Report VPN fabric stream cleanup

agents/rap-node-agent/internal/vpnruntime/fabric_session_transport.go

@@ -46,6 +46,8 @@ type FabricSessionPacketTransport struct {
 	sendFramesByClass  map[string]uint64
 	sendPacketsByClass map[string]uint64
 	sendFramesByStream map[uint64]uint64
+	closeStreamFrames  uint64
+	closeErrors        uint64
 	closeOnce          sync.Once
 	closeErr           error
 }
@@ -184,14 +186,22 @@ func (t *FabricSessionPacketTransport) Close() error {
 				if err := t.Sender.Send(ctx, fabricproto.Frame{
 					Type:     fabricproto.FrameCloseStream,
 					StreamID: streamID,
-				}); err != nil && t.closeErr == nil {
-					t.closeErr = err
+				}); err != nil {
+					t.recordCloseError()
+					if t.closeErr == nil {
+						t.closeErr = err
+					}
+				} else if err == nil {
+					t.recordCloseStream()
 				}
 			}
 		}
 		if closer, ok := t.Sender.(FabricSessionCloser); ok {
-			if err := closer.Close(); err != nil && t.closeErr == nil {
-				t.closeErr = err
+			if err := closer.Close(); err != nil {
+				t.recordCloseError()
+				if t.closeErr == nil {
+					t.closeErr = err
+				}
 			}
 		}
 	})
@@ -336,6 +346,8 @@ func (t *FabricSessionPacketTransport) Snapshot() map[string]any {
 	t.statsMu.Lock()
 	sendFramesByClass := copyStringUint64Map(t.sendFramesByClass)
 	sendPacketsByClass := copyStringUint64Map(t.sendPacketsByClass)
+	closeStreamFrames := t.closeStreamFrames
+	closeErrors := t.closeErrors
 	sendFramesByStream := make(map[string]uint64, len(t.sendFramesByStream))
 	for streamID, count := range t.sendFramesByStream {
 		sendFramesByStream[fmt.Sprintf("%d", streamID)] = count
@@ -351,12 +363,32 @@ func (t *FabricSessionPacketTransport) Snapshot() map[string]any {
 		"send_class_count":         countNonZeroStringUint64Values(sendFramesByClass),
 		"send_stream_count":        countNonZeroStringUint64Values(sendFramesByStream),
 		"sharding_active":          len(streamIDsByClass) > 1 || countStreamIDs(streamIDsByClass)+len(t.StreamIDs) > 1,
+		"close_stream_frames":      closeStreamFrames,
+		"close_errors":             closeErrors,
 		"send_frames_by_class":     sendFramesByClass,
 		"send_packets_by_class":    sendPacketsByClass,
 		"send_frames_by_stream_id": sendFramesByStream,
 	}
 }
 
+func (t *FabricSessionPacketTransport) recordCloseStream() {
+	if t == nil {
+		return
+	}
+	t.statsMu.Lock()
+	t.closeStreamFrames++
+	t.statsMu.Unlock()
+}
+
+func (t *FabricSessionPacketTransport) recordCloseError() {
+	if t == nil {
+		return
+	}
+	t.statsMu.Lock()
+	t.closeErrors++
+	t.statsMu.Unlock()
+}
+
 func fabricSessionTrafficClassForPackets(fallback string, packets [][]byte) string {
 	if fallback = normalizeFabricTrafficClass(fallback); fallback != "" && fallback != FabricTrafficClassBulk {
 		return fallback