From 0bb5ab82a95551fb6773a7233c306b1c07ef04ed Mon Sep 17 00:00:00 2001
From: pawan <pawandhananjay@gmail.com>
Date: Tue, 21 Jul 2020 18:52:02 +0530
Subject: [PATCH] Dial cached enrs before queueing subnet query

---
 beacon_node/eth2_libp2p/src/discovery/mod.rs  |  2 +-
 .../eth2_libp2p/src/peer_manager/mod.rs       | 29 ++++++++++++++-----
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/beacon_node/eth2_libp2p/src/discovery/mod.rs b/beacon_node/eth2_libp2p/src/discovery/mod.rs
index 0624414c5dd..2bcc3caa560 100644
--- a/beacon_node/eth2_libp2p/src/discovery/mod.rs
+++ b/beacon_node/eth2_libp2p/src/discovery/mod.rs
@@ -476,7 +476,7 @@ impl<TSpec: EthSpec> Discovery<TSpec> {
             .peers_on_subnet(subnet_id)
             .count();
 
-        if peers_on_subnet > TARGET_SUBNET_PEERS {
+        if peers_on_subnet >= TARGET_SUBNET_PEERS {
             debug!(self.log, "Discovery ignored";
                 "reason" => "Already connected to desired peers",
                 "connected_peers_on_subnet" => peers_on_subnet,
diff --git a/beacon_node/eth2_libp2p/src/peer_manager/mod.rs b/beacon_node/eth2_libp2p/src/peer_manager/mod.rs
index fa7c2524ade..dfbde42883f 100644
--- a/beacon_node/eth2_libp2p/src/peer_manager/mod.rs
+++ b/beacon_node/eth2_libp2p/src/peer_manager/mod.rs
@@ -215,18 +215,26 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
                 .extend_peers_on_subnet(subnet_id, min_ttl);
         }
 
-        // Attempt to connect to cached_enr's satisfying subnet predicate
-        let predicate = subnet_predicate::<TSpec>(subnet_id, &self.log);
-        let mut connected = self
+        let mut peers_on_subnet = self
             .network_globals
             .peers
             .read()
             .peers_on_subnet(subnet_id)
             .count();
 
-        if connected > TARGET_SUBNET_PEERS {
+        // Check if we already have required number of peers on the subnet
+        if peers_on_subnet >= TARGET_SUBNET_PEERS {
+            debug!(self.log, "Discovery ignored";
+                "reason" => "Already connected to desired peers",
+                "connected_peers_on_subnet" => peers_on_subnet,
+                "target_subnet_peers" => TARGET_SUBNET_PEERS,
+            );
             return;
         }
+
+        // Attempt to connect to cached_enr's satisfying subnet predicate
+        let predicate = subnet_predicate::<TSpec>(subnet_id, &self.log);
+
         let subnet_peers: Vec<PeerId> = self
             .discovery
             .cached_enrs()
@@ -239,12 +247,19 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
                 }
             })
             .collect();
-        for peer in subnet_peers {
-            if self.dial_peer(&peer) {
-                connected += 1;
+        for peer_id in subnet_peers {
+            if let Some(min_ttl) = min_ttl {
+                self.network_globals
+                    .peers
+                    .write()
+                    .update_min_ttl(&peer_id, min_ttl);
+            }
+            if self.dial_peer(&peer_id) {
+                peers_on_subnet += 1;
             }
         }
         // request the subnet query from discovery
+        // if we found enough peers from the cached_enrs, we won't need to make a subnet query
         self.discovery.discover_subnet_peers(subnet_id, min_ttl);
     }