Fix subscribing to attestation subnets for aggregating (sigp#6681)

* Prevent scheduled subnet subscriptions from being overwritten by other subscriptions from same subnet with additional scoping by slot

Author: povi

beacon_node/network/src/subnet_service/mod.rs

@@ -86,7 +86,7 @@ pub struct SubnetService<T: BeaconChainTypes> {
     subscriptions: HashSetDelay<Subnet>,
 
     /// Subscriptions that need to be executed in the future.
-    scheduled_subscriptions: HashSetDelay<Subnet>,
+    scheduled_subscriptions: HashSetDelay<ExactSubnet>,
 
     /// A list of permanent subnets that this node is subscribed to.
     // TODO: Shift this to a dynamic bitfield
@@ -485,7 +485,7 @@ impl<T: BeaconChainTypes> SubnetService<T> {
         } else {
             // This is a future slot, schedule subscribing.
             self.scheduled_subscriptions
-                .insert_at(subnet, time_to_subscription_start);
+                .insert_at(ExactSubnet { subnet, slot }, time_to_subscription_start);
         }
 
         Ok(())
@@ -626,7 +626,8 @@ impl<T: BeaconChainTypes> Stream for SubnetService<T> {
         // Process scheduled subscriptions that might be ready, since those can extend a soon to
         // expire subscription.
         match self.scheduled_subscriptions.poll_next_unpin(cx) {
-            Poll::Ready(Some(Ok(subnet))) => {
+            Poll::Ready(Some(Ok(exact_subnet))) => {
+                let ExactSubnet { subnet, .. } = exact_subnet;
                 let current_slot = self.beacon_chain.slot_clock.now().unwrap_or_default();
                 if let Err(e) = self.subscribe_to_subnet_immediately(subnet, current_slot + 1) {
                     debug!(self.log, "Failed to subscribe to short lived subnet"; "subnet" => ?subnet, "err" => e);

beacon_node/network/src/subnet_service/tests/mod.rs

@@ -500,12 +500,15 @@ mod test {
         // subscription config
         let committee_count = 1;
 
-        // Makes 2 validator subscriptions to the same subnet but at different slots.
-        // There should be just 1 unsubscription event for the later slot subscription (subscription_slot2).
+        // Makes 3 validator subscriptions to the same subnet but at different slots.
+        // There should be just 1 unsubscription event for each of the later slots subscriptions
+        // (subscription_slot2 and subscription_slot3).
         let subscription_slot1 = 0;
         let subscription_slot2 = MIN_PEER_DISCOVERY_SLOT_LOOK_AHEAD + 4;
+        let subscription_slot3 = subscription_slot2 * 2;
         let com1 = MIN_PEER_DISCOVERY_SLOT_LOOK_AHEAD + 4;
         let com2 = 0;
+        let com3 = CHAIN.chain.spec.attestation_subnet_count - com1;
 
         // create the attestation service and subscriptions
         let mut subnet_service = get_subnet_service();
@@ -532,6 +535,13 @@ mod test {
             true,
         );
 
+        let sub3 = get_subscription(
+            com3,
+            current_slot + Slot::new(subscription_slot3),
+            committee_count,
+            true,
+        );
+
         let subnet_id1 = SubnetId::compute_subnet::<MainnetEthSpec>(
             current_slot + Slot::new(subscription_slot1),
             com1,
@@ -548,12 +558,23 @@ mod test {
         )
         .unwrap();
 
+        let subnet_id3 = SubnetId::compute_subnet::<MainnetEthSpec>(
+            current_slot + Slot::new(subscription_slot3),
+            com3,
+            committee_count,
+            &subnet_service.beacon_chain.spec,
+        )
+        .unwrap();
+
         // Assert that subscriptions are different but their subnet is the same
         assert_ne!(sub1, sub2);
+        assert_ne!(sub1, sub3);
+        assert_ne!(sub2, sub3);
         assert_eq!(subnet_id1, subnet_id2);
+        assert_eq!(subnet_id1, subnet_id3);
 
         // submit the subscriptions
-        subnet_service.validator_subscriptions(vec![sub1, sub2].into_iter());
+        subnet_service.validator_subscriptions(vec![sub1, sub2, sub3].into_iter());
 
         // Unsubscription event should happen at the end of the slot.
         // We wait for 2 slots, to avoid timeout issues
@@ -590,10 +611,36 @@ mod test {
         // If the permanent and short lived subnets are different, we should get an unsubscription event.
         if !subnet_service.is_subscribed(&Subnet::Attestation(subnet_id1)) {
             assert_eq!(
-                [expected_subscription, expected_unsubscription],
+                [
+                    expected_subscription.clone(),
+                    expected_unsubscription.clone(),
+                ],
                 second_subscribe_event[..]
             );
         }
+
+        let subscription_slot = current_slot + subscription_slot3 - 1;
+
+        let wait_slots = subnet_service
+            .beacon_chain
+            .slot_clock
+            .duration_to_slot(subscription_slot)
+            .unwrap()
+            .as_millis() as u64
+            / SLOT_DURATION_MILLIS;
+
+        let no_events = dbg!(get_events(&mut subnet_service, None, wait_slots as u32).await);
+
+        assert_eq!(no_events, []);
+
+        let third_subscribe_event = get_events(&mut subnet_service, None, 2).await;
+
+        if !subnet_service.is_subscribed(&Subnet::Attestation(subnet_id1)) {
+            assert_eq!(
+                [expected_subscription, expected_unsubscription],
+                third_subscribe_event[..]
+            );
+        }
     }
 
     #[tokio::test]