Sync update (#1412)

## Issue Addressed

Recurring sync loop and invalid batch downloading

## Proposed Changes

Shifts the batches to include the first slot of each epoch. This ensures the finalized is always downloaded once a chain has completed syncing. 

Also add in logic to prevent re-dialing disconnected peers. Non-performant peers get disconnected during sync, this prevents re-connection to these during sync. 

## Additional Info

N/A

beacon_node/eth2_libp2p/src/peer_manager/mod.rs

@@ -159,7 +159,7 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
             info.score.apply_peer_action(action);
             if previous_state != info.score.state() {
                 match info.score.state() {
-                    ScoreState::Ban => {
+                    ScoreState::Banned => {
                         debug!(self.log, "Peer has been banned"; "peer_id" => peer_id.to_string(), "score" => info.score.to_string());
                         ban_peer = Some(peer_id.clone());
                         if info.connection_status.is_connected_or_dialing() {
@@ -169,7 +169,7 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
                             ));
                         }
                     }
-                    ScoreState::Disconnect => {
+                    ScoreState::Disconnected => {
                         debug!(self.log, "Peer transitioned to disconnect state"; "peer_id" => peer_id.to_string(), "score" => info.score.to_string(), "past_state" => previous_state.to_string());
                         // disconnect the peer if it's currently connected or dialing
                         unban_peer = Some(peer_id.clone());
@@ -501,7 +501,11 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
                     .peers
                     .read()
                     .is_connected_or_dialing(&peer_id)
-                && !self.network_globals.peers.read().is_banned(&peer_id)
+                && !self
+                    .network_globals
+                    .peers
+                    .read()
+                    .is_banned_or_disconnected(&peer_id)
             {
                 // TODO: Update output
                 // This should be updated with the peer dialing. In fact created once the peer is
@@ -629,7 +633,7 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
             // handle score transitions
             if previous_state != info.score.state() {
                 match info.score.state() {
-                    ScoreState::Ban => {
+                    ScoreState::Banned => {
                         debug!(self.log, "Peer has been banned"; "peer_id" => peer_id.to_string(), "score" => info.score.to_string());
                         to_ban_peers.push(peer_id.clone());
                         if info.connection_status.is_connected_or_dialing() {
@@ -639,7 +643,7 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
                             ));
                         }
                     }
-                    ScoreState::Disconnect => {
+                    ScoreState::Disconnected => {
                         debug!(self.log, "Peer transitioned to disconnect state"; "peer_id" => peer_id.to_string(), "score" => info.score.to_string(), "past_state" => previous_state.to_string());
                         // disconnect the peer if it's currently connected or dialing
                         to_unban_peers.push(peer_id.clone());

beacon_node/eth2_libp2p/src/peer_manager/peerdb.rs

@@ -1,6 +1,6 @@
 use super::peer_info::{PeerConnectionStatus, PeerInfo};
 use super::peer_sync_status::PeerSyncStatus;
-use super::score::Score;
+use super::score::{Score, ScoreState};
 use crate::rpc::methods::MetaData;
 use crate::PeerId;
 use rand::seq::SliceRandom;
@@ -99,9 +99,17 @@ impl<TSpec: EthSpec> PeerDB<TSpec> {
 
     /// Returns true if the Peer is banned.
     pub fn is_banned(&self, peer_id: &PeerId) -> bool {
-        match self.peers.get(peer_id).map(|info| &info.connection_status) {
-            Some(status) => status.is_banned(),
-            None => false,
+        match self.peers.get(peer_id).map(|info| info.score.state()) {
+            Some(ScoreState::Banned) => true,
+            _ => false,
+        }
+    }
+
+    /// Returns true if the Peer is either banned or in the disconnected state.
+    pub fn is_banned_or_disconnected(&self, peer_id: &PeerId) -> bool {
+        match self.peers.get(peer_id).map(|info| info.score.state()) {
+            Some(ScoreState::Banned) | Some(ScoreState::Disconnected) => true,
+            _ => false,
         }
     }
 

beacon_node/eth2_libp2p/src/peer_manager/score.rs

@@ -60,10 +60,10 @@ pub(crate) enum ScoreState {
     /// We are content with the peers performance. We permit connections and messages.
     Healthy,
     /// The peer should be disconnected. We allow re-connections if the peer is persistent.
-    Disconnect,
+    Disconnected,
     /// The peer is banned. We disallow new connections until it's score has decayed into a
     /// tolerable threshold.
-    Ban,
+    Banned,
 }
 
 /// A peer's score (perceived potential usefulness).
@@ -138,8 +138,8 @@ impl std::fmt::Display for ScoreState {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             ScoreState::Healthy => write!(f, "Healthy"),
-            ScoreState::Ban => write!(f, "Ban"),
-            ScoreState::Disconnect => write!(f, "Disconnect"),
+            ScoreState::Banned => write!(f, "Banned"),
+            ScoreState::Disconnected => write!(f, "Disconnected"),
         }
     }
 }
@@ -164,8 +164,8 @@ impl Score {
     /// Returns the expected state of the peer given it's score.
     pub(crate) fn state(&self) -> ScoreState {
         match self.score {
-            x if x <= MIN_SCORE_BEFORE_BAN => ScoreState::Ban,
-            x if x <= MIN_SCORE_BEFORE_DISCONNECT => ScoreState::Disconnect,
+            x if x <= MIN_SCORE_BEFORE_BAN => ScoreState::Banned,
+            x if x <= MIN_SCORE_BEFORE_DISCONNECT => ScoreState::Disconnected,
             _ => ScoreState::Healthy,
         }
     }