app/vmstorage: properly handle maxSeries limit passed from vmselect to vmstorage

app/vmstorage/transport/server.go

@@ -1143,12 +1143,12 @@ var (
 
 func (ctx *vmselectRequestCtx) getMaxMetrics() int {
 	maxMetrics := ctx.sq.MaxMetrics
-	if maxMetrics <= 0 || maxMetrics > *maxMetricsPerSearch {
-		maxMetrics = *maxMetricsPerSearch
+	maxMetricsLimit := *maxMetricsPerSearch
+	if maxMetricsLimit <= 0 {
+		maxMetricsLimit = 2e9
 	}
-	if maxMetrics <= 0 {
-		// The limit is missing.
-		maxMetrics = 2e9
+	if maxMetrics <= 0 || maxMetrics > maxMetricsLimit {
+		maxMetrics = maxMetricsLimit
 	}
 	return maxMetrics
 }

docs/CHANGELOG.md

@@ -17,6 +17,7 @@ The following tip changes can be tested by building VictoriaMetrics components f
 
 FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert.html): add support for `alert_relabel_configs` option at `-notifier.config`. This option allows configuring relabeling rules for alerts before sending them to configured notifiers. See [these docs](https://docs.victoriametrics.com/vmalert.html#notifier-configuration-file) for details.
 
+BUGFIX: properly propagate limits at `-search.max*` command-line flags from `vminsert` to `vmstorage`. The limits are `-search.maxUniqueTimeseries`, `-search.maxSeries`, `-search.maxFederateSeries`, `-search.maxExportSeries`, `-search.maxGraphiteSeries` and `-search.maxTSDBStatusSeries`. They weren't propagated to `vmstorage` because of the bug. These limits were introduced in [v1.76.0](https://docs.victoriametrics.com/CHANGELOG.html#v1760).
 BUGFIX: fix goroutine leak and possible deadlock when importing invalid data via [native binary format](https://docs.victoriametrics.com/#how-to-import-data-in-native-format). See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/2423).
 BUGFIX: [Graphite Render API](https://docs.victoriametrics.com/#graphite-render-api-usage): properly calculate [hitCount](https://graphite.readthedocs.io/en/latest/functions.html#graphite.render.functions.hitcount) function. Previously it could return empty results if there were no original samples in some parts of the selected time range.
 BUGFIX: [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html): allow overriding built-in function names inside [WITH templates](https://play.victoriametrics.com/promql/expand-with-exprs). For example, `WITH (sum(a,b) = a + b + 1) sum(x,y)` now expands into `x + y + 1`. Previously such a query would fail with `cannot use reserved name` error. See [this bugreport](https://github.com/VictoriaMetrics/metricsql/issues/5).

lib/storage/index_db.go

@@ -2252,7 +2252,8 @@ func (is *indexSearch) searchMetricIDsInternal(tfss []*TagFilters, tr TimeRange,
 			return nil, err
 		}
 		if metricIDs.Len() > maxMetrics {
-			return nil, fmt.Errorf("the number of matching unique timeseries exceeds %d; either narrow down the search or increase -search.maxUniqueTimeseries", maxMetrics)
+			return nil, fmt.Errorf("the number of matching timeseries exceeds %d; either narrow down the search "+
+				"or increase -search.max* command-line flag values at vmselect", maxMetrics)
 		}
 	}
 	return metricIDs, nil
@@ -2272,6 +2273,10 @@ func (is *indexSearch) updateMetricIDsForTagFilters(metricIDs *uint64set.Set, tf
 	atomic.AddUint64(&is.db.globalSearchCalls, 1)
 	m, err := is.getMetricIDsForDateAndFilters(0, tfs, maxMetrics)
 	if err != nil {
+		if errors.Is(err, errFallbackToGlobalSearch) {
+			return fmt.Errorf("the number of matching timeseries exceeds %d; either narrow down the search "+
+				"or increase -search.max* command-line flag values at vmselect", maxMetrics)
+		}
 		return err
 	}
 	metricIDs.UnionMayOwn(m)