fix(network): do not log connection error for established connections

sn_networking/src/driver.rs

@@ -32,7 +32,6 @@ use futures::future::Either;
 use futures::StreamExt;
 #[cfg(feature = "local")]
 use libp2p::mdns;
-use libp2p::Transport as _;
 use libp2p::{core::muxing::StreamMuxerBox, relay};
 use libp2p::{
     identity::Keypair,
@@ -45,6 +44,7 @@ use libp2p::{
     },
     Multiaddr, PeerId,
 };
+use libp2p::{swarm::SwarmEvent, Transport as _};
 #[cfg(feature = "open-metrics")]
 use prometheus_client::metrics::info::Info;
 use sn_evm::PaymentQuote;
@@ -721,6 +721,7 @@ impl NetworkBuilder {
             network_discovery: NetworkDiscovery::new(&peer_id),
             bootstrap_peers: Default::default(),
             live_connected_peers: Default::default(),
+            latest_connected_peers: Default::default(),
             handling_statistics: Default::default(),
             handled_times: 0,
             hard_disk_write_error: 0,
@@ -819,6 +820,10 @@ pub struct SwarmDriver {
     // Peers that having live connection to. Any peer got contacted during kad network query
     // will have live connection established. And they may not appear in the RT.
     pub(crate) live_connected_peers: BTreeMap<ConnectionId, (PeerId, Instant)>,
+    /// The peers that we connected to recently to.
+    /// This is a limited list used to prevent log spamming.
+    /// Use `live_connected_peers` for a full list.
+    pub(crate) latest_connected_peers: HashMap<Multiaddr, Instant>,
     // Record the handling time of the recent 10 for each handling kind.
     handling_statistics: BTreeMap<String, Vec<Duration>>,
     handled_times: usize,
@@ -846,6 +851,8 @@ impl SwarmDriver {
         let mut set_farthest_record_interval = interval(CLOSET_RECORD_CHECK_INTERVAL);
         let mut relay_manager_reservation_interval = interval(RELAY_MANAGER_RESERVATION_INTERVAL);
 
+        // temporarily skip processing IncomingConnectionError swarm event to avoid log spamming
+        let mut previous_incoming_connection_error_event = None;
         loop {
             tokio::select! {
                 // polls futures in order they appear here (as opposed to random)
@@ -878,6 +885,19 @@ impl SwarmDriver {
                 },
                 // next take and react to external swarm events
                 swarm_event = self.swarm.select_next_some() => {
+
+                    // Refer to the handle_swarm_events::IncomingConnectionError for more info on why we skip
+                    // processing the event for one round.
+                    if let Some(previous_event) = previous_incoming_connection_error_event.take() {
+                        if let Err(err) = self.handle_swarm_events(previous_event) {
+                            warn!("Error while handling swarm event: {err}");
+                        }
+                    }
+                    if matches!(swarm_event, SwarmEvent::IncomingConnectionError {..}) {
+                        previous_incoming_connection_error_event = Some(swarm_event);
+                        continue;
+                    }
+
                     // logging for handling events happens inside handle_swarm_events
                     // otherwise we're rewriting match statements etc around this anwyay
                     if let Err(err) = self.handle_swarm_events(swarm_event) {

sn_networking/src/event/swarm.rs

@@ -364,6 +364,7 @@ impl SwarmDriver {
                     connection_id,
                     (peer_id, Instant::now() + Duration::from_secs(60)),
                 );
+                self.insert_latest_connected_peers(endpoint.get_remote_address().clone());
                 self.record_connection_metrics();
 
                 if endpoint.is_dialer() {
@@ -380,6 +381,9 @@ impl SwarmDriver {
                 event_string = "ConnectionClosed";
                 debug!(%peer_id, ?connection_id, ?cause, num_established, "ConnectionClosed: {}", endpoint_str(&endpoint));
                 let _ = self.live_connected_peers.remove(&connection_id);
+                let _ = self
+                    .latest_connected_peers
+                    .remove(endpoint.get_remote_address());
                 self.record_connection_metrics();
             }
             SwarmEvent::OutgoingConnectionError {
@@ -509,7 +513,18 @@ impl SwarmDriver {
                 error,
             } => {
                 event_string = "Incoming ConnErr";
-                error!("IncomingConnectionError from local_addr:?{local_addr:?}, send_back_addr {send_back_addr:?} on {connection_id:?} with error {error:?}");
+                // Only log if this for a non-existing connection.
+                // If a peer contains multiple transports/listen addrs, we might try to open multiple connections,
+                // and if the first one passes, we would get error on the rest. We don't want to log these.
+                //
+                // Also sometimes we get the ConnectionEstablished event immediately after this event.
+                // So during tokio::select! of the events, we skip processing IncomingConnectionError for one round,
+                // giving time for ConnectionEstablished to be hopefully processed.
+                // And since we don't do anything critical with this event, the order and time of processing is
+                // not critical.
+                if !self.latest_connected_peers.contains_key(&send_back_addr) {
+                    error!("IncomingConnectionError from local_addr:?{local_addr:?}, send_back_addr {send_back_addr:?} on {connection_id:?} with error {error:?}");
+                }
                 let _ = self.live_connected_peers.remove(&connection_id);
                 self.record_connection_metrics();
             }
@@ -659,6 +674,30 @@ impl SwarmDriver {
                 .set(self.swarm.connected_peers().count() as i64);
         }
     }
+
+    /// Insert into the latest connected peers list. This list does not contain all the connected peers.
+    /// Older entries are removed if the list exceeds 50.
+    fn insert_latest_connected_peers(&mut self, addr: Multiaddr) {
+        while self.latest_connected_peers.len() >= 50 {
+            // remove the oldest entry
+            let Some(oldest) = self
+                .latest_connected_peers
+                .iter()
+                .min_by_key(|(_, time)| *time)
+                .map(|(addr, _)| addr.clone())
+            else {
+                break;
+            };
+
+            self.latest_connected_peers.remove(&oldest);
+        }
+
+        let old_instant = self
+            .latest_connected_peers
+            .entry(addr)
+            .or_insert_with(Instant::now);
+        *old_instant = Instant::now();
+    }
 }
 
 /// Helper function to print formatted connection role info.