Added metrics for sus/malicious connections

internal/server/metrics/metrics.go

@@ -26,6 +26,12 @@ var RequestProcessingDuration = promauto.NewHistogramVec(prometheus.HistogramOpt
 	NativeHistogramBucketFactor: 1.00271,
 }, []string{"request_type", "dropped"})
 
+var ConnectionsRateLimited = promauto.NewCounterVec(prometheus.CounterOpts{
+	Namespace: namespace,
+	Name:      "connections_rate_limited_total",
+	Help:      "The total number of rate limited connections",
+}, []string{"category"})
+
 var ConnectionsEstablished = promauto.NewCounter(prometheus.CounterOpts{
 	Namespace: namespace,
 	Name:      "connections_established_total",

internal/server/server.go

@@ -636,6 +636,7 @@ func (s *server) isRateLimited(ip uint32) bool {
 			s.ipConns[ip] = entry
 			return false
 		} else if entry.count < RateLimitCountThresholdMalicious {
+			metrics.ConnectionsRateLimited.WithLabelValues("suspicious").Inc()
 			if entry.count == RateLimitCountThresholdSus {
 				slog.Warn("suspicious connection activity", "ip", ipStr, "count", entry.count)
 				// Only log the first one
@@ -644,6 +645,7 @@ func (s *server) isRateLimited(ip uint32) bool {
 			s.ipConns[ip] = entry
 			return true
 		} else {
+			metrics.ConnectionsRateLimited.WithLabelValues("malicious").Inc()
 			if entry.count == RateLimitCountThresholdMalicious {
 				slog.Warn("potential malicious connection behavior", "ip", ipStr, "count", entry.count)
 				// Only log the first one