
+			Series: []*qbtypes.TimeSeries{
+				series([]*qbtypes.Label{label("label_1", "orphan-0")}, 20),
+				series([]*qbtypes.Label{label("label_1", "box-0"), label("label_2", "rpc-0")}, 10),
+			},
+		}},
+	}
+
+	var sd *qbtypes.ScalarData
+	require.NotPanics(t, func() {
+		sd = convertTimeSeriesDataToScalar(tsData, "A")
+	})
+
+	require.NotNil(t, sd)
+	require.Len(t, sd.Columns, 3)
+	assert.Equal(t, "label_1", sd.Columns[0].Name)
+	assert.Equal(t, "label_2", sd.Columns[1].Name)
+	assert.Equal(t, "__result_0", sd.Columns[2].Name)
+
+	require.Len(t, sd.Data, 2)
+	assert.Equal(t, []any{"orphan-0", nil, 20.0}, sd.Data[0])
+	assert.Equal(t, []any{"box-0", "rpc-0", 10.0}, sd.Data[1])
+}