debug: add logging for NodeGatheredInfo event flow

Track when NodeGatheredInfo events are sent and applied to help
diagnose why joining nodes stay as "unknown".

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Cargo.lock

@@ -514,20 +514,6 @@ version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a1d728cc89cf3aee9ff92b05e62b19ee65a02b5702cff7d5a377e32c6ae29d8d"
 
-[[package]]
-name = "cluster_membership"
-version = "0.0.1"
-dependencies = [
- "anyhow",
- "async-trait",
- "futures-lite",
- "futures-timer",
- "libp2p",
- "log",
- "tokio",
- "tracing-subscriber",
-]
-
 [[package]]
 name = "colorchoice"
 version = "1.0.4"
@@ -1012,7 +998,6 @@ dependencies = [
 name = "exo_pyo3_bindings"
 version = "0.0.1"
 dependencies = [
- "cluster_membership",
  "delegate",
  "derive_more",
  "env_logger",
@@ -1045,12 +1030,6 @@ dependencies = [
  "syn 2.0.111",
 ]
 
-[[package]]
-name = "fastrand"
-version = "2.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
-
 [[package]]
 name = "ff"
 version = "0.13.1"
@@ -1159,10 +1138,7 @@ version = "2.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f78e10609fe0e0b3f4157ffab1876319b5b0db102a2c60dc4626306dc46b44ad"
 dependencies = [
- "fastrand",
  "futures-core",
- "futures-io",
- "parking",
  "pin-project-lite",
 ]
 

Cargo.toml

@@ -4,7 +4,6 @@ members = [
     "rust/networking",
     "rust/exo_pyo3_bindings",
     "rust/util",
-    "rust/cluster_membership",
 ]
 
 [workspace.package]
@@ -26,7 +25,6 @@ opt-level = 3
 ## Crate members as common dependencies
 networking = { path = "rust/networking" }
 util = { path = "rust/util" }
-cluster_membership = { path = "rust/cluster_membership" }
 
 # Proc-macro authoring tools
 syn = "2.0"
@@ -64,7 +62,6 @@ frunk-enum-core = "0.3"
 # Async dependencies
 tokio = "1.46"
 futures = "0.3"
-futures-lite = "2.6.1"
 futures-util = "0.3"
 futures-timer = "3.0"
 

app/EXO/EXO/Services/NetworkSetupHelper.swift

@@ -31,35 +31,6 @@ enum NetworkSetupHelper {
         # Remove Thunderbolt Bridge from VirtualNetworkInterfaces in preferences.plist
         /usr/libexec/PlistBuddy -c "Delete :VirtualNetworkInterfaces:Bridge:bridge0" "$PREFS" 2>/dev/null || true
 
-        networksetup -listlocations | grep -q exo || {
-          networksetup -createlocation exo
-        }
-
-        networksetup -switchtolocation exo
-        networksetup -listallhardwareports \\
-          | awk -F': ' '/Hardware Port: / {print $2}' \\
-          | while IFS=":" read -r name; do
-              case "$name" in
-                "Ethernet Adapter"*)
-                        ;;
-                "Thunderbolt Bridge")
-                        ;;
-                "Thunderbolt "*)
-                  networksetup -listallnetworkservices \\
-                    | grep -q "EXO $name" \\
-                      || networksetup -createnetworkservice "EXO $name" "$name" 2>/dev/null \\
-                      || continue
-                  networksetup -setdhcp "EXO $name"
-                        ;;
-                *)
-                  networksetup -listallnetworkservices \\
-                    | grep -q "$name" \\
-                      || networksetup -createnetworkservice "$name" "$name" 2>/dev/null \\
-                      || continue
-                        ;;
-              esac
-            done
-
         networksetup -listnetworkservices | grep -q "Thunderbolt Bridge" && {
           networksetup -setnetworkserviceenabled "Thunderbolt Bridge" off
         } || true

dashboard/parts.nix

@@ -3,28 +3,12 @@
   perSystem =
     { pkgs, lib, ... }:
     let
-      # Filter source to ONLY include package.json and package-lock.json
-      # This ensures prettier-svelte only rebuilds when lockfiles change
-      dashboardLockfileSrc = lib.cleanSourceWith {
-        src = inputs.self;
-        filter =
-          path: type:
-          let
-            baseName = builtins.baseNameOf path;
-            isDashboardDir = baseName == "dashboard" && type == "directory";
-            isPackageFile =
-              (lib.hasInfix "/dashboard/" path || lib.hasSuffix "/dashboard" (builtins.dirOf path))
-              && (baseName == "package.json" || baseName == "package-lock.json");
-          in
-          isDashboardDir || isPackageFile;
-      };
-
       # Stub source with lockfiles and minimal files for build to succeed
       # This allows prettier-svelte to avoid rebuilding when dashboard source changes
       dashboardStubSrc = pkgs.runCommand "dashboard-stub-src" { } ''
         mkdir -p $out
-        cp ${dashboardLockfileSrc}/dashboard/package.json $out/
-        cp ${dashboardLockfileSrc}/dashboard/package-lock.json $out/
+        cp ${inputs.self}/dashboard/package.json $out/
+        cp ${inputs.self}/dashboard/package-lock.json $out/
         # Minimal files so vite build succeeds (produces empty output)
         echo '<!DOCTYPE html><html><head></head><body></body></html>' > $out/index.html
         mkdir -p $out/src

rust/cluster_membership/Cargo.toml

@@ -1,23 +0,0 @@
-[package]
-name = "cluster_membership"
-version.workspace = true
-edition.workspace = true
-publish = false
-
-[dependencies]
-# util
-anyhow.workspace = true
-log.workspace = true
-tracing-subscriber = { version = "0.3.19", features = ["default", "env-filter"] }
-
-# async
-tokio = { workspace = true, features = ["full"] }
-futures-timer = { workspace = true }
-futures-lite = "2.6.1"
-
-# networking
-libp2p = { workspace = true, features = ["full"] }
-async-trait = "0.1.89"
-
-[lints]
-workspace = true

rust/cluster_membership/examples/chatroom.rs

@@ -1,30 +0,0 @@
-use cluster_membership::Peer;
-use libp2p::identity::ed25519::SecretKey;
-use tokio::io::{self, AsyncBufReadExt};
-use tracing_subscriber::{EnvFilter, filter::LevelFilter};
-
-#[tokio::main]
-async fn main() {
-    let _ = tracing_subscriber::fmt()
-        .with_env_filter(EnvFilter::from_default_env().add_directive(LevelFilter::INFO.into()))
-        .try_init();
-
-    let (mut peer, send, mut recv) =
-        Peer::new(SecretKey::generate(), "hello".to_string()).expect("peer should always build");
-
-    let ch = peer.subscribe("chatroom".to_string());
-    let jh = tokio::spawn(async move { peer.run().await });
-
-    let mut stdin = io::BufReader::new(io::stdin()).lines();
-    loop {
-        tokio::select! {
-            Ok(Some(line)) = stdin.next_line() => {send.send((ch.clone(), line.into_bytes())).await.expect("example");}
-            Some(r) = recv.recv() => match r {
-                Ok((_, id, line)) => println!("{:?}:{:?}", id, String::from_utf8_lossy(&line)),
-                Err(e) => eprintln!("{e:?}"),
-            },
-            else => break
-        }
-    }
-    jh.await.expect("task failure");
-}

rust/cluster_membership/src/lib.rs

@@ -1,227 +0,0 @@
-use libp2p::{
-    Multiaddr, PeerId, Swarm, SwarmBuilder,
-    futures::StreamExt,
-    gossipsub::{self, PublishError, Sha256Topic, TopicHash},
-    identify,
-    identity::{Keypair, ed25519},
-    mdns,
-    swarm::{NetworkBehaviour, SwarmEvent, dial_opts::DialOpts},
-};
-use std::{
-    collections::HashMap,
-    time::{Duration, Instant},
-};
-use tokio::{select, sync::mpsc};
-
-const DEFAULT_BUFFER_SIZE: usize = 10;
-const MDNS_IGNORE_DURATION_SECS: u64 = 30;
-
-impl Peer {
-    pub fn new(
-        identity: ed25519::SecretKey,
-        namespace: String,
-    ) -> anyhow::Result<(
-        Self,
-        mpsc::Sender<(TopicHash, Vec<u8>)>,
-        mpsc::Receiver<Result<(TopicHash, PeerId, Vec<u8>), PublishError>>,
-    )> {
-        let mut id_bytes = identity.as_ref().to_vec();
-
-        let mut swarm =
-            SwarmBuilder::with_existing_identity(Keypair::ed25519_from_bytes(&mut id_bytes)?)
-                .with_tokio()
-                .with_quic()
-                // TODO(evan): .with_bandwidth_metrics();
-                .with_behaviour(|kp| Behaviour::new(kp, namespace.clone()))?
-                .build();
-
-        swarm.listen_on("/ip6/::/udp/0/quic-v1".parse()?)?;
-        swarm.listen_on("/ip4/0.0.0.0/udp/0/quic-v1".parse()?)?;
-        let (to_swarm, from_client) = mpsc::channel(DEFAULT_BUFFER_SIZE);
-        let (to_client, from_swarm) = mpsc::channel(DEFAULT_BUFFER_SIZE);
-        Ok((
-            Self {
-                swarm,
-                namespace,
-                denied: HashMap::new(),
-                from_client,
-                to_client,
-            },
-            to_swarm,
-            from_swarm,
-        ))
-    }
-
-    pub fn subscribe(&mut self, topic: String) -> TopicHash {
-        let topic = Sha256Topic::new(topic);
-        self.swarm
-            .behaviour_mut()
-            .gossipsub
-            .subscribe(&topic)
-            .expect("topic filtered");
-        topic.hash()
-    }
-
-    pub async fn run(&mut self) {
-        loop {
-            select! {
-                ev = self.swarm.select_next_some() => {
-                    let Ok(()) = self.handle_swarm_event(ev).await else {
-                        return
-                    };
-                },
-                Some(msg) = self.from_client.recv() => {
-                    if let Err(e) = self.swarm.behaviour_mut().gossipsub.publish(msg.0, msg.1) {
-                        let Ok(()) = self.to_client.send(Err(e)).await else {
-                            return
-                        };
-                    }
-                },
-            }
-        }
-    }
-
-    async fn handle_swarm_event(&mut self, event: SwarmEvent<BehaviourEvent>) -> Result<(), ()> {
-        let SwarmEvent::Behaviour(event) = event else {
-            if let SwarmEvent::NewListenAddr {
-                listener_id: _,
-                address,
-            } = event
-            {
-                log::info!("new listen address {address}")
-            }
-            return Ok(());
-        };
-        match event {
-            BehaviourEvent::Mdns(mdns_event) => match mdns_event {
-                mdns::Event::Discovered(vec) => {
-                    // Dial everyone
-                    let mut addrs = HashMap::<PeerId, Vec<Multiaddr>>::new();
-                    vec.into_iter()
-                        .filter(|(peer_id, _)| {
-                            self.denied.get(peer_id).is_none_or(|t| {
-                                t.elapsed() > Duration::from_secs(MDNS_IGNORE_DURATION_SECS)
-                            })
-                        })
-                        .for_each(|(peer_id, addr)| addrs.entry(peer_id).or_default().push(addr));
-                    addrs.into_iter().for_each(|(peer_id, addrs)| {
-                        let _ = self
-                            .swarm
-                            .dial(DialOpts::peer_id(peer_id).addresses(addrs).build());
-                    });
-                }
-                mdns::Event::Expired(vec) => {
-                    vec.iter().for_each(|(peer_id, _)| {
-                        log::debug!("{peer_id} no longer reachable on mDNS");
-                        self.swarm
-                            .behaviour_mut()
-                            .gossipsub
-                            .remove_explicit_peer(peer_id);
-                    });
-                }
-            },
-            BehaviourEvent::Identify(identify::Event::Received {
-                connection_id: _,
-                peer_id,
-                info,
-            }) => {
-                if info
-                    .protocols
-                    .iter()
-                    .any(|p| p.as_ref().contains(&self.namespace))
-                {
-                    self.passed_namespace(peer_id);
-                } else {
-                    self.failed_namespace(peer_id);
-                }
-            }
-            BehaviourEvent::Gossipsub(gossipsub::Event::Message {
-                propagation_source: _,
-                message_id: _,
-                message:
-                    gossipsub::Message {
-                        topic,
-                        data,
-                        source: Some(source_peer),
-                        ..
-                    },
-            }) => {
-                let Ok(()) = self.to_client.send(Ok((topic, source_peer, data))).await else {
-                    return Err(());
-                };
-            }
-            _ => {}
-        }
-        Ok(())
-    }
-
-    fn passed_namespace(&mut self, peer: PeerId) {
-        log::info!("new peer {peer:?}");
-        self.denied.remove(&peer);
-        self.swarm
-            .behaviour_mut()
-            .gossipsub
-            .remove_blacklisted_peer(&peer);
-        self.swarm
-            .behaviour_mut()
-            .gossipsub
-            .add_explicit_peer(&peer);
-    }
-
-    fn failed_namespace(&mut self, peer: PeerId) {
-        log::debug!("{peer} failed handshake");
-        self.denied.insert(peer, Instant::now());
-        self.swarm.behaviour_mut().gossipsub.blacklist_peer(&peer);
-        // we don't care if disconnect fails
-        let _ = self.swarm.disconnect_peer_id(peer);
-    }
-}
-
-pub struct Peer {
-    pub swarm: Swarm<Behaviour>,
-    denied: HashMap<PeerId, Instant>,
-    namespace: String,
-    to_client: mpsc::Sender<Result<(TopicHash, PeerId, Vec<u8>), PublishError>>,
-    from_client: mpsc::Receiver<(TopicHash, Vec<u8>)>,
-}
-
-#[test]
-fn foo() {
-    fn bar<T: Send>(t: T) {}
-    let p: Peer = unimplemented!();
-    bar(p);
-}
-
-#[derive(NetworkBehaviour)]
-pub struct Behaviour {
-    mdns: mdns::tokio::Behaviour,
-    pub gossipsub: gossipsub::Behaviour,
-    identify: identify::Behaviour,
-}
-
-impl Behaviour {
-    fn new(kp: &Keypair, namespace: String) -> Self {
-        let mdns = mdns::tokio::Behaviour::new(Default::default(), kp.public().to_peer_id())
-            .expect("implementation is infallible");
-        let gossipsub = gossipsub::Behaviour::new(
-            gossipsub::MessageAuthenticity::Signed(kp.clone()),
-            gossipsub::ConfigBuilder::default()
-                .max_transmit_size(1024 * 1024)
-                .protocol_id_prefix(format!("/exo/gossip/{namespace}/v1"))
-                .build()
-                .expect("fixed gossipsub config should always build"),
-        )
-        .expect("fixed gossipsub init should always build");
-
-        let identify = identify::Behaviour::new(
-            identify::Config::new_with_signed_peer_record(format!("/exo/identity/v1"), kp)
-                .with_push_listen_addr_updates(true),
-        );
-
-        Behaviour {
-            mdns,
-            gossipsub,
-            identify,
-        }
-    }
-}

rust/exo_pyo3_bindings/Cargo.toml

@@ -22,7 +22,6 @@ doc = false
 workspace = true
 
 [dependencies]
-cluster_membership.workspace = true
 networking = { workspace = true }
 
 # interop

rust/exo_pyo3_bindings/src/pylibp2p/mod.rs

@@ -6,41 +6,3 @@
 
 pub mod ident;
 pub mod multiaddr;
-
-use std::sync::Mutex;
-
-use cluster_membership::Peer;
-use libp2p::identity::ed25519::Keypair;
-use pyo3::prelude::*;
-use pyo3_stub_gen::derive::{gen_stub_pyclass, gen_stub_pymethods};
-
-#[gen_stub_pyclass]
-#[pyclass]
-#[derive(Clone)]
-pub struct PyKeypair(Keypair);
-
-#[gen_stub_pymethods]
-#[pymethods]
-impl PyKeypair {
-    #[staticmethod]
-    fn generate() -> Self {
-        Self(Keypair::generate())
-    }
-}
-
-#[gen_stub_pyclass]
-#[pyclass]
-pub struct PyPeer(Mutex<Peer>);
-
-#[gen_stub_pymethods]
-#[pymethods]
-impl PyPeer {
-    #[staticmethod]
-    fn init(kp: PyKeypair, namespace: String) -> PyResult<Self> {
-        Ok(PyPeer(Mutex::new(
-            Peer::new(kp.0.secret(), namespace)
-                .map_err(|e| e.pyerr())?
-                .0,
-        )))
-    }
-}

src/exo/main.py

@@ -53,6 +53,7 @@ class Node:
         await router.register_topic(topics.COMMANDS)
         await router.register_topic(topics.ELECTION_MESSAGES)
         await router.register_topic(topics.CONNECTION_MESSAGES)
+        await router.register_topic(topics.STATE_CATCHUP)
         await router.register_topic(topics.DOWNLOAD_COMMANDS)
 
         logger.info(f"Starting node {node_id}")
@@ -82,6 +83,7 @@ class Node:
                 command_sender=router.sender(topics.COMMANDS),
                 download_command_sender=router.sender(topics.DOWNLOAD_COMMANDS),
                 election_receiver=router.receiver(topics.ELECTION_MESSAGES),
+                state_catchup_receiver=router.receiver(topics.STATE_CATCHUP),
             )
         else:
             api = None
@@ -94,6 +96,7 @@ class Node:
                 global_event_receiver=router.receiver(topics.GLOBAL_EVENTS),
                 local_event_sender=router.sender(topics.LOCAL_EVENTS),
                 command_sender=router.sender(topics.COMMANDS),
+                state_catchup_receiver=router.receiver(topics.STATE_CATCHUP),
                 download_command_sender=router.sender(topics.DOWNLOAD_COMMANDS),
                 event_index_counter=event_index_counter,
             )
@@ -107,6 +110,7 @@ class Node:
             global_event_sender=router.sender(topics.GLOBAL_EVENTS),
             local_event_receiver=router.receiver(topics.LOCAL_EVENTS),
             command_receiver=router.receiver(topics.COMMANDS),
+            state_catchup_sender=router.sender(topics.STATE_CATCHUP),
         )
 
         er_send, er_recv = channel[ElectionResult]()
@@ -189,6 +193,7 @@ class Node:
                         global_event_sender=self.router.sender(topics.GLOBAL_EVENTS),
                         local_event_receiver=self.router.receiver(topics.LOCAL_EVENTS),
                         command_receiver=self.router.receiver(topics.COMMANDS),
+                        state_catchup_sender=self.router.sender(topics.STATE_CATCHUP),
                     )
                     self._tg.start_soon(self.master.run)
                 elif (
@@ -235,6 +240,9 @@ class Node:
                             ),
                             local_event_sender=self.router.sender(topics.LOCAL_EVENTS),
                             command_sender=self.router.sender(topics.COMMANDS),
+                            state_catchup_receiver=self.router.receiver(
+                                topics.STATE_CATCHUP
+                            ),
                             download_command_sender=self.router.sender(
                                 topics.DOWNLOAD_COMMANDS
                             ),

src/exo/master/api.py

@@ -166,6 +166,7 @@ class API:
         download_command_sender: Sender[ForwarderDownloadCommand],
         # This lets us pause the API if an election is running
         election_receiver: Receiver[ElectionMessage],
+        state_catchup_receiver: Receiver[State],
     ) -> None:
         self.state = State()
         self._event_log: list[Event] = []
@@ -173,6 +174,7 @@ class API:
         self.download_command_sender = download_command_sender
         self.global_event_receiver = global_event_receiver
         self.election_receiver = election_receiver
+        self.state_catchup_receiver = state_catchup_receiver
         self.event_buffer: OrderedBuffer[Event] = OrderedBuffer[Event]()
         self.node_id: NodeId = node_id
         self.session_id: SessionId = session_id
@@ -1249,6 +1251,7 @@ class API:
             tg.start_soon(self._apply_state)
             tg.start_soon(self._pause_on_new_election)
             tg.start_soon(self._cleanup_expired_images)
+            tg.start_soon(self._state_catchup)
             print_startup_banner(self.port)
             await serve(
                 cast(ASGIFramework, self.app),
@@ -1259,6 +1262,37 @@ class API:
         self.command_sender.close()
         self.global_event_receiver.close()
 
+    async def _state_catchup(self):
+        with self.state_catchup_receiver as states:
+            async for state in states:
+                if (
+                    self.state.last_event_applied_idx == -1
+                    and state.last_event_applied_idx > self.state.last_event_applied_idx
+                ):
+                    # DEBUG: Log buffer state BEFORE clearing
+                    logger.warning(
+                        f"STATE_CATCHUP: About to catch up. "
+                        f"Current buffer indices: {sorted(self.event_buffer.store.keys())}, "
+                        f"next_idx_to_release: {self.event_buffer.next_idx_to_release}, "
+                        f"catching up to idx: {state.last_event_applied_idx}"
+                    )
+
+                    new_idx = state.last_event_applied_idx + 1
+                    self.event_buffer.next_idx_to_release = new_idx
+                    # Preserve events that arrived early but are still valid (idx >= new_idx)
+                    # Remove stale events (idx < new_idx) to prevent memory growth
+                    self.event_buffer.store = {
+                        k: v for k, v in self.event_buffer.store.items() if k >= new_idx
+                    }
+                    self.state = state
+
+                    # DEBUG: Log buffer state AFTER clearing
+                    logger.warning(
+                        f"STATE_CATCHUP: Catchup complete. "
+                        f"Buffer preserved indices: {sorted(self.event_buffer.store.keys())}, "
+                        f"new next_idx_to_release: {self.event_buffer.next_idx_to_release}"
+                    )
+
     async def _apply_state(self):
         with self.global_event_receiver as events:
             async for f_event in events:

src/exo/master/main.py

@@ -68,6 +68,8 @@ class Master:
         # Send events to the forwarder to be indexed (usually from command processing)
         # Ideally these would be MasterForwarderEvents but type system says no :(
         global_event_sender: Sender[ForwarderEvent],
+        # not a fan but - send the entire state to a node so it can catchup without the whole event log.
+        state_catchup_sender: Sender[State],
     ):
         self.state = State()
         self._tg: TaskGroup = anyio.create_task_group()
@@ -77,6 +79,7 @@ class Master:
         self.command_receiver = command_receiver
         self.local_event_receiver = local_event_receiver
         self.global_event_sender = global_event_sender
+        self.state_catchup_sender = state_catchup_sender
         send, recv = channel[Event]()
         self.event_sender: Sender[Event] = send
         self._loopback_event_receiver: Receiver[Event] = recv
@@ -84,7 +87,6 @@ class Master:
             local_event_receiver.clone_sender()
         )
         self._multi_buffer = MultiSourceBuffer[NodeId, Event]()
-        # TODO: not have this
         self._event_log: list[Event] = []
 
     async def run(self):
@@ -291,11 +293,17 @@ class Master:
                                     command.finished_command_id
                                 ]
                         case RequestEventLog():
-                            # We should just be able to send everything, since other buffers will ignore old messages
-                            for i in range(command.since_idx, len(self._event_log)):
-                                await self._send_event(
-                                    IndexedEvent(idx=i, event=self._event_log[i])
+                            if command.since_idx == 0:
+                                # This is an optimization, and should not be relied upon in theory.
+                                logger.info(
+                                    f"Master sending catchup state for index {self.state.last_event_applied_idx}"
                                 )
+                                await self.state_catchup_sender.send(self.state)
+                            else:
+                                for i in range(command.since_idx, len(self._event_log)):
+                                    await self._send_event(
+                                        IndexedEvent(idx=i, event=self._event_log[i])
+                                    )
                     for event in generated_events:
                         await self.event_sender.send(event)
                 except ValueError as e:

src/exo/master/tests/test_master.py

@@ -27,6 +27,7 @@ from exo.shared.types.memory import Memory
 from exo.shared.types.profiling import (
     MemoryUsage,
 )
+from exo.shared.types.state import State
 from exo.shared.types.tasks import ChatCompletion as ChatCompletionTask
 from exo.shared.types.tasks import TaskStatus
 from exo.shared.types.worker.instances import (
@@ -47,6 +48,7 @@ async def test_master():
     ge_sender, global_event_receiver = channel[ForwarderEvent]()
     command_sender, co_receiver = channel[ForwarderCommand]()
     local_event_sender, le_receiver = channel[ForwarderEvent]()
+    st_s, _st_r = channel[State]()
 
     all_events: list[IndexedEvent] = []
 
@@ -67,6 +69,7 @@ async def test_master():
         global_event_sender=ge_sender,
         local_event_receiver=le_receiver,
         command_receiver=co_receiver,
+        state_catchup_sender=st_s,
     )
     logger.info("run the master")
     async with anyio.create_task_group() as tg:

src/exo/routing/topics.py

@@ -7,6 +7,7 @@ from exo.shared.types.commands import ForwarderCommand, ForwarderDownloadCommand
 from exo.shared.types.events import (
     ForwarderEvent,
 )
+from exo.shared.types.state import State
 from exo.utils.pydantic_ext import CamelCaseModel
 
 
@@ -45,6 +46,7 @@ ELECTION_MESSAGES = TypedTopic(
 CONNECTION_MESSAGES = TypedTopic(
     "connection_messages", PublishPolicy.Never, ConnectionMessage
 )
+STATE_CATCHUP = TypedTopic("state_catchup", PublishPolicy.Always, State)
 DOWNLOAD_COMMANDS = TypedTopic(
     "download_commands", PublishPolicy.Always, ForwarderDownloadCommand
 )

src/exo/utils/info_gatherer/info_gatherer.py

@@ -349,8 +349,13 @@ class InfoGatherer:
     async def _monitor_misc(self):
         if self.misc_poll_interval is None:
             return
+        prev = await MiscData.gather()
+        await self.info_sender.send(prev)
         while True:
-            await self.info_sender.send(await MiscData.gather())
+            curr = await MiscData.gather()
+            if prev != curr:
+                prev = curr
+                await self.info_sender.send(curr)
             await anyio.sleep(self.misc_poll_interval)
 
     async def _monitor_system_profiler_thunderbolt_data(self):
@@ -360,12 +365,15 @@ class InfoGatherer:
         if iface_map is None:
             return
 
+        old_idents = []
         while True:
             data = await ThunderboltConnectivity.gather()
             assert data is not None
 
             idents = [it for i in data if (it := i.ident(iface_map)) is not None]
-            await self.info_sender.send(MacThunderboltIdentifiers(idents=idents))
+            if idents != old_idents:
+                await self.info_sender.send(MacThunderboltIdentifiers(idents=idents))
+            old_idents = idents
 
             conns = [it for i in data if (it := i.conn()) is not None]
             await self.info_sender.send(MacThunderboltConnections(conns=conns))
@@ -390,17 +398,22 @@ class InfoGatherer:
     async def _watch_system_info(self):
         if self.interface_watcher_interval is None:
             return
+        old_nics = []
         while True:
             nics = await get_network_interfaces()
-            await self.info_sender.send(NodeNetworkInterfaces(ifaces=nics))
+            if nics != old_nics:
+                old_nics = nics
+                await self.info_sender.send(NodeNetworkInterfaces(ifaces=nics))
             await anyio.sleep(self.interface_watcher_interval)
 
     async def _monitor_thunderbolt_bridge_status(self):
         if self.thunderbolt_bridge_poll_interval is None:
             return
+        prev: ThunderboltBridgeInfo | None = None
         while True:
             curr = await ThunderboltBridgeInfo.gather()
-            if curr is not None:
+            if curr is not None and prev != curr:
+                prev = curr
                 await self.info_sender.send(curr)
             await anyio.sleep(self.thunderbolt_bridge_poll_interval)
 

src/exo/worker/main.py

@@ -60,9 +60,8 @@ class Worker:
         connection_message_receiver: Receiver[ConnectionMessage],
         global_event_receiver: Receiver[ForwarderEvent],
         local_event_sender: Sender[ForwarderEvent],
-        # This is for requesting updates. It doesn't need to be a general command sender right now,
-        # but I think it's the correct way to be thinking about commands
         command_sender: Sender[ForwarderCommand],
+        state_catchup_receiver: Receiver[State],
         download_command_sender: Sender[ForwarderDownloadCommand],
         event_index_counter: Iterator[int],
     ):
@@ -71,6 +70,8 @@ class Worker:
 
         self.global_event_receiver = global_event_receiver
         self.local_event_sender = local_event_sender
+        self.state_catchup_receiver = state_catchup_receiver
+        self.local_event_index = 0
         self.event_index_counter = event_index_counter
         self.command_sender = command_sender
         self.download_command_sender = download_command_sender
@@ -110,6 +111,7 @@ class Worker:
             tg.start_soon(self._event_applier)
             tg.start_soon(self._forward_events)
             tg.start_soon(self._poll_connection_updates)
+            tg.start_soon(self._check_catchup_state)
 
         # Actual shutdown code - waits for all tasks to complete before executing.
         self.local_event_sender.close()
@@ -121,13 +123,47 @@ class Worker:
     async def _forward_info(self, recv: Receiver[GatheredInfo]):
         with recv as info_stream:
             async for info in info_stream:
-                await self.event_sender.send(
-                    NodeGatheredInfo(
-                        node_id=self.node_id,
-                        when=str(datetime.now(tz=timezone.utc)),
-                        info=info,
-                    )
+                event = NodeGatheredInfo(
+                    node_id=self.node_id,
+                    when=str(datetime.now(tz=timezone.utc)),
+                    info=info,
                 )
+                logger.warning(
+                    f"NODE_GATHERED_INFO: Sending event for node {self.node_id}, "
+                    f"event_id={event.event_id}"
+                )
+                await self.event_sender.send(event)
+
+    async def _check_catchup_state(self):
+        with self.state_catchup_receiver as states:
+            async for state in states:
+                if (
+                    self.state.last_event_applied_idx == -1
+                    and state.last_event_applied_idx > self.state.last_event_applied_idx
+                ):
+                    # DEBUG: Log buffer state BEFORE clearing
+                    logger.warning(
+                        f"STATE_CATCHUP: About to catch up. "
+                        f"Current buffer indices: {sorted(self.event_buffer.store.keys())}, "
+                        f"next_idx_to_release: {self.event_buffer.next_idx_to_release}, "
+                        f"catching up to idx: {state.last_event_applied_idx}"
+                    )
+
+                    new_idx = state.last_event_applied_idx + 1
+                    self.event_buffer.next_idx_to_release = new_idx
+                    # Preserve events that arrived early but are still valid (idx >= new_idx)
+                    # Remove stale events (idx < new_idx) to prevent memory growth
+                    self.event_buffer.store = {
+                        k: v for k, v in self.event_buffer.store.items() if k >= new_idx
+                    }
+                    self.state = state
+
+                    # DEBUG: Log buffer state AFTER clearing
+                    logger.warning(
+                        f"STATE_CATCHUP: Catchup complete. "
+                        f"Buffer preserved indices: {sorted(self.event_buffer.store.keys())}, "
+                        f"new next_idx_to_release: {self.event_buffer.next_idx_to_release}"
+                    )
 
     async def _event_applier(self):
         with self.global_event_receiver as events:
@@ -139,8 +175,20 @@ class Worker:
                 if event_id in self.out_for_delivery:
                     del self.out_for_delivery[event_id]
 
+                # DEBUG: Log what was ingested
+                logger.warning(
+                    f"EVENT_APPLIER: Ingested event idx={f_event.origin_idx}, "
+                    f"buffer keys now: {sorted(self.event_buffer.store.keys())}"
+                )
+
                 # 2. for each event, apply it to the state
                 indexed_events = self.event_buffer.drain_indexed()
+
+                # DEBUG: Log drain results
+                logger.warning(
+                    f"EVENT_APPLIER: Drained {len(indexed_events)} events, "
+                    f"next_idx_to_release now: {self.event_buffer.next_idx_to_release}"
+                )
                 if indexed_events:
                     self._nack_attempts = 0
 
@@ -157,6 +205,12 @@ class Worker:
                     self._nack_cancel_scope.cancel()
 
                 for idx, event in indexed_events:
+                    # DEBUG: Log NodeGatheredInfo events
+                    if isinstance(event, NodeGatheredInfo):
+                        logger.warning(
+                            f"NODE_GATHERED_INFO: Applying event idx={idx} for node {event.node_id}, "
+                            f"event_id={event.event_id}"
+                        )
                     self.state = apply(self.state, IndexedEvent(idx=idx, event=event))
 
                     # Buffer input image chunks for image editing
@@ -318,10 +372,7 @@ class Worker:
         # We request all events after (and including) the missing index.
         # This function is started whenever we receive an event that is out of sequence.
         # It is cancelled as soon as we receiver an event that is in sequence.
-
-        if since_idx < 0:
-            logger.warning(f"Negative value encountered for nack request {since_idx=}")
-            since_idx = 0
+        assert since_idx >= 0
 
         with CancelScope() as scope:
             self._nack_cancel_scope = scope