1 files changed, 38 insertions, 2 deletions

diff --git a/src/state.rs b/src/state.rs
index aae33f5..dfabf8f 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -144,6 +144,34 @@ pub(crate) struct PeerState {
     /// dormant). Cleared by any message from it; ignored after `dormant_probe`, so the
     /// peer becomes a neighbour candidate again and gets tried once more.
     pub(crate) unreachable_since: Option<Instant>,
+
+    /// What went wrong with this peer so far (counted only, for /peers and /admin/stats).
+    pub(crate) incidents: Incidents,
+}
+
+/// Trouble with a peer, counted since it was first listed. Lost keepalives and refused
+/// sends are in the traffic counters (`transport::traffic`): every PONG answers a PING.
+#[derive(Debug, Default, Clone, Copy, serde::Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub(crate) struct Incidents {
+    /// Our sync messages left unanswered until the reply timeout (then sent again).
+    pub(crate) reply_timeouts: u64,
+    /// Re-handshakes because our documents differed while sync was idle.
+    pub(crate) heals: u64,
+    /// Times the peer went dormant.
+    pub(crate) dormancies: u64,
+    /// Time spent dormant, in milliseconds, up to its last return (the current
+    /// dormancy, if any, isn't included).
+    pub(crate) dormant_ms: u64,
+}
+
+impl Incidents {
+    pub(crate) fn add(&mut self, other: &Incidents) {
+        self.reply_timeouts += other.reply_timeouts;
+        self.heals += other.heals;
+        self.dormancies += other.dormancies;
+        self.dormant_ms += other.dormant_ms;
+    }
 }
 
 /// Unanswered HELLOs after which a peer counts as unreachable (1 + 2 + 4 s apart).
@@ -296,6 +324,7 @@ impl PeerState {
             reported_heads: None,
             hello_attempts: 0,
             unreachable_since: None,
+            incidents: Incidents::default(),
         }
     }
 
@@ -311,7 +340,11 @@ impl PeerState {
         if self.liveness != Liveness::Active || self.hello_state != HelloState::Established {
             return None;
         }
-        self.sync.take_overdue_reply(now)
+        let overdue = self.sync.take_overdue_reply(now);
+        if overdue.is_some() {
+            self.incidents.reply_timeouts += 1;
+        }
+        overdue
     }
 
     fn quiet_for(&self, now: Instant) -> Duration {
@@ -324,7 +357,8 @@ impl PeerState {
         self.hello_attempts = 0;
         self.unreachable_since = None;
 
-        if matches!(self.liveness, Liveness::Dormant { .. }) {
+        if let Liveness::Dormant { since } = self.liveness {
+            self.incidents.dormant_ms += now.saturating_duration_since(since).as_millis() as u64;
             self.liveness = Liveness::Active;
             // Force a fresh handshake; its reply resets sync on both sides.
             if self.hello_state != HelloState::Sending {
@@ -365,6 +399,7 @@ impl PeerState {
         }
 
         self.liveness = Liveness::Dormant { since: now };
+        self.incidents.dormancies += 1;
         self.unreachable_since.get_or_insert(now);
         self.reset_sync();
 
@@ -446,6 +481,7 @@ impl PeerState {
             return false;
         }
         self.diverged_since = None;
+        self.incidents.heals += 1;
 
         self.last_resync_at = Some(now);
         self.hello_state = HelloState::NotSent; // establish_peer resets sync on the reply