feat(metrics): add proxy rejected max connections metric (#4589)

This change adds the `osm_proxy_max_connections_rejected` metric which counts the number of proxy connections rejected because of the limit defined by the MeshConfig's spec.sidecar.maxDataPlaneConnections having been reached. Part of #4568 Signed-off-by: Jon Huhn <[email protected]>
openservicemesh · Mar 11, 2022 · 1775316 · 1775316
1 parent b7a4a3b
commit 1775316
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diff --git a/cmd/osm-controller/osm-controller.go b/cmd/osm-controller/osm-controller.go
@@ -307,6 +307,7 @@ func startMetricsStore() {
 		metricsstore.DefaultMetricsStore.HTTPResponseDuration,
 		metricsstore.DefaultMetricsStore.FeatureFlagEnabled,
 		metricsstore.DefaultMetricsStore.ProxyXDSRequestCount,
+		metricsstore.DefaultMetricsStore.ProxyMaxConnectionsRejected,
 	)
 }
 

diff --git a/pkg/envoy/ads/stream.go b/pkg/envoy/ads/stream.go
@@ -34,6 +34,7 @@ func (s *Server) StreamAggregatedResources(server xds_discovery.AggregatedDiscov
 
 	// If maxDataPlaneConnections is enabled i.e. not 0, then check that the number of Envoy connections is less than maxDataPlaneConnections
 	if s.cfg.GetMaxDataPlaneConnections() != 0 && s.proxyRegistry.GetConnectedProxyCount() >= s.cfg.GetMaxDataPlaneConnections() {
+		metricsstore.DefaultMetricsStore.ProxyMaxConnectionsRejected.Inc()
 		return errTooManyConnections
 	}
 

diff --git a/pkg/metricsstore/metricsstore.go b/pkg/metricsstore/metricsstore.go
@@ -52,6 +52,10 @@ type MetricsStore struct {
 	// ProxyXDSRequestCount counts XDS requests made by proxies
 	ProxyXDSRequestCount *prometheus.CounterVec
 
+	// ProxyMaxConnectionsRejected counts the number of proxy connections
+	// rejected due to the max connections limit being reached
+	ProxyMaxConnectionsRejected prometheus.Counter
+
 	/*
 	 * Injector metrics
 	 */
@@ -181,6 +185,13 @@ func init() {
 		Help:      "Represents the number of XDS requests made by proxies",
 	}, []string{"common_name", "type"})
 
+	defaultMetricsStore.ProxyMaxConnectionsRejected = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: metricsRootNamespace,
+		Subsystem: "proxy",
+		Name:      "max_connections_rejected",
+		Help:      "Represents the number of proxy connections rejected due to the configured max connections limit",
+	})
+
 	/*
 	 * Injector metrics
 	 */