Fix resource overflow issue with defer.

Author: clems4ever

internal/server/monitoring.go

@@ -22,51 +22,55 @@ func getMonitoringIntervalSeconds() time.Duration {
 
 // startGraphSizeMonitoring start a background process regularly checking the size of the graph to expose it as a prometheus metric
 func startGraphSizeMonitoring(interval time.Duration, database knowledge.GraphDB, sourcesRegistry sources.Registry) {
-	logrus.Infof("Monitoring of the graph size will happen every %ds", int(interval/time.Second))
-	go func() {
-		for {
-			ctx, cancel := context.WithTimeout(context.Background(), interval)
-			defer cancel()
+	monitorForOneIteration := func() {
+		ctx, cancel := context.WithTimeout(context.Background(), interval)
+		defer cancel()
 
-			logrus.Debug("Start monitoring the graph size...")
-			assetsCount, err := database.CountAssets(ctx)
-			if err != nil {
-				metrics.GraphAssetsAggregatedGauge.Set(-1)
-			} else {
-				metrics.GraphAssetsAggregatedGauge.Set(float64(assetsCount))
-			}
+		logrus.Debug("Start monitoring the graph size...")
+		assetsCount, err := database.CountAssets(ctx)
+		if err != nil {
+			metrics.GraphAssetsAggregatedGauge.Set(-1)
+		} else {
+			metrics.GraphAssetsAggregatedGauge.Set(float64(assetsCount))
+		}
+
+		relationsCount, err := database.CountRelations(ctx)
+		if err != nil {
+			metrics.GraphRelationsAggregatedGauge.Set(-1)
+		} else {
+			metrics.GraphRelationsAggregatedGauge.Set(float64(relationsCount))
+		}
+
+		sources, err := sourcesRegistry.ListSources(ctx)
+		if err != nil {
+			logrus.Errorf("Unable to list sources for monitoring: %v", err)
+			metrics.GraphAssetsTotalGauge.Reset()
+			metrics.GraphRelationsTotalGauge.Reset()
+		}
 
-			relationsCount, err := database.CountRelations(ctx)
+		for s := range sources {
+			assetsCount, err := database.CountAssetsBySource(ctx, s)
 			if err != nil {
-				metrics.GraphRelationsAggregatedGauge.Set(-1)
+				logrus.Errorf("Unable to count assets of source %s for monitoring: %w", s, err)
+				metrics.GraphAssetsTotalGauge.Reset()
 			} else {
-				metrics.GraphRelationsAggregatedGauge.Set(float64(relationsCount))
+				metrics.GraphAssetsTotalGauge.With(prometheus.Labels{"source": s}).Set(float64(assetsCount))
 			}
 
-			sources, err := sourcesRegistry.ListSources(ctx)
+			relationsCount, err := database.CountRelationsBySource(ctx, s)
 			if err != nil {
-				logrus.Errorf("Unable to list sources for monitoring: %v", err)
-				metrics.GraphAssetsTotalGauge.Reset()
+				logrus.Errorf("Unable to count relations of source %s for monitoring: %w", s, err)
 				metrics.GraphRelationsTotalGauge.Reset()
+			} else {
+				metrics.GraphRelationsTotalGauge.With(prometheus.Labels{"source": s}).Set(float64(relationsCount))
 			}
+		}
+	}
 
-			for s := range sources {
-				assetsCount, err := database.CountAssetsBySource(ctx, s)
-				if err != nil {
-					logrus.Errorf("Unable to count assets of source %s for monitoring: %w", s, err)
-					metrics.GraphAssetsTotalGauge.Reset()
-				} else {
-					metrics.GraphAssetsTotalGauge.With(prometheus.Labels{"source": s}).Set(float64(assetsCount))
-				}
-
-				relationsCount, err := database.CountRelationsBySource(ctx, s)
-				if err != nil {
-					logrus.Errorf("Unable to count relations of source %s for monitoring: %w", s, err)
-					metrics.GraphRelationsTotalGauge.Reset()
-				} else {
-					metrics.GraphRelationsTotalGauge.With(prometheus.Labels{"source": s}).Set(float64(relationsCount))
-				}
-			}
+	logrus.Infof("Monitoring of the graph size will happen every %ds", int(interval/time.Second))
+	go func() {
+		for {
+			monitorForOneIteration()
 			time.Sleep(interval)
 		}
 	}()