Use async queryRandom instead of inefficient randomNodes to discover nodes (#2211)

beacon_chain/eth2_discovery.nim

@@ -14,7 +14,7 @@ type
   PublicKey = keys.PublicKey
 
 export
-  Eth2DiscoveryProtocol, open, start, close, closeWait, randomNodes,
+  Eth2DiscoveryProtocol, open, start, close, closeWait, queryRandom,
     updateRecord, results
 
 proc parseBootstrapAddress*(address: TaintedString):

beacon_chain/eth2_network.nim

@@ -875,10 +875,8 @@ proc runDiscoveryLoop*(node: Eth2Node) {.async.} =
   let enrField = ("eth2", SSZ.encode(node.forkId))
 
   while true:
-    # We always request constant number of peers to avoid problem with
-    # low amount of returned peers.
-    let discoveredNodes = node.discovery.randomNodes(node.wantedPeers, enrField)
-
+    if node.peerPool.lenSpace({PeerType.Outgoing}) > 0:
+      var discoveredNodes = await node.discovery.queryRandom(enrField)
       var newPeers = 0
       for discNode in discoveredNodes:
         let res = discNode.toPeerAddr()
@@ -902,7 +900,7 @@ proc runDiscoveryLoop*(node: Eth2Node) {.async.} =
           debug "Failed to decode discovery's node address",
                 node = discnode, errMsg = res.error
 
-    trace "Discovery tick", wanted_peers = node.wantedPeers,
+      debug "Discovery tick", wanted_peers = node.wantedPeers,
             space = node.peerPool.shortLogSpace(),
             acquired = node.peerPool.shortLogAcquired(),
             available = node.peerPool.shortLogAvailable(),
@@ -914,14 +912,9 @@ proc runDiscoveryLoop*(node: Eth2Node) {.async.} =
       if newPeers == 0:
         let currentPeers = node.peerPool.lenCurrent()
         if currentPeers <= node.wantedPeers shr 2: #  25%
-        notice "Peer count low, no new peers discovered",
-          discovered = len(discoveredNodes), new_peers = newPeers,
-          current_peers = currentPeers, wanted_peers = node.wantedPeers
-      elif currentPeers <= node.wantedPeers shr 3: # 12.5 %
           warn "Peer count low, no new peers discovered",
-          discovered = len(discoveredNodes), new_peers = newPeers,
+            discovered_nodes = len(discoveredNodes), new_peers = newPeers,
             current_peers = currentPeers, wanted_peers = node.wantedPeers
-      await sleepAsync(5.seconds)
     else:
       await sleepAsync(1.seconds)
 

vendor/nim-eth

@@ -1 +1 @@
-Subproject commit 8de6bd4f48ee6a0bca8dc3905cf68b4cc29a96d6
+Subproject commit e25500c9f0597e91979a4c714989abd6e01f70d9