Report fabric peer session telemetry

agents/rap-node-agent/internal/mesh/fabric_session_manager.go

@@ -10,6 +10,7 @@ import (
 type FabricSessionPeerManager struct {
 	mu       sync.Mutex
 	sessions map[string]*FabricSessionPump
+	stats    FabricSessionPeerManagerStats
 }
 
 type FabricSessionPeerTarget struct {
@@ -19,6 +20,21 @@ type FabricSessionPeerTarget struct {
 	Pump    FabricSessionPumpOptions
 }
 
+type FabricSessionPeerManagerStats struct {
+	Opens          uint64 `json:"opens"`
+	Reuses         uint64 `json:"reuses"`
+	ClosedEvicted  uint64 `json:"closed_evicted"`
+	ClosePeerCalls uint64 `json:"close_peer_calls"`
+	CloseAllCalls  uint64 `json:"close_all_calls"`
+}
+
+type FabricSessionPeerManagerSnapshot struct {
+	SchemaVersion string                        `json:"schema_version"`
+	ActiveCount   int                           `json:"active_count"`
+	ClosedCount   int                           `json:"closed_count"`
+	Stats         FabricSessionPeerManagerStats `json:"stats"`
+}
+
 func NewFabricSessionPeerManager() *FabricSessionPeerManager {
 	return &FabricSessionPeerManager{
 		sessions: map[string]*FabricSessionPump{},
@@ -37,7 +53,9 @@ func (m *FabricSessionPeerManager) Get(ctx context.Context, target FabricSession
 	if pump := m.sessions[key]; pump != nil {
 		if pump.Closed() {
 			delete(m.sessions, key)
+			m.stats.ClosedEvicted++
 		} else {
+			m.stats.Reuses++
 			m.mu.Unlock()
 			return pump, nil
 		}
@@ -54,7 +72,9 @@ func (m *FabricSessionPeerManager) Get(ctx context.Context, target FabricSession
 	if existing := m.sessions[key]; existing != nil {
 		if existing.Closed() {
 			delete(m.sessions, key)
+			m.stats.ClosedEvicted++
 		} else {
+			m.stats.Reuses++
 			m.mu.Unlock()
 			_ = pump.Close()
 			return existing, nil
@@ -64,6 +84,7 @@ func (m *FabricSessionPeerManager) Get(ctx context.Context, target FabricSession
 		m.sessions = map[string]*FabricSessionPump{}
 	}
 	m.sessions[key] = pump
+	m.stats.Opens++
 	m.mu.Unlock()
 	return pump, nil
 }
@@ -77,6 +98,7 @@ func (m *FabricSessionPeerManager) ClosePeer(target FabricSessionPeerTarget) err
 		return err
 	}
 	m.mu.Lock()
+	m.stats.ClosePeerCalls++
 	pump := m.sessions[key]
 	delete(m.sessions, key)
 	m.mu.Unlock()
@@ -91,6 +113,7 @@ func (m *FabricSessionPeerManager) Close() error {
 		return nil
 	}
 	m.mu.Lock()
+	m.stats.CloseAllCalls++
 	sessions := m.sessions
 	m.sessions = map[string]*FabricSessionPump{}
 	m.mu.Unlock()
@@ -103,6 +126,26 @@ func (m *FabricSessionPeerManager) Close() error {
 	return firstErr
 }
 
+func (m *FabricSessionPeerManager) Snapshot() FabricSessionPeerManagerSnapshot {
+	if m == nil {
+		return FabricSessionPeerManagerSnapshot{SchemaVersion: "rap.fabric_session_peer_manager.v1"}
+	}
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	snapshot := FabricSessionPeerManagerSnapshot{
+		SchemaVersion: "rap.fabric_session_peer_manager.v1",
+		Stats:         m.stats,
+	}
+	for _, pump := range m.sessions {
+		if pump == nil || pump.Closed() {
+			snapshot.ClosedCount++
+			continue
+		}
+		snapshot.ActiveCount++
+	}
+	return snapshot
+}
+
 func fabricSessionPeerKey(target FabricSessionPeerTarget) (string, error) {
 	peerID := strings.TrimSpace(target.PeerID)
 	baseURL := strings.TrimRight(strings.TrimSpace(target.BaseURL), "/")