From 8a67dd1b9f40ee089b3193ef3dc0967189a26548 Mon Sep 17 00:00:00 2001
From: Raja Subramanian <raja.gobi@tutanota.com>
Date: Fri, 3 Apr 2026 21:50:59 +0530
Subject: [PATCH] Do not close publisher peer connection to aid migration.
 (#4427)

---
 pkg/rtc/participant.go               |  4 +--
 pkg/rtc/signalling/signallerasync.go | 44 ++++++++++++++++------------
 pkg/rtc/transportmanager.go          |  4 +++
 pkg/service/rtcservice.go            |  3 +-
 4 files changed, 33 insertions(+), 22 deletions(-)

diff --git a/pkg/rtc/participant.go b/pkg/rtc/participant.go
index 4efd90f23..62f579677 100644
--- a/pkg/rtc/participant.go
+++ b/pkg/rtc/participant.go
@@ -1513,7 +1513,7 @@ func (p *ParticipantImpl) setupMigrationTimerLocked() {
 		if p.IsClosed() || p.IsDisconnected() {
 			return
 		}
-		p.subLogger.Debugw("closing peer connection(s) to aid migration")
+		p.subLogger.Debugw("closing subscriber peer connection to aid migration")
 
 		//
 		// Close all down tracks before closing subscriber peer connection.
@@ -1523,7 +1523,7 @@ func (p *ParticipantImpl) setupMigrationTimerLocked() {
 		//
 		p.SubscriptionManager.Close(true)
 
-		p.TransportManager.Close()
+		p.TransportManager.SubscriberClose()
 	})
 }
 
diff --git a/pkg/rtc/signalling/signallerasync.go b/pkg/rtc/signalling/signallerasync.go
index 15fb5814e..a25486faa 100644
--- a/pkg/rtc/signalling/signallerasync.go
+++ b/pkg/rtc/signalling/signallerasync.go
@@ -53,7 +53,19 @@ func (s *signallerAsync) WriteMessage(msg proto.Message) error {
 		return nil
 	}
 
+	getMessageType := func(msg proto.Message) string {
+		messageType := "unknown"
+		if typed, ok := msg.(*livekit.SignalResponse); ok {
+			messageType = fmt.Sprintf("%T", typed.Message)
+		}
+		return messageType
+	}
+
 	if s.params.Participant.IsDisconnected() {
+		s.params.Logger.Debugw(
+			"counld not send message to participant, participant disconnected",
+			"messageType", getMessageType(msg),
+		)
 		return nil
 	}
 
@@ -72,33 +84,27 @@ func (s *signallerAsync) WriteMessage(msg proto.Message) error {
 
 	sink := s.GetResponseSink()
 	if sink == nil {
-		if typed, ok := msg.(*livekit.SignalResponse); ok {
-			s.params.Logger.Debugw(
-				"could not send message to participant",
-				"messageType", fmt.Sprintf("%T", typed.Message),
-			)
-		}
+		s.params.Logger.Debugw(
+			"could not send message to participant, no sink",
+			"messageType", getMessageType(msg),
+		)
 		return nil
 	}
 
 	err := sink.WriteMessage(msg)
 	if err != nil {
 		if utils.ErrorIsOneOf(err, psrpc.Canceled, routing.ErrChannelClosed) {
-			if typed, ok := msg.(*livekit.SignalResponse); ok {
-				s.params.Logger.Debugw(
-					"could not send message to participant",
-					"error", err,
-					"messageType", fmt.Sprintf("%T", typed.Message),
-				)
-			}
+			s.params.Logger.Debugw(
+				"could not send message to participant",
+				"error", err,
+				"messageType", getMessageType(msg),
+			)
 			return nil
 		} else {
-			if typed, ok := msg.(*livekit.SignalResponse); ok {
-				s.params.Logger.Warnw(
-					"could not send message to participant", err,
-					"messageType", fmt.Sprintf("%T", typed.Message),
-				)
-			}
+			s.params.Logger.Warnw(
+				"could not send message to participant", err,
+				"messageType", getMessageType(msg),
+			)
 			return err
 		}
 	} else {
diff --git a/pkg/rtc/transportmanager.go b/pkg/rtc/transportmanager.go
index 80e5fac87..25cacf8fe 100644
--- a/pkg/rtc/transportmanager.go
+++ b/pkg/rtc/transportmanager.go
@@ -211,6 +211,10 @@ func (t *TransportManager) Close() {
 	}
 }
 
+func (t *TransportManager) SubscriberClose() {
+	t.subscriber.Close()
+}
+
 func (t *TransportManager) HasPublisherEverConnected() bool {
 	return t.publisher.HasEverConnected()
 }
diff --git a/pkg/service/rtcservice.go b/pkg/service/rtcservice.go
index e96901dbd..e8c225518 100644
--- a/pkg/service/rtcservice.go
+++ b/pkg/service/rtcservice.go
@@ -335,7 +335,7 @@ func (s *RTCService) serve(w http.ResponseWriter, r *http.Request, needsJoinRequ
 
 	roomName, pi, code, err = s.validateInternal(pLogger, r, needsJoinRequest, false)
 	if err != nil {
-		HandleError(w, r, code, err)
+		HandleError(w, r, code, err, getLoggerFields()...)
 		return
 	}
 
@@ -343,6 +343,7 @@ func (s *RTCService) serve(w http.ResponseWriter, r *http.Request, needsJoinRequ
 	if pi.ID != "" {
 		pID = pi.ID
 	}
+	pLogger.Debugw("join request validated", append(getLoggerFields(), "participantInit", &pi))
 
 	// give it a few attempts to start session
 	var cr connectionResult