NethermindEth
diff --git a/‎Cargo.lock‎
Lines changed: 1 addition & 0 deletions b/‎Cargo.lock‎
Lines changed: 1 addition & 0 deletions
diff --git a/‎Cargo.toml‎
Lines changed: 1 addition & 0 deletions b/‎Cargo.toml‎
Lines changed: 1 addition & 0 deletions
diff --git a/‎crates/core/Cargo.toml‎
Lines changed: 1 addition & 0 deletions b/‎crates/core/Cargo.toml‎
Lines changed: 1 addition & 0 deletions
diff --git a/‎crates/core/src/dutydb/memory.rs‎
Lines changed: 191 additions & 20 deletions b/‎crates/core/src/dutydb/memory.rs‎
Lines changed: 191 additions & 20 deletions
@@ -106,6 +106,7 @@ tree_hash_derive = "0.12"
 tar = "0.4"
 flate2 = "1.1"
 wiremock = "0.6"
+tower = "0.5"
 sysinfo = "0.33"
 quick-xml = { version = "0.39", features = ["serialize"] }
 
 
@@ -56,6 +56,7 @@ pluto-testutil.workspace = true
 pluto-tracing.workspace = true
 tokio = { workspace = true, features = ["test-util"] }
 wiremock.workspace = true
+tower = { workspace = true, features = ["util"] }
 
 [build-dependencies]
 pluto-build-proto.workspace = true
 
@@ -49,6 +49,12 @@ pub enum Error {
     #[error("dutydb shutdown: query could not be answered")]
     Shutdown,
 
+    /// The awaited duty was evicted before its unsigned data became
+    /// available. Distinct from `Shutdown` so callers can map this to a
+    /// timeout-style error rather than a service-down error.
+    #[error("dutydb: awaited duty expired before data was stored")]
+    AwaitDutyExpired,
+
     /// Two validators share the same `(slot, committee_index, valIdx)` with
     /// different public keys.
     #[error(
@@ -177,6 +183,17 @@ struct ContribKey {
     root: phase0::Root,
 }
 
+/// Per-poll outcome handed back by an `await_data` lookup closure.
+enum Lookup<V> {
+    /// The awaited value is now present — return it to the caller.
+    Found(V),
+    /// The awaited duty has been evicted; the lookup will never succeed.
+    /// `await_data` returns [`Error::AwaitDutyExpired`].
+    Evicted,
+    /// Neither stored nor evicted yet — park on the notify and retry.
+    Pending,
+}
+
 struct State {
     attestation_duties: HashMap<AttKey, phase0::AttestationData>,
     attestation_pub_keys: HashMap<PkKey, PubKey>,
@@ -190,6 +207,27 @@ struct State {
     contrib_duties: HashMap<ContribKey, altair::SyncCommitteeContribution>,
     contrib_keys_by_slot: HashMap<u64, Vec<ContribKey>>,
 
+    /// Highest slot whose attester duty has been evicted by the deadliner.
+    /// Because the deadliner expires duties in non-decreasing slot order and
+    /// `store()` refuses already-expired duties (`AddOutcome::AlreadyExpired`),
+    /// any awaited slot `<=` this mark that is not currently stored will never
+    /// be stored. Tracking only the high-water mark — rather than the set of
+    /// every evicted slot, which would grow without bound for the lifetime of
+    /// the node — lets `await_attestation` return `AwaitDutyExpired`
+    /// immediately for a gone duty while keeping the bookkeeping O(1) in
+    /// memory.
+    max_evicted_attestation_slot: Option<u64>,
+    /// Highest slot whose proposer duty has been evicted. See
+    /// [`max_evicted_attestation_slot`](Self::max_evicted_attestation_slot).
+    max_evicted_proposer_slot: Option<u64>,
+    /// Highest slot whose sync-contribution duty has been evicted. See
+    /// [`max_evicted_attestation_slot`](Self::max_evicted_attestation_slot).
+    max_evicted_contrib_slot: Option<u64>,
+    // NB: there is no eviction mark for aggregated attestations. They are
+    // awaited by root only (`await_agg_attestation` has no slot), so there is
+    // no slot to compare against a high-water mark; an evicted root relies on
+    // the caller's request timeout instead, matching Charon's Go dutydb which
+    // keeps no eviction record at all.
     deadliner_rx: tokio::sync::mpsc::Receiver<Duty>,
 }
 
@@ -225,6 +263,9 @@ impl MemDB {
                 aggregation_keys_by_slot: HashMap::new(),
                 contrib_duties: HashMap::new(),
                 contrib_keys_by_slot: HashMap::new(),
+                max_evicted_attestation_slot: None,
+                max_evicted_proposer_slot: None,
+                max_evicted_contrib_slot: None,
                 deadliner_rx,
             }),
             attestation_notify: Notify::new(),
@@ -272,7 +313,6 @@ impl MemDB {
                     Some(UnsignedDutyData::Proposal(p)) => state.store_proposal(p)?,
                     Some(_) => return Err(Error::InvalidVersionedProposal),
                 }
-                self.proposer_notify.notify_waiters();
             }
             DutyType::Attester => {
                 for (pubkey, data) in &unsigned_set {
@@ -282,7 +322,6 @@ impl MemDB {
                     };
                     state.store_attestation(*pubkey, att)?;
                 }
-                self.attestation_notify.notify_waiters();
             }
             DutyType::Aggregator => {
                 for data in unsigned_set.values() {
@@ -292,7 +331,6 @@ impl MemDB {
                     };
                     state.store_agg_attestation(agg)?;
                 }
-                self.aggregation_notify.notify_waiters();
             }
             DutyType::SyncContribution => {
                 for data in unsigned_set.values() {
@@ -302,24 +340,54 @@ impl MemDB {
                     };
                     state.store_sync_contribution(contrib)?;
                 }
-                self.contrib_notify.notify_waiters();
             }
             _ => return Err(Error::UnsupportedDutyType),
         }
-
-        // Drain all expired duties that the deadliner has sent.
+        // Wake the matching notify for the duty we just stored, plus
+        // anything we drain below. `notify_waiters` is cheap if no one is
+        // parked and just bumps a counter, so calling it under the write
+        // lock is harmless — woken tasks block on `state.read()` until we
+        // drop.
+        self.wake(duty.duty_type);
+
+        // Drain all expired duties that the deadliner has sent. Waiters
+        // whose duty just expired need to see `Lookup::Evicted` and exit,
+        // not re-park — so we wake the matching notify after each eviction.
         while let Ok(expired) = state.deadliner_rx.try_recv() {
+            let duty_type = expired.duty_type.clone();
             state.delete_duty(expired)?;
+            self.wake(duty_type);
         }
 
         Ok(())
     }
 
+    /// Wakes the [`Notify`] paired with `duty_type`. No-op for duty types
+    /// the DB doesn't track (e.g. `Exit`, `BuilderRegistration`).
+    fn wake(&self, duty_type: DutyType) {
+        let notify = match duty_type {
+            DutyType::Proposer => &self.proposer_notify,
+            DutyType::Attester => &self.attestation_notify,
+            DutyType::Aggregator => &self.aggregation_notify,
+            DutyType::SyncContribution => &self.contrib_notify,
+            _ => return,
+        };
+        notify.notify_waiters();
+    }
+
     /// Blocks until a proposal for the given slot is available, then returns
     /// it.
     pub async fn await_proposal(&self, slot: u64) -> Result<VersionedProposal> {
-        self.await_data(&self.proposer_notify, |s| s.proposer_duties.get(&slot))
-            .await
+        self.await_data(&self.proposer_notify, |s| {
+            if let Some(v) = s.proposer_duties.get(&slot) {
+                Lookup::Found(v.clone())
+            } else if s.max_evicted_proposer_slot.is_some_and(|hw| slot <= hw) {
+                Lookup::Evicted
+            } else {
+                Lookup::Pending
+            }
+        })
+        .await
     }
 
     /// Blocks until attestation data for the given slot and committee index is
@@ -333,8 +401,19 @@ impl MemDB {
             slot,
             committee_index,
         };
-        self.await_data(&self.attestation_notify, |s| s.attestation_duties.get(&key))
-            .await
+        self.await_data(&self.attestation_notify, |s| {
+            if let Some(v) = s.attestation_duties.get(&key) {
+                Lookup::Found(v.clone())
+            } else if s
+                .max_evicted_attestation_slot
+                .is_some_and(|hw| key.slot <= hw)
+            {
+                Lookup::Evicted
+            } else {
+                Lookup::Pending
+            }
+        })
+        .await
     }
 
     /// Blocks until an aggregated attestation for the given slot and
@@ -347,7 +426,14 @@ impl MemDB {
             root: attestation_root,
         };
         self.await_data(&self.aggregation_notify, |s| {
-            s.aggregation_duties.get(&key).map(|a| &a.0)
+            // Awaited by root only, so there is no slot to test against an
+            // eviction high-water mark: an evicted root relies on the caller's
+            // request timeout to terminate (matching Charon's Go dutydb).
+            if let Some(v) = s.aggregation_duties.get(&key) {
+                Lookup::Found(v.0.clone())
+            } else {
+                Lookup::Pending
+            }
         })
         .await
     }
@@ -365,31 +451,43 @@ impl MemDB {
             subcommittee_index,
             root: beacon_block_root,
         };
-        self.await_data(&self.contrib_notify, |s| s.contrib_duties.get(&key))
-            .await
+        self.await_data(&self.contrib_notify, |s| {
+            if let Some(v) = s.contrib_duties.get(&key) {
+                Lookup::Found(v.clone())
+            } else if s.max_evicted_contrib_slot.is_some_and(|hw| slot <= hw) {
+                Lookup::Evicted
+            } else {
+                Lookup::Pending
+            }
+        })
+        .await
     }
 
     // A single Notify per duty type wakes all waiters on every store, not only
     // those whose key matches. The number of concurrent waiters per duty type
     // is small (one per validator), so the extra wakeups are cheap. A keyed
     // notify (HashMap<Key, Sender>) would avoid them but adds complexity that
     // isn't worth it here.
+    //
+    // `delete_duty` also wakes the notify so waiters whose duty just expired
+    // exit immediately via the `Lookup::Evicted` branch, instead of parking
+    // for another `notify_waiters` call or for the per-request timeout in
+    // the caller.
     async fn await_data<V>(
         &self,
         notify: &Notify,
-        lookup: impl for<'s> Fn(&'s State) -> Option<&'s V>,
-    ) -> Result<V>
-    where
-        V: Clone,
-    {
+        lookup: impl Fn(&State) -> Lookup<V>,
+    ) -> Result<V> {
         loop {
             let notified = notify.notified();
             tokio::pin!(notified);
 
             {
                 let state = self.state.read().await;
-                if let Some(v) = lookup(&state) {
-                    return Ok(v.clone());
+                match lookup(&state) {
+                    Lookup::Found(v) => return Ok(v),
+                    Lookup::Evicted => return Err(Error::AwaitDutyExpired),
+                    Lookup::Pending => {}
                 }
             }
 
@@ -571,12 +669,20 @@ impl State {
         Ok(())
     }
 
+    /// Raises an eviction high-water mark to `slot` if `slot` is newer (or the
+    /// mark is unset). The deadliner expires duties in non-decreasing slot
+    /// order, so in practice this only ever moves the mark forward.
+    fn bump_high_water(mark: &mut Option<u64>, slot: u64) {
+        *mark = Some(mark.map_or(slot, |current| current.max(slot)));
+    }
+
     fn delete_duty(&mut self, duty: Duty) -> Result<()> {
         let slot = duty.slot.inner();
         info!(slot, duty_type = %duty.duty_type, "dutydb: deleting expired duty");
         match duty.duty_type {
             DutyType::Proposer => {
                 self.proposer_duties.remove(&slot);
+                Self::bump_high_water(&mut self.max_evicted_proposer_slot, slot);
             }
             DutyType::BuilderProposer => return Err(Error::DeprecatedDutyBuilderProposer),
             DutyType::Attester => {
@@ -589,8 +695,11 @@ impl State {
                         });
                     }
                 }
+                Self::bump_high_water(&mut self.max_evicted_attestation_slot, slot);
             }
             DutyType::Aggregator => {
+                // No eviction mark: aggregated attestations are awaited by root
+                // only, so there is nothing for a slot high-water mark to gate.
                 if let Some(keys) = self.aggregation_keys_by_slot.remove(&slot) {
                     for key in keys {
                         self.aggregation_duties.remove(&key);
@@ -603,6 +712,7 @@ impl State {
                         self.contrib_duties.remove(&key);
                     }
                 }
+                Self::bump_high_water(&mut self.max_evicted_contrib_slot, slot);
             }
             _ => return Err(Error::UnknownDutyType),
         }
@@ -1166,6 +1276,67 @@ mod tests {
         assert!(db.pub_key_by_attestation(SLOT, 0, 0).await.is_err());
     }
 
+    /// After a slot is evicted, `await_attestation` must return
+    /// `AwaitDutyExpired` immediately (not park until the request timeout) for
+    /// that slot AND for any older slot — the eviction state is a single
+    /// high-water mark, so it stays O(1) in memory rather than accumulating one
+    /// entry per evicted slot for the lifetime of the node.
+    #[tokio::test]
+    async fn await_attestation_expired_after_eviction_high_water() {
+        let deadliner = far_future_handle();
+        let (trim_tx, trim_rx) = channel::<Duty>(64);
+        let db = make_db_with_deadliner(deadliner, trim_rx);
+
+        const SLOT: u64 = 123;
+
+        let mut set = UnsignedDataSet::new();
+        set.insert(
+            random_core_pub_key(),
+            UnsignedDutyData::Attestation(att_data(SLOT, 0, 0)),
+        );
+        db.store(Duty::new(SlotNumber::new(SLOT), DutyType::Attester), set)
+            .await
+            .unwrap();
+
+        // Evict SLOT, then trigger expiry processing with an unrelated store.
+        trim_tx
+            .send(Duty::new(SlotNumber::new(SLOT), DutyType::Attester))
+            .await
+            .expect("trim_tx should be open");
+        let mut set2 = UnsignedDataSet::new();
+        set2.insert(
+            random_core_pub_key(),
+            UnsignedDutyData::Proposal(Box::new(phase0_proposal(SLOT.saturating_add(1), 0))),
+        );
+        db.store(
+            Duty::new(SlotNumber::new(SLOT.saturating_add(1)), DutyType::Proposer),
+            set2,
+        )
+        .await
+        .unwrap();
+
+        // The evicted slot resolves to AwaitDutyExpired without parking.
+        let timeout = std::time::Duration::from_secs(5);
+        let evicted = tokio::time::timeout(timeout, db.await_attestation(SLOT, 0))
+            .await
+            .expect("await must not park for an evicted slot");
+        assert!(
+            matches!(evicted, Err(Error::AwaitDutyExpired)),
+            "evicted slot: expected AwaitDutyExpired, got {evicted:?}"
+        );
+
+        // An older, never-stored slot is also below the high-water mark: its
+        // deadline has necessarily passed too, so it must fail fast rather than
+        // park — and we keep no per-slot record to answer this.
+        let older = tokio::time::timeout(timeout, db.await_attestation(SLOT.saturating_sub(1), 0))
+            .await
+            .expect("await must not park for a slot below the eviction high-water");
+        assert!(
+            matches!(older, Err(Error::AwaitDutyExpired)),
+            "older slot: expected AwaitDutyExpired, got {older:?}"
+        );
+    }
+
     #[tokio::test]
     async fn agg_attestation_two_roots_same_slot() {
         const SLOT: u64 = 300;