improve session storage to support multiple sessions from single visitor

pkg/handlers/events_custom.go

@@ -71,7 +71,7 @@ func eventsCustomHandler(
 	)
 
 	var ok bool
-	customEv.Session, ok = sessionStorage.WaitSession(deviceId, hutils.ContextTimeout(ctx))
+	customEv.Session, ok = sessionStorage.WaitSession(deviceId, customEv.PageUri, hutils.ContextTimeout(ctx))
 	// Session not found.
 	if !ok {
 		return errSessionNotFound

pkg/handlers/events_pageviews.go

@@ -85,6 +85,27 @@ func eventsPageviewsHandler(
 		ipAddr, utils.UnsafeBytes(pageView.PageUri.Host()),
 	)
 
+	// Special case, referrer URI is the same as page URI.
+	// This happens when user refresh page or a tab is duplicated.
+	// In both cases we want to insert a new session in temporary storage (memory)
+	// but we don't want to send it to the persisten store (eventstore). This new
+	// duplicated session will be persisted on next page view. This way we're sure
+	// that duplicated session is used.
+	if (referrerUri.IsValid() && pageView.PageUri.IsValid() && referrerUri.Host() == pageView.PageUri.Host() &&
+		referrerUri.Path() == pageView.PageUri.Path()) || !referrerUri.IsValid() {
+		session, found := sessionStorage.WaitSession(deviceId, pageView.PageUri, time.Duration(0))
+		if found {
+			session.SessionUuid, err = uuid.NewV7()
+			if err != nil {
+				return fmt.Errorf("failed to generate session uuid: %w", err)
+			}
+			sessionStorage.InsertSession(deviceId, session)
+
+			// Early return as we don't send event to the eventstore.
+			return nil
+		}
+	}
+
 	isInternalTraffic := referrerUri.IsValid() && referrerUri.Host() == pageView.PageUri.Host()
 	newSession := !isInternalTraffic
 
@@ -93,18 +114,18 @@ func eventsPageviewsHandler(
 		sessionExists := false
 		if visitorId != "" { // Identify session.
 			visitorId = utils.CopyString(visitorId)
-			_, sessionExists = sessionStorage.IdentifySession(deviceId, visitorId)
+			_, sessionExists = sessionStorage.IdentifySession(deviceId, pageView.PageUri, visitorId)
 			if sessionExists {
 
 				// Increment pageview count.
-				pageView.Session, sessionExists = sessionStorage.IncSessionPageviewCount(deviceId)
+				pageView.Session, sessionExists = sessionStorage.AddPageview(deviceId, referrerUri, pageView.PageUri)
 				if !sessionExists { // Should never happend.
 					logger.Panic().Msg("failed to increment session pageview count after IdentifySession returned a session")
 				}
 			}
 		} else { // Anon session.
 			// Increment pageview count.
-			pageView.Session, sessionExists = sessionStorage.IncSessionPageviewCount(deviceId)
+			pageView.Session, sessionExists = sessionStorage.AddPageview(deviceId, referrerUri, pageView.PageUri)
 		}
 
 		if !sessionExists {

pkg/services/sessionstorage/metrics.go

@@ -7,7 +7,6 @@ type metrics struct {
 	sessionsWait      prometheus.Gauge
 	sessionsCounter   *prometheus.CounterVec
 	sessionsPageviews prometheus.Histogram
-	getSessionsMiss   prometheus.Counter
 }
 
 func newMetrics(promRegistry *prometheus.Registry) metrics {
@@ -29,18 +28,13 @@ func newMetrics(promRegistry *prometheus.Registry) metrics {
 			Help:    "Number of pageviews per sessions",
 			Buckets: []float64{1, 2, 3, 5, 10, 15, 25, 30, 50, 100},
 		}),
-		getSessionsMiss: prometheus.NewCounter(prometheus.CounterOpts{
-			Name: "sessionstorage_get_session_misses",
-			Help: "Number of get sessions call that wasn't found",
-		}),
 	}
 
 	promRegistry.MustRegister(
 		m.activeSessions,
 		m.sessionsWait,
 		m.sessionsCounter,
 		m.sessionsPageviews,
-		m.getSessionsMiss,
 	)
 
 	return m