perf(runtime): bound telemetry and hot-path work

Cap and fairly distribute live snapshots, serialize dashboard refreshes, reduce telemetry fanout copies, and use a faster codec registry map.

Cargo.lock

@@ -4349,6 +4349,7 @@ dependencies = [
  "ed25519-dalek 2.2.0",
  "proptest",
  "rand_core 0.6.4",
+ "rustc-hash",
  "serde",
  "serde_json",
  "swactor",

crates/dashboard/README.md

@@ -20,7 +20,7 @@ is hard-capped at 50.
 - `GET /api/frames` — recent raw frame window
 - `GET /api/views` — registered view metadata
 - `GET /view/telemetry/live` — generic live explorer over retained and incoming telemetry frames
-- `GET /api/view/telemetry/live` — 2,000 frames per stream/channel, newest lifetime per node, all live streams plus 50 stale streams
+- `GET /api/view/telemetry/live` — bounded bootstrap snapshot: up to 500 recent frames and 256 KiB of raw payload, distributed across channels; retention remains 500 frames per stream/channel for live inspection
 - `GET /view/fleet` — fused control-plane page (machine + actors per node)
 - `GET /api/view/fleet` — live/stale pools with per-node machine and roster snapshot
 - `GET /api/view/fleet/detail?stream=<node#life>&actor=<addr>` — bounded per-actor dossier detail (diet, history, sampled receipts)

crates/dashboard/src/control_plane_page.html

@@ -173,6 +173,7 @@ let rosterSort = { key: 'address', direction: 'asc' };
 let hardwareSource = 'node';
 let lastSnapshot = null;
 let detailTimer = null;
+let refreshInFlight = false;
 // A1: last-rendered HTML per region. A poll that yields identical markup
 // must not swap innerHTML — the swap destroyed hover/selection/presses and
 // restarted animations every second even in a fully converged steady state.
@@ -256,13 +257,18 @@ function pushUrl() {
 }
 
 async function refresh() {
-  let data;
+  if (refreshInFlight) return;
+  refreshInFlight = true;
   try {
     const response = await fetch('/api/view/fleet');
-    data = await response.json();
+    const data = await response.json();
-  } catch { return; }
     lastSnapshot = data;
     render();
+  } catch {
+    // Keep the last good snapshot while the next scheduled refresh retries.
+  } finally {
+    refreshInFlight = false;
+  }
 }
 
 function render() {
@@ -681,15 +687,20 @@ function stopDetailPolling() {
 
 function startDetailPolling() {
   stopDetailPolling();
+  let pollInFlight = false;
   const poll = async () => {
-    if (!selectedStream || !selectedActor) return;
+    if (!selectedStream || !selectedActor || pollInFlight) return;
-    let detail;
+    pollInFlight = true;
     try {
       const response = await fetch(`/api/view/fleet/detail?stream=${encodeURIComponent(selectedStream)}&actor=${encodeURIComponent(selectedActor)}`);
       if (!response.ok) { stopDetailPolling(); return; }
-      detail = await response.json();
+      const detail = await response.json();
-    } catch { return; }
       renderDossier(detail);
+    } catch {
+      // Keep the current dossier while the next scheduled refresh retries.
+    } finally {
+      pollInFlight = false;
+    }
   };
   poll();
   detailTimer = setInterval(poll, POLL_MS);

crates/dashboard/src/live_explorer.rs

@@ -9,7 +9,9 @@ use crate::FrameEvent;
 use crate::view::DashboardView;
 
 const LIVE_EXPLORER_HTML: &str = include_str!("live_explorer_page.html");
-const FRAME_HISTORY_CAP: usize = 2_000;
+const FRAME_HISTORY_CAP: usize = 500;
+const SNAPSHOT_FRAME_CAP: usize = 500;
+const SNAPSHOT_PAYLOAD_BYTE_CAP: usize = 256 * 1024;
 const LIVE_TTL: Duration = Duration::from_secs(8);
 const STALE_STREAM_CAP: usize = 50;
 
@@ -65,12 +67,39 @@ impl LiveTelemetryExplorer {
     fn snapshot_at(&self, now: Instant) -> Value {
         let mut state = self.state.write();
         prune_stale(&mut state.streams, now);
-        let mut frames = state
+
+        // Take recent frames round-robin across channels so a busy channel
+        // cannot crowd quiet channels out of the bounded bootstrap snapshot.
+        let mut channels = state
             .streams
             .values()
             .flat_map(|stream| stream.channels.values())
-            .flat_map(|frames| frames.iter())
+            .map(|frames| frames.iter().rev())
             .collect::<Vec<_>>();
+        let mut frames = Vec::with_capacity(SNAPSHOT_FRAME_CAP.min(channels.len()));
+        let mut payload_bytes = 0;
+        'snapshot: loop {
+            let mut found_frame = false;
+            for channel in &mut channels {
+                let Some(frame) = channel.next() else {
+                    continue;
+                };
+                found_frame = true;
+                if frame.payload.len() > SNAPSHOT_PAYLOAD_BYTE_CAP - payload_bytes {
+                    continue;
+                }
+                payload_bytes += frame.payload.len();
+                frames.push(frame.clone());
+                if frames.len() == SNAPSHOT_FRAME_CAP {
+                    break 'snapshot;
+                }
+            }
+            if !found_frame || payload_bytes == SNAPSHOT_PAYLOAD_BYTE_CAP {
+                break;
+            }
+        }
+        drop(state);
+
         frames.sort_by(|left, right| {
             left.stream
                 .node
@@ -138,6 +167,16 @@ mod tests {
         for position in 0..=FRAME_HISTORY_CAP as u64 {
             ingest(&view, &stream, "busy", position);
         }
+        {
+            let state = view.state.read();
+            let busy = &state.streams.values().next().expect("stream").channels["busy"];
+            assert_eq!(busy.len(), FRAME_HISTORY_CAP);
+            assert_eq!(busy.front().map(|frame| frame.position), Some(1));
+            assert_eq!(
+                busy.back().map(|frame| frame.position),
+                Some(FRAME_HISTORY_CAP as u64)
+            );
+        }
 
         let snapshot = view.snapshot_json();
         let frames = snapshot["frames"].as_array().expect("frames array");
@@ -151,11 +190,7 @@ mod tests {
             .collect::<Vec<_>>();
 
         assert_eq!(quiet.len(), 1, "a quiet channel remains discoverable");
-        assert_eq!(busy.len(), FRAME_HISTORY_CAP);
+        assert_eq!(busy.len(), SNAPSHOT_FRAME_CAP - quiet.len());
-        assert_eq!(
-            busy.first().and_then(|frame| frame["position"].as_u64()),
-            Some(1)
-        );
         assert_eq!(
             busy.last().and_then(|frame| frame["position"].as_u64()),
             Some(FRAME_HISTORY_CAP as u64)
@@ -201,6 +236,37 @@ mod tests {
         assert!(streams.contains("node-59"));
     }
 
+    #[test]
+    fn snapshot_payload_is_bounded() {
+        let view = LiveTelemetryExplorer::default();
+        let stream = StreamId::new(NodeId::new("node-a"), Lifetime(1));
+        let payload = vec![7; SNAPSHOT_PAYLOAD_BYTE_CAP / 2];
+        for (position, channel) in ["first", "second", "third"].into_iter().enumerate() {
+            let event = FrameEvent {
+                stream: crate::StreamEvent {
+                    node: stream.node.as_str().to_owned(),
+                    life: stream.life.0,
+                    origin: None,
+                    label: None,
+                },
+                channel: channel.to_owned(),
+                position: position as u64,
+                payload: payload.clone(),
+            };
+            view.ingest_at(&event, Instant::now());
+        }
+
+        let snapshot = view.snapshot_json();
+        let frames = snapshot["frames"].as_array().expect("frames array");
+        let payload_bytes = frames
+            .iter()
+            .map(|frame| frame["payload"].as_array().expect("payload").len())
+            .sum::<usize>();
+        assert!(frames.len() <= SNAPSHOT_FRAME_CAP);
+        assert!(payload_bytes <= SNAPSHOT_PAYLOAD_BYTE_CAP);
+        assert_eq!(frames.len(), 2, "the payload byte cap bounds the snapshot");
+    }
+
     fn test_frame(position: u64) -> Frame {
         Frame::new(
             ChannelId(position as u32 + 1),

crates/dashboard/src/live_explorer_page.html

@@ -147,6 +147,8 @@ RISK: terminal cosplay if decoration creeps past data; held by the palette law.
     seq: 0,
     paintQueued: false,
     paintHandle: 0,
+    reconciling: false,
+    reconcilePending: false,
   };
 
   const dirty = {
@@ -523,6 +525,11 @@ RISK: terminal cosplay if decoration creeps past data; held by the palette law.
       state.messageVersion++;
       updateMetrics();
     }
+    if (state.reconciling) {
+      state.reconcilePending = true;
+      return;
+    }
+    state.reconciling = true;
     const messageVersion = state.messageVersion;
     const startedAt = performance.now();
     try {
@@ -554,6 +561,12 @@ RISK: terminal cosplay if decoration creeps past data; held by the palette law.
         updateMetrics();
         renderDetail();
       }
+    } finally {
+      state.reconciling = false;
+      if (state.reconcilePending) {
+        state.reconcilePending = false;
+        reconcileSnapshot({ notice: 'Catching up after concurrent telemetry updates.' });
+      }
     }
   }
 

crates/telemetry/src/endpoint.rs

@@ -112,7 +112,7 @@ impl TelemetrySubscription {
     }
 
     pub fn drain_available(&self) -> Vec<TelemetryEvent> {
-        let mut out = Vec::new();
+        let mut out = Vec::with_capacity(self.rx.len());
         while let Ok(event) = self.rx.try_recv() {
             out.push(event);
         }
@@ -137,6 +137,31 @@ struct FanoutReport {
     disconnected: bool,
 }
 
+fn publish_to_target(
+    target: FanoutTarget,
+    events: impl IntoIterator<Item = TelemetryEvent>,
+) -> (usize, Option<FanoutReport>) {
+    let mut delivered = 0;
+    let mut dropped = 0;
+    let mut disconnected = false;
+    for event in events {
+        match target.tx.try_send(event) {
+            Ok(()) => delivered += 1,
+            Err(TrySendError::Full(_)) => dropped += 1,
+            Err(TrySendError::Disconnected(_)) => {
+                dropped += 1;
+                disconnected = true;
+            }
+        }
+    }
+    let report = (dropped > 0 || disconnected).then_some(FanoutReport {
+        id: target.id,
+        dropped,
+        disconnected,
+    });
+    (delivered, report)
+}
+
 struct FanoutState {
     next_id: u64,
     subscribers: BTreeMap<SubscriptionId, SubscriberSlot>,
@@ -236,11 +261,12 @@ impl DeliveryFanout {
         if events.is_empty() {
             return EndpointTick::default();
         }
+        let drained = events.len();
 
         // Snapshot sender handles while holding the subscriber map lock, then
         // deliver outside the lock so large batches or slow subscribers do not
         // block subscribe/snapshot control-plane operations.
-        let (targets, subscribers) = {
+        let (mut targets, subscribers) = {
             let state = self.state.lock().expect("telemetry fanout poisoned");
             let subscribers = state.subscribers.len();
             let targets = state
@@ -256,7 +282,7 @@ impl DeliveryFanout {
 
         if targets.is_empty() {
             return EndpointTick {
-                drained: events.len(),
+                drained,
                 subscribers: 0,
                 ..EndpointTick::default()
             };
@@ -264,26 +290,18 @@ impl DeliveryFanout {
 
         let mut delivered = 0;
         let mut reports = Vec::new();
+        let last_target = targets.pop().expect("nonempty fanout targets");
         for target in targets {
-            let mut dropped = 0;
+            let (target_delivered, report) = publish_to_target(target, events.iter().cloned());
-            let mut disconnected = false;
+            delivered += target_delivered;
-            for event in &events {
+            if let Some(report) = report {
-                match target.tx.try_send(event.clone()) {
+                reports.push(report);
-                    Ok(()) => delivered += 1,
-                    Err(TrySendError::Full(_)) => dropped += 1,
-                    Err(TrySendError::Disconnected(_)) => {
-                        dropped += 1;
-                        disconnected = true;
             }
         }
-            }
+        let (target_delivered, report) = publish_to_target(last_target, events);
-            if dropped > 0 || disconnected {
+        delivered += target_delivered;
-                reports.push(FanoutReport {
+        if let Some(report) = report {
-                    id: target.id,
+            reports.push(report);
-                    dropped,
-                    disconnected,
-                });
-            }
         }
 
         let dropped_for_subscribers = reports.iter().map(|report| report.dropped).sum::<u64>();
@@ -302,7 +320,7 @@ impl DeliveryFanout {
         }
 
         EndpointTick {
-            drained: events.len(),
+            drained,
             delivered,
             dropped_for_subscribers: usize::try_from(dropped_for_subscribers).unwrap_or(usize::MAX),
             subscribers,

crates/telemetry/src/store.rs

@@ -143,6 +143,9 @@ impl Store {
 
     /// The stored stream for a node's life, creating an empty one if needed.
     pub fn stream_mut(&mut self, id: &StreamId) -> &mut StoredStream {
+        if self.streams.contains_key(id) {
+            return self.streams.get_mut(id).expect("stream checked as present");
+        }
         self.streams.entry(id.clone()).or_default()
     }
 

crates/transport/Cargo.toml

@@ -14,6 +14,7 @@ ed25519-dalek = { version = "2", features = ["std", "rand_core", "serde"] }
 rand_core = { version = "0.6", features = ["getrandom"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
+rustc-hash = "2"
 
 [dev-dependencies]
 proptest = "1"

crates/transport/src/codec.rs

@@ -5,6 +5,7 @@
 //! per-type encoders/decoders so a type-erased message can be put on the wire
 //! and a [`WireEnvelope`] can be turned back into a concrete message.
 
+use rustc_hash::FxHashMap;
 use std::any::{Any, TypeId};
 use std::collections::HashMap;
 use std::sync::Arc;
@@ -150,7 +151,7 @@ type DecodeFn = Box<dyn Fn(&[u8]) -> Result<Box<dyn Any + Send>, Error> + Send +
 /// [`register_decoder`](Self::register_decoder) (variant-multiplexing encode,
 /// fan-in decode), then shared read-only via `Arc`.
 pub struct CodecRegistry {
-    encoders: HashMap<TypeId, EncodeFn>,
+    encoders: FxHashMap<TypeId, EncodeFn>,
     decoders: HashMap<String, DecodeFn>,
 }
 
@@ -163,7 +164,7 @@ impl Default for CodecRegistry {
 impl CodecRegistry {
     pub fn new() -> Self {
         Self {
-            encoders: HashMap::new(),
+            encoders: FxHashMap::default(),
             decoders: HashMap::new(),
         }
     }