changes

lib/gat/gatling/gatling.go

@@ -11,6 +11,7 @@ import (
 	"gfx.cafe/gfx/pggat/lib/gat/admin"
 	"gfx.cafe/gfx/pggat/lib/gat/database"
 	"gfx.cafe/gfx/pggat/lib/gat/gatling/server"
+	"gfx.cafe/gfx/pggat/lib/metrics"
 
 	"gfx.cafe/gfx/pggat/lib/gat"
 	"gfx.cafe/gfx/pggat/lib/gat/gatling/client"
@@ -161,6 +162,7 @@ func (g *Gatling) ListenAndServe(ctx context.Context) error {
 				if err != nil {
 					errch <- err
 				}
+				metrics.RecordAcceptConnectionStatus(err)
 				close(errch)
 				err = g.handleConnection(ctx, c)
 				if err != nil {
@@ -172,6 +174,7 @@ func (g *Gatling) ListenAndServe(ctx context.Context) error {
 
 			err = <-errch
 			if err != nil {
+				// metrics.Counter("pggat", "accept connection errors")
 				log.Println("failed to accept connection:", err)
 			}
 		}
@@ -187,11 +190,13 @@ func (g *Gatling) handleConnection(ctx context.Context, c net.Conn) error {
 		g.mu.Lock()
 		defer g.mu.Unlock()
 		g.clients[cl.GetId()] = cl
+		metrics.RecordActiveConnections(len(g.clients))
 	}()
 	defer func() {
 		g.mu.Lock()
 		defer g.mu.Unlock()
 		delete(g.clients, cl.GetId())
+		metrics.RecordActiveConnections(len(g.clients))
 	}()
 
 	err := cl.Accept(ctx)

lib/metrics/gat.go

+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+type gatMetrics struct {
+	ConnectionCounter      prometheus.Counter
+	ConnectionErrorCounter *prometheus.CounterVec
+	ActiveConnections      prometheus.Gauge
+}
+
+func GatMetrics() *gatMetrics {
+	s.Lock()
+	defer s.Unlock()
+	if s.gat == nil {
+		s.gat = newGatmetrics()
+	}
+	return s.gat
+}
+
+func newGatmetrics() *gatMetrics {
+	o := &gatMetrics{
+		ConnectionCounter: promauto.NewCounter(prometheus.CounterOpts{
+			Name: "pggat_connection_count_total",
+			Help: "total number of connections initiated with pggat",
+		}),
+		ConnectionErrorCounter: promauto.NewCounterVec(prometheus.CounterOpts{
+			Name: "pggat_connection_error_count_total",
+			Help: "total number of connections initiated with pggat",
+		}, []string{"error"}),
+		ActiveConnections: promauto.NewGauge(prometheus.GaugeOpts{
+			Name: "pggat_current_connection_count",
+			Help: "number of connections to pggat currently",
+		}),
+	}
+	return o
+}
+
+func RecordAcceptConnectionStatus(err error) {
+	if !On() {
+		return
+	}
+	g := GatMetrics()
+	if err != nil {
+		g.ConnectionErrorCounter.WithLabelValues(err.Error()).Inc()
+	}
+	g.ConnectionCounter.Inc()
+}
+
+func RecordActiveConnections(count int) {
+	if !On() {
+		return
+	}
+	g := GatMetrics()
+	g.ActiveConnections.Set(float64(count))
+}

lib/metrics/metrics.go

@@ -22,6 +22,7 @@ type metrics struct {
 	counters map[string]prometheus.Counter
 	histos   map[string]prometheus.Histogram
 	pools    map[string]poolMetrics
+	gat      *gatMetrics
 	sync.RWMutex
 }