[Fix] Propagation improvements (#784)

Author: Nicolás Tallar

src/main/resources/application.conf

@@ -119,13 +119,13 @@ mantis {
       max-mpt-components-per-message = 200
 
       # Maximum number of peers this node can connect to
-      max-outgoing-peers = 80
+      max-outgoing-peers = 45
 
       # Maximum number of peers that can connect to this node
-      max-incoming-peers = 5
+      max-incoming-peers = 15
 
       # Maximum number of peers that can be connecting to this node
-      max-pending-peers = 5
+      max-pending-peers = 20
 
       # Initial delay before connecting to nodes
       update-nodes-initial-delay = 5.seconds
@@ -343,9 +343,7 @@ mantis {
 
     # When we receive a branch that is not rooted in our chain (we don't have a parent for the first header), it means
     # we found a fork. To resolve it, we need to query the same peer for previous headers, to find a common ancestor.
-    # This setting determines how many additional headers we request. The default of 12 may be regarded as confirmation
-    # depth in ethereum (https://www.reddit.com/r/ethereum/comments/4eplsv/how_many_confirms_is_considered_safe_in_ethereum/)
-    branch-resolution-request-size = 12
+    branch-resolution-request-size = 30
 
     # TODO investigate proper value to handle ETC reorgs correctly
     # threshold for storing non-main-chain blocks in queue.

src/main/resources/chains/testnet-internal-genesis.json

@@ -2,9 +2,11 @@
   "extraData": "0x00",
   "nonce": "0x0000000000000042",
   "gasLimit": "0x2fefd8",
-  "difficulty": "0x400",
+  "_commentAboutDifficulty": "Set to 1000000",
+  "difficulty": "0xF4240",
   "ommersHash": "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
-  "timestamp": "0x00",
+  "_commentAboutTimestamp": "Set to 11/05/2020 @ 12:00am (UTC)",
+  "timestamp": "0x5FA34080",
   "coinbase": "0x0000000000000000000000000000000000000000",
   "mixHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
   "alloc": {

src/main/scala/io/iohk/ethereum/blockchain/sync/regular/BlockFetcher.scala

@@ -184,7 +184,7 @@ class BlockFetcher(
   private def handleNewBlockMessages(state: BlockFetcherState): Receive = {
     case MessageFromPeer(NewBlockHashes(hashes), _) =>
       log.debug("Received NewBlockHashes numbers {}", hashes.map(_.number).mkString(", "))
-      val newState = state.validatedHashes(hashes) match {
+      val newState = state.validateNewBlockHashes(hashes) match {
         case Left(_) => state
         case Right(validHashes) => state.withPossibleNewTopAt(validHashes.lastOption.map(_.number))
       }

src/main/scala/io/iohk/ethereum/blockchain/sync/regular/BlockFetcherState.scala

@@ -90,11 +90,10 @@ case class BlockFetcherState(
         .ensure("Given headers should form a sequence without gaps")(HeadersSeq.areChain)
     }
 
-  def validatedHashes(hashes: Seq[BlockHash]): Either[String, Seq[BlockHash]] =
+  def validateNewBlockHashes(hashes: Seq[BlockHash]): Either[String, Seq[BlockHash]] =
     hashes
       .asRight[String]
       .ensure("Hashes are empty")(_.nonEmpty)
-      .ensure("Hashes are too new")(_.head.number == nextToLastBlock)
       .ensure("Hashes should form a chain")(hashes =>
         hashes.zip(hashes.tail).forall { case (a, b) =>
           a.number + 1 == b.number