SigNoz/signoz · error · model.InternalError

couldn't query clickhouse for received metrics status: %w

Error message

couldn't query clickhouse for received metrics status: %w

What it means

Internal error wrapping a ClickHouse query failure while fetching the latest-received status of a metric (last received timestamp and labels) from the time_series table. The %w wrapping preserves the underlying ClickHouse error for diagnosis.

Source

Thrown at pkg/query-service/app/clickhouseReader/reader.go:3404

		group by metric_name
		limit 1
		`, signozMetricDBName, signozTSTableNameV4, whereClause,
			signozMetricDBName, signozTSTableNameV4Reduced, whereClause,
		)
	} else {
		query = fmt.Sprintf(`
		SELECT metric_name, anyLast(labels), max(unix_milli)
		from %s.%s
		where %s
		group by metric_name
		limit 1
		`, signozMetricDBName, signozTSTableNameV4, whereClause,
		)
	}

	rows, err := r.db.Query(ctx, query)
	if err != nil {
		return nil, model.InternalError(fmt.Errorf(
			"couldn't query clickhouse for received metrics status: %w", err,
		))
	}
	defer rows.Close()

	var result *model.MetricStatus

	if rows.Next() {

		result = &model.MetricStatus{}
		var labelsJson string

		err := rows.Scan(
			&result.MetricName,
			&labelsJson,
			&result.LastReceivedTsMillis,
		)
		if err != nil {

View on GitHub (pinned to 5069bf80b0)

Solutions

Read the wrapped ClickHouse error to classify cause
Test the same query manually in clickhouse-client with the quoted metric names
Verify signoz_metrics.time_series exists and query-service version matches schema
Check ClickHouse health and query-service connection pool metrics

Defensive patterns

Strategy: retry

Validate before calling

// Verify table exists before heavy calls
if !chTableExists(ctx, db, "signoz_metrics", "time_series") {
    return errors.New("time_series table missing; run migrations")
}

Try / catch

if err != nil {
    var ich *chError
    if errors.As(err, &ich) && ich.Transient() { retry(ctx, call) }
}

Prevention

Quote metric names with ClickHouseFormattedValue
Health-check ClickHouse before batch operations

When it happens

Trigger: GetLatestReceivedMetric successfully validated names but the status query failed — bad quoted metric name interpolation, missing time_series table, timeout, or connection failure.

Common situations: Metric names with special characters breaking utils.ClickHouseFormattedValue quoting; ClickHouse unavailable; schema migration pending after SigNoz upgrade.

Related errors

AI-assisted analysis of SigNoz/signoz@5069bf80b0 (2026-08-28). Data as JSON: /api/errors/49b4e0bb7b9dc6ec. Report an issue: GitHub.