From 0ad0cd5e0a85a546087633ba942c6f8c50444c4b Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Wed, 10 Feb 2021 20:28:04 +0100
Subject: [PATCH 01/15] First draft of cache-based blacklist

---
 build.sbt                                     |  1 +
 project/Dependencies.scala                    |  7 ++-
 .../ethereum/blockchain/sync/Blacklist.scala  | 47 ++++++++++++++
 .../blockchain/sync/PeerListSupportNg.scala   | 63 +++++++++++++++++++
 .../blockchain/sync/SyncController.scala      |  4 ++
 .../blockchain/sync/fast/FastSync.scala       | 39 ++++++------
 6 files changed, 142 insertions(+), 19 deletions(-)
 create mode 100644 src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
 create mode 100644 src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala

diff --git a/build.sbt b/build.sbt
index 5fc5d9550c..475eedebf9 100644
--- a/build.sbt
+++ b/build.sbt
@@ -128,6 +128,7 @@ lazy val node = {
       Dependencies.kamon,
       Dependencies.prometheus,
       Dependencies.cli,
+      Dependencies.scaffeine,
       Dependencies.dependencies
     ).flatten ++ malletDeps
   }
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 7b165ae0b1..020e8561b8 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -137,7 +137,7 @@ object Dependencies {
       "com.google.code.findbugs" % "jsr305" % "3.0.2" % Optional,
       provider % "micrometer-core" % version,
       provider % "micrometer-registry-jmx" % version,
-      provider % "micrometer-registry-prometheus" % version,
+      provider % "micrometer-registry-prometheus" % version
     )
   }
 
@@ -153,4 +153,9 @@ object Dependencies {
   val shapeless: Seq[ModuleID] = Seq(
     "com.chuusai" %% "shapeless" % "2.3.3"
   )
+
+  val scaffeine: Seq[ModuleID] = Seq(
+    "com.github.blemale" %% "scaffeine" % "4.0.2" % "compile"
+  )
+
 }
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
new file mode 100644
index 0000000000..defa67bd90
--- /dev/null
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
@@ -0,0 +1,47 @@
+package io.iohk.ethereum.blockchain.sync
+
+import com.github.blemale.scaffeine.{Cache, Scaffeine}
+import io.iohk.ethereum.blockchain.sync.BlacklistSupport.BlackListId
+import io.iohk.ethereum.utils.Logger
+
+import scala.concurrent.duration.FiniteDuration
+
+import scala.jdk.CollectionConverters._
+import scala.jdk.OptionConverters._
+import scala.jdk.DurationConverters._
+
+trait Blacklist {
+  def isBlacklisted(id: BlackListId): Boolean
+  def add(id: BlackListId, duration: FiniteDuration, reason: String): Unit
+  def remove(id: BlackListId): Unit
+  def keys: Set[BlackListId]
+}
+
+final case class CacheBasedBlacklist(cache: Cache[BlackListId, String])
+    extends Blacklist with Logger {
+
+  override def isBlacklisted(id: BlackListId): Boolean = cache.getIfPresent(id).isDefined
+  override def add(id: BlackListId, duration: FiniteDuration, reason: String): Unit =
+    cache.policy().expireVariably().toScala.fold {
+      log.warn(s"Unexpected error while adding peer [$id] to blacklist using custom expiration time. Falling back to default expiration.")
+      cache.put(id, reason)
+    } { ve =>
+      ve.put(id, reason, duration.toJava)
+    }
+  override def remove(id: BlackListId): Unit = cache.invalidate(id)
+
+  override def keys: Set[BlackListId] = cache.underlying.asMap().keySet().asScala.toSet
+}
+
+object CacheBasedBlacklist {
+
+  // TODO check eviction strategy - we want to remove the oldest element if maxSize is reached
+  def empty(maxSize: Int): CacheBasedBlacklist = {
+    val cache =
+      Scaffeine()
+        .maximumSize(maxSize)
+        .build[BlackListId, String]()
+    CacheBasedBlacklist(cache)
+  }
+
+}
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala
new file mode 100644
index 0000000000..1666da3432
--- /dev/null
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala
@@ -0,0 +1,63 @@
+package io.iohk.ethereum.blockchain.sync
+
+import akka.actor.{Actor, ActorLogging, ActorRef, Scheduler}
+import io.iohk.ethereum.network.EtcPeerManagerActor.PeerInfo
+import io.iohk.ethereum.network.PeerEventBusActor.PeerEvent.PeerDisconnected
+import io.iohk.ethereum.network.PeerEventBusActor.SubscriptionClassifier.PeerDisconnectedClassifier
+import io.iohk.ethereum.network.PeerEventBusActor.{PeerSelector, Subscribe, Unsubscribe}
+import io.iohk.ethereum.network.{EtcPeerManagerActor, Peer, PeerId}
+import io.iohk.ethereum.utils.Config.SyncConfig
+
+import scala.concurrent.duration._
+import scala.concurrent.ExecutionContext.Implicits.global // FIXME copied from current impl but not sure global EC is a good choice
+
+trait PeerListSupportNg {
+  self: Actor with ActorLogging =>
+  import PeerListSupportNg._
+
+  def etcPeerManager: ActorRef
+  def peerEventBus: ActorRef
+  def blacklist: Blacklist
+  def syncConfig: SyncConfig
+  def scheduler: Scheduler
+
+  var handshakedPeers: PeersMap = Map.empty
+
+  scheduler.scheduleWithFixedDelay(
+    0.seconds,
+    syncConfig.peersScanInterval,
+    etcPeerManager,
+    EtcPeerManagerActor.GetHandshakedPeers
+  )(global, context.self)
+
+  def removePeer(peerId: PeerId): Unit = {
+    peerEventBus ! Unsubscribe(PeerDisconnectedClassifier(PeerSelector.WithId(peerId)))
+    handshakedPeers.find(_._1.id == peerId).foreach { case (peer, _) => blacklist.remove(peer.id) }
+    handshakedPeers = handshakedPeers.filterNot(_._1.id == peerId)
+  }
+
+  def peersToDownloadFrom: PeersMap =
+    handshakedPeers.filterNot { case (p, _) => blacklist.isBlacklisted(p.id) }
+
+  def handlePeerListMessages: Receive = {
+    case EtcPeerManagerActor.HandshakedPeers(peers) =>
+      peers.keys.filterNot(handshakedPeers.contains).foreach { peer =>
+        peerEventBus ! Subscribe(PeerDisconnectedClassifier(PeerSelector.WithId(peer.id)))
+      }
+      handshakedPeers = peers
+
+    case PeerDisconnected(peerId) if handshakedPeers.exists(_._1.id == peerId) =>
+      removePeer(peerId)
+  }
+
+  def peerById(peerId: PeerId): Option[Peer] = handshakedPeers collectFirst {
+    case (peer, _) if peer.id == peerId => peer
+  }
+
+  def blacklistIfHandshaked(peer: Peer, duration: FiniteDuration, reason: String): Unit =
+    handshakedPeers.get(peer).foreach(_ => blacklist.add(peer.id, duration, reason))
+}
+
+object PeerListSupportNg {
+  type PeersMap = Map[Peer, PeerInfo]
+}
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/SyncController.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/SyncController.scala
index 8c53b4df82..5a24db3d91 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/SyncController.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/SyncController.scala
@@ -26,6 +26,9 @@ class SyncController(
 ) extends Actor
     with ActorLogging {
 
+  private val blacklistSize: Int = 100 // TODO move to config
+  private val blacklist: Blacklist = CacheBasedBlacklist.empty(blacklistSize)
+
   def scheduler: Scheduler = externalSchedulerOpt getOrElse context.system.scheduler
 
   override def receive: Receive = idle
@@ -81,6 +84,7 @@ class SyncController(
         validators,
         peerEventBus,
         etcPeerManager,
+        blacklist,
         syncConfig,
         scheduler
       ),
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
index c54c52a0c4..06d5cc1105 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
@@ -42,12 +42,12 @@ class FastSync(
     val validators: Validators,
     val peerEventBus: ActorRef,
     val etcPeerManager: ActorRef,
+    val blacklist: Blacklist,
     val syncConfig: SyncConfig,
     implicit val scheduler: Scheduler
 ) extends Actor
     with ActorLogging
-    with PeerListSupport
-    with BlacklistSupport
+    with PeerListSupportNg
     with ReceiptsValidator
     with SyncBlocksValidator {
 
@@ -58,7 +58,7 @@ class FastSync(
 
   override def receive: Receive = idle
 
-  def handleCommonMessages: Receive = handlePeerListMessages orElse handleBlacklistMessages
+  def handleCommonMessages: Receive = handlePeerListMessages
 
   def idle: Receive = handleCommonMessages orElse {
     case SyncProtocol.Start => start()
@@ -184,7 +184,7 @@ class FastSync(
           )
             handleBlockHeaders(peer, blockHeaders)
           else
-            blacklist(peer.id, blacklistDuration, "wrong blockheaders response (empty or not chain forming)")
+            blacklist.add(peer.id, blacklistDuration, "wrong blockheaders response (empty or not chain forming)")
         }
 
       case ResponseReceived(peer, BlockBodies(blockBodies), timeTaken) =>
@@ -424,7 +424,7 @@ class FastSync(
     }
 
     private def handleRewind(header: BlockHeader, peer: Peer, N: Int, duration: FiniteDuration): Unit = {
-      blacklist(peer.id, duration, "block header validation failed")
+      blacklist.add(peer.id, duration, "block header validation failed")
       if (header.number <= syncState.safeDownloadTarget) {
         discardLastBlocks(header.number, N)
         syncState = syncState.updateDiscardedBlocks(header, N)
@@ -438,7 +438,7 @@ class FastSync(
       }
     }
 
-    private def handleBlockHeaders(peer: Peer, headers: Seq[BlockHeader]) = {
+    private def handleBlockHeaders(peer: Peer, headers: Seq[BlockHeader]): Unit = {
       if (checkHeadersChain(headers)) {
         processHeaders(peer, headers) match {
           case ParentChainWeightNotFound(header) =>
@@ -462,23 +462,23 @@ class FastSync(
             )
         }
       } else {
-        blacklist(peer.id, blacklistDuration, "error in block headers response")
+        blacklist.add(peer.id, blacklistDuration, "error in block headers response")
         processSyncing()
       }
     }
 
-    private def handleBlockBodies(peer: Peer, requestedHashes: Seq[ByteString], blockBodies: Seq[BlockBody]) = {
+    private def handleBlockBodies(peer: Peer, requestedHashes: Seq[ByteString], blockBodies: Seq[BlockBody]): Unit = {
       if (blockBodies.isEmpty) {
         val reason =
           s"got empty block bodies response for known hashes: ${requestedHashes.map(ByteStringUtils.hash2string)}"
-        blacklist(peer.id, blacklistDuration, reason)
+        blacklist.add(peer.id, blacklistDuration, reason)
         syncState = syncState.enqueueBlockBodies(requestedHashes)
       } else {
         validateBlocks(requestedHashes, blockBodies) match {
           case BlockBodyValidationResult.Valid =>
             insertBlocks(requestedHashes, blockBodies)
           case BlockBodyValidationResult.Invalid =>
-            blacklist(
+            blacklist.add(
               peer.id,
               blacklistDuration,
               s"responded with block bodies not matching block headers, blacklisting for $blacklistDuration"
@@ -492,10 +492,10 @@ class FastSync(
       processSyncing()
     }
 
-    private def handleReceipts(peer: Peer, requestedHashes: Seq[ByteString], receipts: Seq[Seq[Receipt]]) = {
+    private def handleReceipts(peer: Peer, requestedHashes: Seq[ByteString], receipts: Seq[Seq[Receipt]]): Unit = {
       if (receipts.isEmpty) {
         val reason = s"got empty receipts for known hashes: ${requestedHashes.map(ByteStringUtils.hash2string)}"
-        blacklist(peer.id, blacklistDuration, reason)
+        blacklist.add(peer.id, blacklistDuration, reason)
         syncState = syncState.enqueueReceipts(requestedHashes)
       } else {
         validateReceipts(requestedHashes, receipts) match {
@@ -519,7 +519,7 @@ class FastSync(
             val reason =
               s"got invalid receipts for known hashes: ${requestedHashes.map(h => Hex.toHexString(h.toArray[Byte]))}" +
                 s" due to: $error"
-            blacklist(peer.id, blacklistDuration, reason)
+            blacklist.add(peer.id, blacklistDuration, reason)
             syncState = syncState.enqueueReceipts(requestedHashes)
 
           case ReceiptsValidationResult.DbError =>
@@ -530,7 +530,7 @@ class FastSync(
       processSyncing()
     }
 
-    private def handleRequestFailure(peer: Peer, handler: ActorRef, reason: String) = {
+    private def handleRequestFailure(peer: Peer, handler: ActorRef, reason: String): Unit = {
       removeRequestHandler(handler)
 
       syncState = syncState
@@ -542,7 +542,7 @@ class FastSync(
 
       requestedHeaders -= peer
       if (handshakedPeers.contains(peer)) {
-        blacklist(peer.id, blacklistDuration, reason)
+        blacklist.add(peer.id, blacklistDuration, reason)
       }
     }
 
@@ -566,17 +566,18 @@ class FastSync(
       )
     }
 
-    private def printStatus() = {
+    private def printStatus(): Unit = {
       val formatPeer: (Peer) => String = peer =>
         s"${peer.remoteAddress.getAddress.getHostAddress}:${peer.remoteAddress.getPort}"
+      val blacklistedIds = blacklist.keys
       log.info(s"""|Block: ${appStateStorage.getBestBlockNumber()}/${syncState.pivotBlock.number}.
-            |Peers waiting_for_response/connected: ${assignedHandlers.size}/${handshakedPeers.size} (${blacklistedPeers.size} blacklisted).
+            |Peers waiting_for_response/connected: ${assignedHandlers.size}/${handshakedPeers.size} (${blacklistedIds.size} blacklisted).
             |State: ${syncState.downloadedNodesCount}/${syncState.totalNodesCount} nodes.
             |""".stripMargin.replace("\n", " "))
       log.debug(
         s"""|Connection status: connected(${assignedHandlers.values.map(formatPeer).toSeq.sorted.mkString(", ")})/
             |handshaked(${handshakedPeers.keys.map(formatPeer).toSeq.sorted.mkString(", ")})
-            | blacklisted(${blacklistedPeers.map { case (id, _) => id.value }.mkString(", ")})
+            | blacklisted(${blacklistedIds.map(_.value)mkString(", ")})
             |""".stripMargin.replace("\n", " ")
       )
     }
@@ -841,6 +842,7 @@ object FastSync {
       validators: Validators,
       peerEventBus: ActorRef,
       etcPeerManager: ActorRef,
+      blacklist: Blacklist,
       syncConfig: SyncConfig,
       scheduler: Scheduler
   ): Props =
@@ -852,6 +854,7 @@ object FastSync {
         validators,
         peerEventBus,
         etcPeerManager,
+        blacklist,
         syncConfig,
         scheduler
       )

From 20b0045b34cc408fdfcb28614e408f73f5272d5e Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Wed, 10 Feb 2021 20:36:04 +0100
Subject: [PATCH 02/15] Fix logging output

---
 .../io/iohk/ethereum/blockchain/sync/fast/FastSync.scala  | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
index 06d5cc1105..b4a788abef 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
@@ -157,7 +157,7 @@ class FastSync(
     def handleStatus: Receive = {
       case SyncProtocol.GetStatus => sender() ! currentSyncingStatus
       case SyncStateSchedulerActor.StateSyncStats(saved, missing) =>
-        syncState = syncState.copy(downloadedNodesCount = saved, totalNodesCount = (saved + missing))
+        syncState = syncState.copy(downloadedNodesCount = saved, totalNodesCount = saved + missing)
     }
 
     def receive: Receive = handleCommonMessages orElse handleStatus orElse {
@@ -507,7 +507,7 @@ class FastSync(
               .reduce(_.and(_))
               .commit()
 
-            val receivedHashes = blockHashesWithReceipts.unzip._1
+            val receivedHashes = blockHashesWithReceipts.map(_._1)
             updateBestBlockIfNeeded(receivedHashes)
 
             val remainingReceipts = requestedHashes.drop(receipts.size)
@@ -567,7 +567,7 @@ class FastSync(
     }
 
     private def printStatus(): Unit = {
-      val formatPeer: (Peer) => String = peer =>
+      val formatPeer: Peer => String = peer =>
         s"${peer.remoteAddress.getAddress.getHostAddress}:${peer.remoteAddress.getPort}"
       val blacklistedIds = blacklist.keys
       log.info(s"""|Block: ${appStateStorage.getBestBlockNumber()}/${syncState.pivotBlock.number}.
@@ -577,7 +577,7 @@ class FastSync(
       log.debug(
         s"""|Connection status: connected(${assignedHandlers.values.map(formatPeer).toSeq.sorted.mkString(", ")})/
             |handshaked(${handshakedPeers.keys.map(formatPeer).toSeq.sorted.mkString(", ")})
-            | blacklisted(${blacklistedIds.map(_.value)mkString(", ")})
+            | blacklisted(${blacklistedIds.map(_.value).mkString(", ")})
             |""".stripMargin.replace("\n", " ")
       )
     }

From 23da5e762d9218e1e2d14dbe511d0372f1c409fa Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Wed, 10 Feb 2021 22:08:26 +0100
Subject: [PATCH 03/15] Fix FastSyncSpec

---
 .../io/iohk/ethereum/blockchain/sync/FastSyncSpec.scala  | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/test/scala/io/iohk/ethereum/blockchain/sync/FastSyncSpec.scala b/src/test/scala/io/iohk/ethereum/blockchain/sync/FastSyncSpec.scala
index ba88045b38..a1ca236ebb 100644
--- a/src/test/scala/io/iohk/ethereum/blockchain/sync/FastSyncSpec.scala
+++ b/src/test/scala/io/iohk/ethereum/blockchain/sync/FastSyncSpec.scala
@@ -14,6 +14,7 @@ import monix.reactive.Observable
 import io.iohk.ethereum.BlockHelpers
 import io.iohk.ethereum.blockchain.sync.fast.FastSync
 import io.iohk.ethereum.domain.ChainWeight
+import monix.execution.Scheduler
 
 import scala.concurrent.duration.DurationInt
 
@@ -25,8 +26,11 @@ class FastSyncSpec
   implicit val timeout: Timeout = Timeout(30.seconds)
 
   class Fixture extends EphemBlockchainTestSetup with TestSyncConfig with TestSyncPeers {
-    override implicit lazy val system = self.system
-    override implicit val scheduler = self.scheduler
+    override implicit lazy val system: ActorSystem = self.system
+    override implicit val scheduler: Scheduler = self.scheduler
+
+    val blacklistMaxElems: Int = 100
+    val blacklist: CacheBasedBlacklist = CacheBasedBlacklist.empty(blacklistMaxElems)
 
     override lazy val syncConfig: SyncConfig =
       defaultSyncConfig.copy(pivotBlockOffset = 5, fastSyncBlockValidationX = 5, fastSyncThrottle = 1.millis)
@@ -70,6 +74,7 @@ class FastSyncSpec
         validators = validators,
         peerEventBus = peerEventBus.ref,
         etcPeerManager = etcPeerManager.ref,
+        blacklist = blacklist,
         syncConfig = syncConfig,
         scheduler = system.scheduler
       )

From 68b263a28c9b5e007f66427fffd6330a544015e8 Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Thu, 11 Feb 2021 07:59:01 +0100
Subject: [PATCH 04/15] Update nix-sbt sha

---
 nix/pkgs/mantis.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nix/pkgs/mantis.nix b/nix/pkgs/mantis.nix
index 78186c85e8..3e83cd3e94 100644
--- a/nix/pkgs/mantis.nix
+++ b/nix/pkgs/mantis.nix
@@ -50,7 +50,7 @@ in sbt.mkDerivation {
 
   # This sha represents the change dependencies of mantis.
   # Update this sha whenever you change the dependencies
-  depsSha256 = "0gppwz6dvligrrgjmramyrm9723pwhg89cqfpxj22z2d86brwas2";
+  depsSha256 = "03wyskmiy6fsrsmaa4niksiaw8svmf31mv7hh6xczpjbkrrkwfnm";
 
   # this is the command used to to create the fixed-output-derivation
   depsWarmupCommand = "sbt compile --debug -Dnix=true";

From 29311a4176b2673fe92215432934593f7e263324 Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Thu, 11 Feb 2021 22:16:00 +0100
Subject: [PATCH 05/15] Update nix-sbt sha

---
 nix/pkgs/mantis.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nix/pkgs/mantis.nix b/nix/pkgs/mantis.nix
index 3e83cd3e94..acfe657ed3 100644
--- a/nix/pkgs/mantis.nix
+++ b/nix/pkgs/mantis.nix
@@ -50,7 +50,7 @@ in sbt.mkDerivation {
 
   # This sha represents the change dependencies of mantis.
   # Update this sha whenever you change the dependencies
-  depsSha256 = "03wyskmiy6fsrsmaa4niksiaw8svmf31mv7hh6xczpjbkrrkwfnm";
+  depsSha256 = "07iixw8va4zwpiln2zy2gr245z1ir4jd6pqgmkzhwnhw3mf5j28k";
 
   # this is the command used to to create the fixed-output-derivation
   depsWarmupCommand = "sbt compile --debug -Dnix=true";

From 72f7da8870e504f5769a99a6c2af4eea157576a0 Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Thu, 11 Feb 2021 22:16:33 +0100
Subject: [PATCH 06/15] Polish and add tests

---
 build.sbt                                     | 25 +++---
 project/Dependencies.scala                    |  9 ++-
 .../ethereum/blockchain/sync/Blacklist.scala  | 16 ++--
 .../blockchain/sync/SyncController.scala      |  2 +-
 .../blockchain/sync/fast/FastSync.scala       | 18 +++--
 .../sync/CacheBasedBlacklistSpec.scala        | 81 +++++++++++++++++++
 6 files changed, 125 insertions(+), 26 deletions(-)
 create mode 100644 src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala

diff --git a/build.sbt b/build.sbt
index 475eedebf9..6632d5e363 100644
--- a/build.sbt
+++ b/build.sbt
@@ -111,25 +111,26 @@ lazy val node = {
     Seq(
       Dependencies.akka,
       Dependencies.akkaHttp,
-      Dependencies.json4s,
-      Dependencies.circe,
+      Dependencies.apacheCommons,
       Dependencies.boopickle,
-      Dependencies.rocksDb,
-      Dependencies.enumeratum,
-      Dependencies.testing,
       Dependencies.cats,
-      Dependencies.monix,
-      Dependencies.network,
+      Dependencies.circe,
+      Dependencies.cli,
       Dependencies.crypto,
-      Dependencies.scopt,
+      Dependencies.dependencies,
+      Dependencies.enumeratum,
+      Dependencies.guava,
+      Dependencies.json4s,
+      Dependencies.kamon,
       Dependencies.logging,
-      Dependencies.apacheCommons,
       Dependencies.micrometer,
-      Dependencies.kamon,
+      Dependencies.monix,
+      Dependencies.network,
       Dependencies.prometheus,
-      Dependencies.cli,
+      Dependencies.rocksDb,
       Dependencies.scaffeine,
-      Dependencies.dependencies
+      Dependencies.scopt,
+      Dependencies.testing
     ).flatten ++ malletDeps
   }
 
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 020e8561b8..82aa858d85 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -112,12 +112,19 @@ object Dependencies {
     jline,
     "org.scala-lang.modules" %% "scala-parser-combinators" % "1.1.2",
     "org.scala-sbt.ipcsocket" % "ipcsocket" % "1.1.0",
-    "com.google.guava" % "guava" % "29.0-jre",
     "org.xerial.snappy" % "snappy-java" % "1.1.7.7",
     "org.web3j" % "core" % "5.0.0" % Test,
     "io.vavr" % "vavr" % "1.0.0-alpha-3"
   )
 
+  val guava: Seq[ModuleID] = {
+    val version = "30.1-jre"
+    Seq(
+      "com.google.guava" % "guava" % version,
+      "com.google.guava" % "guava-testlib" % version % "test"
+    )
+  }
+
   val prometheus: Seq[ModuleID] = {
     val provider = "io.prometheus"
     val version = "0.9.0"
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
index defa67bd90..c2248a3db0 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
@@ -1,11 +1,12 @@
 package io.iohk.ethereum.blockchain.sync
 
+import com.github.benmanes.caffeine.cache.Caffeine
 import com.github.blemale.scaffeine.{Cache, Scaffeine}
 import io.iohk.ethereum.blockchain.sync.BlacklistSupport.BlackListId
 import io.iohk.ethereum.utils.Logger
 
 import scala.concurrent.duration.FiniteDuration
-
+import scala.concurrent.duration._
 import scala.jdk.CollectionConverters._
 import scala.jdk.OptionConverters._
 import scala.jdk.DurationConverters._
@@ -21,12 +22,13 @@ final case class CacheBasedBlacklist(cache: Cache[BlackListId, String])
     extends Blacklist with Logger {
 
   override def isBlacklisted(id: BlackListId): Boolean = cache.getIfPresent(id).isDefined
+
   override def add(id: BlackListId, duration: FiniteDuration, reason: String): Unit =
     cache.policy().expireVariably().toScala.fold {
-      log.warn(s"Unexpected error while adding peer [$id] to blacklist using custom expiration time. Falling back to default expiration.")
+      log.warn(s"Unexpected error while adding peer [${id.value}] to blacklist using custom expiration time. Falling back to default expiration.")
       cache.put(id, reason)
-    } { ve =>
-      ve.put(id, reason, duration.toJava)
+    } { varExpirationPolicy =>
+      varExpirationPolicy.put(id, reason, duration.toJava)
     }
   override def remove(id: BlackListId): Unit = cache.invalidate(id)
 
@@ -35,11 +37,13 @@ final case class CacheBasedBlacklist(cache: Cache[BlackListId, String])
 
 object CacheBasedBlacklist {
 
-  // TODO check eviction strategy - we want to remove the oldest element if maxSize is reached
   def empty(maxSize: Int): CacheBasedBlacklist = {
     val cache =
       Scaffeine()
-        .maximumSize(maxSize)
+        .expireAfter[BlackListId, String](create = (_, _) => 60.minutes,
+          update = (_, _, _) => 60.minutes,
+          read = (_, _, _) => 60.minutes) // required to enable VarExpiration policy (i.e. set custom expiration time per element)
+        .maximumSize(maxSize) // uses Window TinyLfu eviction policy, see https://github.com/ben-manes/caffeine/wiki/Efficiency
         .build[BlackListId, String]()
     CacheBasedBlacklist(cache)
   }
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/SyncController.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/SyncController.scala
index 5a24db3d91..2d93223b38 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/SyncController.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/SyncController.scala
@@ -26,7 +26,7 @@ class SyncController(
 ) extends Actor
     with ActorLogging {
 
-  private val blacklistSize: Int = 100 // TODO move to config
+  private val blacklistSize: Int = 1000 // TODO ETCM-642 move to config
   private val blacklist: Blacklist = CacheBasedBlacklist.empty(blacklistSize)
 
   def scheduler: Scheduler = externalSchedulerOpt getOrElse context.system.scheduler
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
index b4a788abef..43937588ea 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
@@ -570,15 +570,21 @@ class FastSync(
       val formatPeer: Peer => String = peer =>
         s"${peer.remoteAddress.getAddress.getHostAddress}:${peer.remoteAddress.getPort}"
       val blacklistedIds = blacklist.keys
-      log.info(s"""|Block: ${appStateStorage.getBestBlockNumber()}/${syncState.pivotBlock.number}.
+      log.info(
+        s"""|Block: {}/${syncState.pivotBlock.number}.
             |Peers waiting_for_response/connected: ${assignedHandlers.size}/${handshakedPeers.size} (${blacklistedIds.size} blacklisted).
             |State: ${syncState.downloadedNodesCount}/${syncState.totalNodesCount} nodes.
-            |""".stripMargin.replace("\n", " "))
+            |""".stripMargin.replace("\n", " "),
+        appStateStorage.getBestBlockNumber()
+      )
       log.debug(
-        s"""|Connection status: connected(${assignedHandlers.values.map(formatPeer).toSeq.sorted.mkString(", ")})/
-            |handshaked(${handshakedPeers.keys.map(formatPeer).toSeq.sorted.mkString(", ")})
-            | blacklisted(${blacklistedIds.map(_.value).mkString(", ")})
-            |""".stripMargin.replace("\n", " ")
+        s"""|Connection status: connected({})/
+            |handshaked({})
+            | blacklisted({})
+            |""".stripMargin.replace("\n", " "),
+        assignedHandlers.values.map(formatPeer).toSeq.sorted.mkString(", "),
+        handshakedPeers.keys.map(formatPeer).toSeq.sorted.mkString(", "),
+        blacklistedIds.map(_.value).mkString(", ")
       )
     }
 
diff --git a/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala b/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
new file mode 100644
index 0000000000..05de674796
--- /dev/null
+++ b/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
@@ -0,0 +1,81 @@
+package io.iohk.ethereum.blockchain.sync
+
+import akka.actor.ActorSystem
+import akka.testkit.TestKit
+import io.iohk.ethereum.WithActorSystemShutDown
+import io.iohk.ethereum.network.PeerId
+import org.scalatest.matchers.must.Matchers
+import org.scalatest.wordspec.AnyWordSpecLike
+
+import scala.concurrent.duration._
+import com.google.common.testing.FakeTicker
+import com.github.blemale.scaffeine.Scaffeine
+import io.iohk.ethereum.blockchain.sync.BlacklistSupport.BlackListId
+import java.util.concurrent.TimeUnit
+
+class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
+
+  private val peer1 = PeerId("1")
+  private val peer2 = PeerId("2")
+  private val peer3 = PeerId("3")
+  private val peer4 = PeerId("4")
+  private val peer5 = PeerId("5")
+
+  private def withBlacklist(maxElements: Int)(test: CacheBasedBlacklist => Unit): Unit = {
+    val blacklist = CacheBasedBlacklist.empty(maxElements)
+    test(blacklist)
+  }
+
+  "CacheBasedBlacklist" should {
+    "add elements and respect max number of elements" in withBlacklist(3) { blacklist =>
+      blacklist.add(peer1, 1.minute, "just because")
+      blacklist.add(peer2, 1.minute, "just because")
+      blacklist.add(peer3, 1.minute, "just because")
+      blacklist.add(peer4, 1.minute, "just because")
+      blacklist.add(peer5, 1.minute, "just because")
+      blacklist.cache.cleanUp()
+      assert(blacklist.keys.size <= 3)
+    }
+    "should expire elements" in {
+      val maxSize = 10
+      val ticker = new FakeTicker()
+      val cache = Scaffeine()
+        .expireAfter[BlackListId, String](
+          create = (_, _) => 60.minutes,
+          update = (_, _, _) => 60.minutes,
+          read = (_, _, _) => 60.minutes
+        )
+        .maximumSize(
+          maxSize
+        )
+        .ticker(ticker.read _)
+        .build[BlackListId, String]()
+      val blacklist = CacheBasedBlacklist(cache)
+      blacklist.add(peer1, 1.minute, "just because")
+      blacklist.add(peer2, 10.minutes, "just because")
+      blacklist.add(peer3, 3.minute, "just because")
+      blacklist.add(peer4, 2.minute, "just because")
+      blacklist.add(peer5, 7.minutes, "just because")
+      ticker.advance(5, TimeUnit.MINUTES)
+      val expected = Set(peer2, peer5)
+      blacklist.cache.cleanUp()
+      blacklist.keys must contain theSameElementsAs expected
+    }
+    "check if given key is part of the list" in withBlacklist(3) { blacklist =>
+      blacklist.add(peer1, 1.minute, "just because")
+      blacklist.add(peer2, 1.minute, "just because")
+      blacklist.add(peer3, 1.minute, "just because")
+      assert(blacklist.isBlacklisted(peer2) === true)
+      assert(blacklist.isBlacklisted(PeerId("7")) === false)
+    }
+    "remove id from blacklist" in withBlacklist(3) { blacklist =>
+      blacklist.add(peer1, 1.minute, "just because")
+      blacklist.add(peer2, 1.minute, "just because")
+      blacklist.add(peer3, 1.minute, "just because")
+      assert(blacklist.isBlacklisted(peer2) === true)
+      blacklist.remove(peer2)
+      assert(blacklist.isBlacklisted(peer2) === false)
+    }
+  }
+
+}

From e53e760f7b8cf49004ca2288020b44cb8fbd3276 Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Thu, 11 Feb 2021 22:36:21 +0100
Subject: [PATCH 07/15] Rename BlackListId to BlacklistId

---
 .../ethereum/blockchain/sync/Blacklist.scala  | 34 ++++++++++++-------
 .../blockchain/sync/BlacklistSupport.scala    | 18 +++++-----
 .../scala/io/iohk/ethereum/network/Peer.scala | 10 +++---
 .../ethereum/network/PeerManagerActor.scala   |  4 +--
 .../sync/CacheBasedBlacklistSpec.scala        |  7 ++--
 5 files changed, 42 insertions(+), 31 deletions(-)

diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
index c2248a3db0..0707611abf 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
@@ -2,7 +2,6 @@ package io.iohk.ethereum.blockchain.sync
 
 import com.github.benmanes.caffeine.cache.Caffeine
 import com.github.blemale.scaffeine.{Cache, Scaffeine}
-import io.iohk.ethereum.blockchain.sync.BlacklistSupport.BlackListId
 import io.iohk.ethereum.utils.Logger
 
 import scala.concurrent.duration.FiniteDuration
@@ -11,28 +10,39 @@ import scala.jdk.CollectionConverters._
 import scala.jdk.OptionConverters._
 import scala.jdk.DurationConverters._
 
+import Blacklist.BlacklistId
+
 trait Blacklist {
-  def isBlacklisted(id: BlackListId): Boolean
-  def add(id: BlackListId, duration: FiniteDuration, reason: String): Unit
-  def remove(id: BlackListId): Unit
-  def keys: Set[BlackListId]
+
+  def isBlacklisted(id: BlacklistId): Boolean
+  def add(id: BlacklistId, duration: FiniteDuration, reason: String): Unit
+  def remove(id: BlacklistId): Unit
+  def keys: Set[BlacklistId]
+}
+
+object Blacklist {
+
+  trait BlacklistId {
+    def value: String
+  }
+
 }
 
-final case class CacheBasedBlacklist(cache: Cache[BlackListId, String])
+final case class CacheBasedBlacklist(cache: Cache[BlacklistId, String])
     extends Blacklist with Logger {
 
-  override def isBlacklisted(id: BlackListId): Boolean = cache.getIfPresent(id).isDefined
+  override def isBlacklisted(id: BlacklistId): Boolean = cache.getIfPresent(id).isDefined
 
-  override def add(id: BlackListId, duration: FiniteDuration, reason: String): Unit =
+  override def add(id: BlacklistId, duration: FiniteDuration, reason: String): Unit =
     cache.policy().expireVariably().toScala.fold {
       log.warn(s"Unexpected error while adding peer [${id.value}] to blacklist using custom expiration time. Falling back to default expiration.")
       cache.put(id, reason)
     } { varExpirationPolicy =>
       varExpirationPolicy.put(id, reason, duration.toJava)
     }
-  override def remove(id: BlackListId): Unit = cache.invalidate(id)
+  override def remove(id: BlacklistId): Unit = cache.invalidate(id)
 
-  override def keys: Set[BlackListId] = cache.underlying.asMap().keySet().asScala.toSet
+  override def keys: Set[BlacklistId] = cache.underlying.asMap().keySet().asScala.toSet
 }
 
 object CacheBasedBlacklist {
@@ -40,11 +50,11 @@ object CacheBasedBlacklist {
   def empty(maxSize: Int): CacheBasedBlacklist = {
     val cache =
       Scaffeine()
-        .expireAfter[BlackListId, String](create = (_, _) => 60.minutes,
+        .expireAfter[BlacklistId, String](create = (_, _) => 60.minutes,
           update = (_, _, _) => 60.minutes,
           read = (_, _, _) => 60.minutes) // required to enable VarExpiration policy (i.e. set custom expiration time per element)
         .maximumSize(maxSize) // uses Window TinyLfu eviction policy, see https://github.com/ben-manes/caffeine/wiki/Efficiency
-        .build[BlackListId, String]()
+        .build[BlacklistId, String]()
     CacheBasedBlacklist(cache)
   }
 
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/BlacklistSupport.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/BlacklistSupport.scala
index 6ab85e42db..12adcba0ff 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/BlacklistSupport.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/BlacklistSupport.scala
@@ -1,10 +1,13 @@
 package io.iohk.ethereum.blockchain.sync
 
-import scala.concurrent.duration.{Duration, FiniteDuration}
 import akka.actor.{Actor, ActorLogging, Cancellable, Scheduler}
+import io.iohk.ethereum.blockchain.sync.Blacklist.BlacklistId
+
 import scala.collection.mutable
 import scala.concurrent.ExecutionContext.Implicits.global
+import scala.concurrent.duration.{Duration, FiniteDuration}
 
+// will be removed once regular sync is switched to new blacklist implementation
 trait BlacklistSupport {
   selfActor: Actor with ActorLogging =>
 
@@ -14,9 +17,9 @@ trait BlacklistSupport {
 
   protected val maxBlacklistedNodes = 1000
 
-  val blacklistedPeers = mutable.LinkedHashMap.empty[BlackListId, Cancellable]
+  val blacklistedPeers = mutable.LinkedHashMap.empty[BlacklistId, Cancellable]
 
-  def blacklist(blacklistId: BlackListId, duration: FiniteDuration, reason: String): Unit = {
+  def blacklist(blacklistId: BlacklistId, duration: FiniteDuration, reason: String): Unit = {
     if (duration > Duration.Zero) {
       if (blacklistedPeers.size >= maxBlacklistedNodes) {
         removeOldestPeer()
@@ -30,13 +33,13 @@ trait BlacklistSupport {
     }
   }
 
-  def undoBlacklist(blacklistId: BlackListId): Unit = {
+  def undoBlacklist(blacklistId: BlacklistId): Unit = {
     val peer = blacklistedPeers.get(blacklistId)
     peer.foreach(_.cancel())
     blacklistedPeers.remove(blacklistId)
   }
 
-  def isBlacklisted(blacklistId: BlackListId): Boolean =
+  def isBlacklisted(blacklistId: BlacklistId): Boolean =
     blacklistedPeers.exists(_._1 == blacklistId)
 
   def handleBlacklistMessages: Receive = { case UnblacklistPeer(ref) =>
@@ -52,9 +55,6 @@ trait BlacklistSupport {
 
 object BlacklistSupport {
 
-  abstract class BlackListId {
-    def value: String
-  }
+  private case class UnblacklistPeer(blacklistId: BlacklistId)
 
-  private case class UnblacklistPeer(blacklistId: BlackListId)
 }
diff --git a/src/main/scala/io/iohk/ethereum/network/Peer.scala b/src/main/scala/io/iohk/ethereum/network/Peer.scala
index 3a61bfe5ee..1760dff90b 100644
--- a/src/main/scala/io/iohk/ethereum/network/Peer.scala
+++ b/src/main/scala/io/iohk/ethereum/network/Peer.scala
@@ -1,18 +1,18 @@
 package io.iohk.ethereum.network
 
-import java.net.InetSocketAddress
-
 import akka.actor.ActorRef
 import akka.util.ByteString
-import io.iohk.ethereum.blockchain.sync.BlacklistSupport.BlackListId
+import io.iohk.ethereum.blockchain.sync.Blacklist.BlacklistId
+
+import java.net.InetSocketAddress
 
-case class PeerId(value: String) extends BlackListId
+final case class PeerId(value: String) extends BlacklistId
 
 object PeerId {
   def fromRef(ref: ActorRef): PeerId = PeerId(ref.path.name)
 }
 
-case class Peer(
+final case class Peer(
     remoteAddress: InetSocketAddress,
     ref: ActorRef,
     incomingConnection: Boolean,
diff --git a/src/main/scala/io/iohk/ethereum/network/PeerManagerActor.scala b/src/main/scala/io/iohk/ethereum/network/PeerManagerActor.scala
index be3b51f15e..800b4a23fc 100644
--- a/src/main/scala/io/iohk/ethereum/network/PeerManagerActor.scala
+++ b/src/main/scala/io/iohk/ethereum/network/PeerManagerActor.scala
@@ -3,8 +3,8 @@ package io.iohk.ethereum.network
 import akka.actor.SupervisorStrategy.Stop
 import akka.actor._
 import akka.util.{ByteString, Timeout}
+import io.iohk.ethereum.blockchain.sync.Blacklist.BlacklistId
 import io.iohk.ethereum.blockchain.sync.BlacklistSupport
-import io.iohk.ethereum.blockchain.sync.BlacklistSupport.BlackListId
 import io.iohk.ethereum.jsonrpc.AkkaTaskOps.TaskActorOps
 import io.iohk.ethereum.network.PeerActor.PeerClosedConnection
 import io.iohk.ethereum.network.PeerActor.Status.Handshaked
@@ -521,7 +521,7 @@ object PeerManagerActor {
 
   case class OutgoingConnectionAlreadyHandled(uri: URI) extends ConnectionError
 
-  case class PeerAddress(value: String) extends BlackListId
+  case class PeerAddress(value: String) extends BlacklistId
 
   case object SchedulePruneIncomingPeers
   case class PruneIncomingPeers(stats: PeerStatisticsActor.StatsForAll)
diff --git a/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala b/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
index 05de674796..47c3f2e7a5 100644
--- a/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
+++ b/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
@@ -10,7 +10,8 @@ import org.scalatest.wordspec.AnyWordSpecLike
 import scala.concurrent.duration._
 import com.google.common.testing.FakeTicker
 import com.github.blemale.scaffeine.Scaffeine
-import io.iohk.ethereum.blockchain.sync.BlacklistSupport.BlackListId
+import io.iohk.ethereum.blockchain.sync.Blacklist.BlacklistId
+
 import java.util.concurrent.TimeUnit
 
 class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
@@ -40,7 +41,7 @@ class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
       val maxSize = 10
       val ticker = new FakeTicker()
       val cache = Scaffeine()
-        .expireAfter[BlackListId, String](
+        .expireAfter[BlacklistId, String](
           create = (_, _) => 60.minutes,
           update = (_, _, _) => 60.minutes,
           read = (_, _, _) => 60.minutes
@@ -49,7 +50,7 @@ class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
           maxSize
         )
         .ticker(ticker.read _)
-        .build[BlackListId, String]()
+        .build[BlacklistId, String]()
       val blacklist = CacheBasedBlacklist(cache)
       blacklist.add(peer1, 1.minute, "just because")
       blacklist.add(peer2, 10.minutes, "just because")

From 962fae2d394f41668158f3267741516a7b01f7ba Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Fri, 12 Feb 2021 09:43:20 +0100
Subject: [PATCH 08/15] Rework PeerListSupport a little bit

---
 .../ethereum/blockchain/sync/Blacklist.scala  |  3 -
 .../blockchain/sync/PeerListSupport.scala     |  1 +
 .../blockchain/sync/PeerListSupportNg.scala   | 58 +++++++++++--------
 .../blockchain/sync/fast/FastSync.scala       | 36 ++++++------
 4 files changed, 53 insertions(+), 45 deletions(-)

diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
index 0707611abf..18d9430351 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
@@ -13,7 +13,6 @@ import scala.jdk.DurationConverters._
 import Blacklist.BlacklistId
 
 trait Blacklist {
-
   def isBlacklisted(id: BlacklistId): Boolean
   def add(id: BlacklistId, duration: FiniteDuration, reason: String): Unit
   def remove(id: BlacklistId): Unit
@@ -21,11 +20,9 @@ trait Blacklist {
 }
 
 object Blacklist {
-
   trait BlacklistId {
     def value: String
   }
-
 }
 
 final case class CacheBasedBlacklist(cache: Cache[BlacklistId, String])
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupport.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupport.scala
index c5074f9fa8..25991899f5 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupport.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupport.scala
@@ -11,6 +11,7 @@ import io.iohk.ethereum.utils.Config.SyncConfig
 import scala.concurrent.duration._
 import scala.concurrent.ExecutionContext.Implicits.global
 
+// will be removed once regular sync is switched to new blacklist/peerlist implementation
 trait PeerListSupport {
   self: Actor with ActorLogging with BlacklistSupport =>
   import PeerListSupport._
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala
index 1666da3432..29ef214826 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala
@@ -8,56 +8,64 @@ import io.iohk.ethereum.network.PeerEventBusActor.{PeerSelector, Subscribe, Unsu
 import io.iohk.ethereum.network.{EtcPeerManagerActor, Peer, PeerId}
 import io.iohk.ethereum.utils.Config.SyncConfig
 
+import scala.concurrent.ExecutionContext
 import scala.concurrent.duration._
-import scala.concurrent.ExecutionContext.Implicits.global // FIXME copied from current impl but not sure global EC is a good choice
 
-trait PeerListSupportNg {
-  self: Actor with ActorLogging =>
+trait PeerListSupportNg { self: Actor with ActorLogging =>
   import PeerListSupportNg._
 
+  private implicit val ec: ExecutionContext = context.dispatcher
+
   def etcPeerManager: ActorRef
   def peerEventBus: ActorRef
   def blacklist: Blacklist
   def syncConfig: SyncConfig
   def scheduler: Scheduler
 
-  var handshakedPeers: PeersMap = Map.empty
+  protected var handshakedPeers: Map[PeerId, PeerWithInfo] = Map.empty
 
   scheduler.scheduleWithFixedDelay(
     0.seconds,
     syncConfig.peersScanInterval,
     etcPeerManager,
     EtcPeerManagerActor.GetHandshakedPeers
-  )(global, context.self)
+  )
 
-  def removePeer(peerId: PeerId): Unit = {
-    peerEventBus ! Unsubscribe(PeerDisconnectedClassifier(PeerSelector.WithId(peerId)))
-    handshakedPeers.find(_._1.id == peerId).foreach { case (peer, _) => blacklist.remove(peer.id) }
-    handshakedPeers = handshakedPeers.filterNot(_._1.id == peerId)
+  def handlePeerListMessages: Receive = {
+    case EtcPeerManagerActor.HandshakedPeers(peers) => updatePeers(peers)
+    case PeerDisconnected(peerId) => removePeer(peerId)
   }
 
-  def peersToDownloadFrom: PeersMap =
-    handshakedPeers.filterNot { case (p, _) => blacklist.isBlacklisted(p.id) }
+  def peersToDownloadFrom: Map[PeerId, PeerWithInfo] =
+    handshakedPeers.filterNot { case (peerId, _) =>
+      blacklist.isBlacklisted(peerId)
+    }
 
-  def handlePeerListMessages: Receive = {
-    case EtcPeerManagerActor.HandshakedPeers(peers) =>
-      peers.keys.filterNot(handshakedPeers.contains).foreach { peer =>
-        peerEventBus ! Subscribe(PeerDisconnectedClassifier(PeerSelector.WithId(peer.id)))
-      }
-      handshakedPeers = peers
-
-    case PeerDisconnected(peerId) if handshakedPeers.exists(_._1.id == peerId) =>
-      removePeer(peerId)
+  def peerById(peerId: PeerId): Option[Peer] = handshakedPeers.get(peerId).map(_.peer)
+
+  def blacklistIfHandshaked(peerId: PeerId, duration: FiniteDuration, reason: String): Unit =
+    handshakedPeers.get(peerId).foreach(_ => blacklist.add(peerId, duration, reason))
+
+  private def updatePeers(peers: Map[Peer, PeerInfo]): Unit = {
+    val updated = peers.map { case (peer, peerInfo) =>
+      (peer.id, PeerWithInfo(peer, peerInfo))
+    }
+    updated.filterNot(p => handshakedPeers.keySet.contains(p._1)).foreach { case (peerId, _) =>
+      peerEventBus ! Subscribe(PeerDisconnectedClassifier(PeerSelector.WithId(peerId)))
+    }
+    handshakedPeers = updated
   }
 
-  def peerById(peerId: PeerId): Option[Peer] = handshakedPeers collectFirst {
-    case (peer, _) if peer.id == peerId => peer
+  private def removePeer(peerId: PeerId): Unit = {
+    if (handshakedPeers.keySet.contains(peerId)) {
+      peerEventBus ! Unsubscribe(PeerDisconnectedClassifier(PeerSelector.WithId(peerId)))
+      blacklist.remove(peerId)
+      handshakedPeers = handshakedPeers - peerId
+    }
   }
 
-  def blacklistIfHandshaked(peer: Peer, duration: FiniteDuration, reason: String): Unit =
-    handshakedPeers.get(peer).foreach(_ => blacklist.add(peer.id, duration, reason))
 }
 
 object PeerListSupportNg {
-  type PeersMap = Map[Peer, PeerInfo]
+  final case class PeerWithInfo(peer: Peer, peerInfo: PeerInfo)
 }
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
index 43937588ea..bc5017ac4f 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
@@ -4,6 +4,7 @@ import java.time.Instant
 import akka.actor._
 import akka.util.ByteString
 import cats.data.NonEmptyList
+import io.iohk.ethereum.blockchain.sync.PeerListSupportNg.PeerWithInfo
 import io.iohk.ethereum.blockchain.sync.PeerRequestHandler.ResponseReceived
 import io.iohk.ethereum.blockchain.sync.SyncProtocol.Status.Progress
 import io.iohk.ethereum.blockchain.sync._
@@ -20,7 +21,7 @@ import io.iohk.ethereum.db.storage.{AppStateStorage, FastSyncStateStorage}
 import io.iohk.ethereum.domain._
 import io.iohk.ethereum.mpt.MerklePatriciaTrie
 import io.iohk.ethereum.network.EtcPeerManagerActor.PeerInfo
-import io.iohk.ethereum.network.Peer
+import io.iohk.ethereum.network.{Peer, PeerId}
 import io.iohk.ethereum.network.p2p.messages.Codes
 import io.iohk.ethereum.network.p2p.messages.PV62._
 import io.iohk.ethereum.network.p2p.messages.PV63._
@@ -541,7 +542,7 @@ class FastSync(
       requestedReceipts = requestedReceipts - handler
 
       requestedHeaders -= peer
-      if (handshakedPeers.contains(peer)) {
+      if (handshakedPeers.contains(peer.id)) {
         blacklist.add(peer.id, blacklistDuration, reason)
       }
     }
@@ -567,7 +568,8 @@ class FastSync(
     }
 
     private def printStatus(): Unit = {
-      val formatPeer: Peer => String = peer =>
+      def formatPeerEntry(entry: PeerWithInfo): String = formatPeer(entry.peer)
+      def formatPeer(peer: Peer): String =
         s"${peer.remoteAddress.getAddress.getHostAddress}:${peer.remoteAddress.getPort}"
       val blacklistedIds = blacklist.keys
       log.info(
@@ -583,7 +585,7 @@ class FastSync(
             | blacklisted({})
             |""".stripMargin.replace("\n", " "),
         assignedHandlers.values.map(formatPeer).toSeq.sorted.mkString(", "),
-        handshakedPeers.keys.map(formatPeer).toSeq.sorted.mkString(", "),
+        handshakedPeers.values.toList.map(e => formatPeerEntry(e)).sorted.mkString(", "),
         blacklistedIds.map(_.value).mkString(", ")
       )
     }
@@ -609,12 +611,12 @@ class FastSync(
     }
 
     private def getPeersWithFreshEnoughPivot(
-        peers: NonEmptyList[(Peer, PeerInfo)],
+        peers: NonEmptyList[PeerWithInfo],
         state: SyncState,
         syncConfig: SyncConfig
     ): List[(Peer, BigInt)] = {
       peers.collect {
-        case (peer, info) if hasBestBlockFreshEnoughToUpdatePivotBlock(info, state, syncConfig) =>
+        case PeerWithInfo(peer, info) if hasBestBlockFreshEnoughToUpdatePivotBlock(info, state, syncConfig) =>
           (peer, info.maxBlockNumber)
       }
     }
@@ -626,17 +628,17 @@ class FastSync(
       !(syncState.updatingPivotBlock || stateSyncRestartRequested)
 
     def pivotBlockIsStale(): Boolean = {
-      val currentPeers = peersToDownloadFrom.toList
-      if (currentPeers.isEmpty) {
+      val peersWithInfo = peersToDownloadFrom.values.toList
+      if (peersWithInfo.isEmpty) {
         false
       } else {
-        val peerWithBestBlockInNetwork = currentPeers.maxBy(peerWithNum => peerWithNum._2.maxBlockNumber)
+        val peerWithBestBlockInNetwork = peersWithInfo.maxBy(_.peerInfo.maxBlockNumber)
 
         val bestPossibleTargetDifferenceInNetwork =
-          (peerWithBestBlockInNetwork._2.maxBlockNumber - syncConfig.pivotBlockOffset) - syncState.pivotBlock.number
+          (peerWithBestBlockInNetwork.peerInfo.maxBlockNumber - syncConfig.pivotBlockOffset) - syncState.pivotBlock.number
 
         val peersWithTooFreshPossiblePivotBlock =
-          getPeersWithFreshEnoughPivot(NonEmptyList.fromListUnsafe(currentPeers), syncState, syncConfig)
+          getPeersWithFreshEnoughPivot(NonEmptyList.fromListUnsafe(peersWithInfo), syncState, syncConfig)
 
         if (peersWithTooFreshPossiblePivotBlock.isEmpty) {
           log.info(
@@ -652,7 +654,7 @@ class FastSync(
             "There are {} peers with possible new pivot block, " +
               "best known pivot in current peer list has number {}",
             peersWithTooFreshPossiblePivotBlock.size,
-            peerWithBestBlockInNetwork._2.maxBlockNumber
+            peerWithBestBlockInNetwork.peerInfo.maxBlockNumber
           )
 
           pivotBlockIsStale
@@ -715,7 +717,7 @@ class FastSync(
           .filter(p => peerRequestsTime.get(p.peer).forall(d => d.plusMillis(fastSyncThrottle.toMillis).isBefore(now)))
         peers
           .take(maxConcurrentRequests - assignedHandlers.size)
-          .sortBy(_.info.maxBlockNumber)(Ordering[BigInt].reverse)
+          .sortBy(_.peerInfo.maxBlockNumber)(Ordering[BigInt].reverse)
           .foreach(assignBlockchainWork)
       }
     }
@@ -803,8 +805,10 @@ class FastSync(
       peerRequestsTime += (peer -> Instant.now())
     }
 
-    def unassignedPeers: List[PeerWithInfo] =
-      (peersToDownloadFrom -- assignedHandlers.values).map(PeerWithInfo.tupled).toList
+    def unassignedPeers: List[PeerWithInfo] = {
+      val assignedPeers = assignedHandlers.values.map(_.id).toList
+      peersToDownloadFrom.removedAll(assignedPeers).values.toList
+    }
 
     def blockchainDataToDownload: Boolean =
       syncState.blockChainWorkQueued || syncState.bestBlockHeaderNumber < syncState.safeDownloadTarget
@@ -838,8 +842,6 @@ class FastSync(
 
 object FastSync {
 
-  case class PeerWithInfo(peer: Peer, info: PeerInfo)
-
   // scalastyle:off parameter.number
   def props(
       fastSyncStateStorage: FastSyncStateStorage,

From 93d85f12bc5f0b29aa9f8e7a5621a04bc51da95d Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Fri, 12 Feb 2021 16:44:10 +0100
Subject: [PATCH 09/15] Small cleanup

---
 .../ethereum/blockchain/sync/Blacklist.scala  | 31 ++++++++++++-------
 .../blockchain/sync/fast/FastSync.scala       | 10 +++---
 2 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
index 18d9430351..d171b3d257 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
@@ -25,18 +25,23 @@ object Blacklist {
   }
 }
 
-final case class CacheBasedBlacklist(cache: Cache[BlacklistId, String])
-    extends Blacklist with Logger {
+final case class CacheBasedBlacklist(cache: Cache[BlacklistId, String]) extends Blacklist with Logger {
 
   override def isBlacklisted(id: BlacklistId): Boolean = cache.getIfPresent(id).isDefined
 
   override def add(id: BlacklistId, duration: FiniteDuration, reason: String): Unit =
-    cache.policy().expireVariably().toScala.fold {
-      log.warn(s"Unexpected error while adding peer [${id.value}] to blacklist using custom expiration time. Falling back to default expiration.")
-      cache.put(id, reason)
-    } { varExpirationPolicy =>
-      varExpirationPolicy.put(id, reason, duration.toJava)
-    }
+    cache
+      .policy()
+      .expireVariably()
+      .toScala
+      .fold {
+        log.warn(
+          s"Unexpected error while adding peer [${id.value}] to blacklist using custom expiration time. Falling back to default expiration."
+        )
+        cache.put(id, reason)
+      } { varExpirationPolicy =>
+        varExpirationPolicy.put(id, reason, duration.toJava)
+      }
   override def remove(id: BlacklistId): Unit = cache.invalidate(id)
 
   override def keys: Set[BlacklistId] = cache.underlying.asMap().keySet().asScala.toSet
@@ -47,10 +52,14 @@ object CacheBasedBlacklist {
   def empty(maxSize: Int): CacheBasedBlacklist = {
     val cache =
       Scaffeine()
-        .expireAfter[BlacklistId, String](create = (_, _) => 60.minutes,
+        .expireAfter[BlacklistId, String](
+          create = (_, _) => 60.minutes,
           update = (_, _, _) => 60.minutes,
-          read = (_, _, _) => 60.minutes) // required to enable VarExpiration policy (i.e. set custom expiration time per element)
-        .maximumSize(maxSize) // uses Window TinyLfu eviction policy, see https://github.com/ben-manes/caffeine/wiki/Efficiency
+          read = (_, _, _) => 60.minutes
+        ) // required to enable VarExpiration policy (i.e. set custom expiration time per element)
+        .maximumSize(
+          maxSize
+        ) // uses Window TinyLfu eviction policy, see https://github.com/ben-manes/caffeine/wiki/Efficiency
         .build[BlacklistId, String]()
     CacheBasedBlacklist(cache)
   }
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
index bc5017ac4f..77fc399aff 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
@@ -59,9 +59,7 @@ class FastSync(
 
   override def receive: Receive = idle
 
-  def handleCommonMessages: Receive = handlePeerListMessages
-
-  def idle: Receive = handleCommonMessages orElse {
+  def idle: Receive = handlePeerListMessages orElse {
     case SyncProtocol.Start => start()
     case SyncProtocol.GetStatus => sender() ! SyncProtocol.Status.NotSyncing
   }
@@ -90,7 +88,7 @@ class FastSync(
     context become waitingForPivotBlock
   }
 
-  def waitingForPivotBlock: Receive = handleCommonMessages orElse {
+  def waitingForPivotBlock: Receive = handlePeerListMessages orElse {
     case SyncProtocol.GetStatus => sender() ! SyncProtocol.Status.NotSyncing
     case PivotBlockSelector.Result(pivotBlockHeader) =>
       if (pivotBlockHeader.number < 1) {
@@ -161,7 +159,7 @@ class FastSync(
         syncState = syncState.copy(downloadedNodesCount = saved, totalNodesCount = saved + missing)
     }
 
-    def receive: Receive = handleCommonMessages orElse handleStatus orElse {
+    def receive: Receive = handlePeerListMessages orElse handleStatus orElse {
       case UpdatePivotBlock(reason) => updatePivotBlock(reason)
       case WaitingForNewTargetBlock =>
         log.info("State sync stopped until receiving new pivot block")
@@ -248,7 +246,7 @@ class FastSync(
     }
 
     def waitingForPivotBlockUpdate(updateReason: PivotBlockUpdateReason): Receive =
-      handleCommonMessages orElse handleStatus orElse {
+      handlePeerListMessages orElse handleStatus orElse {
         case PivotBlockSelector.Result(pivotBlockHeader)
             if newPivotIsGoodEnough(pivotBlockHeader, syncState, updateReason) =>
           log.info("New pivot block with number {} received", pivotBlockHeader.number)

From c5dd35c298462b1a964e5ea54465955c05d5759b Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Sun, 14 Feb 2021 22:02:45 +0100
Subject: [PATCH 10/15] [ETCM-531] Turn blacklist reasons into proper types,
 small improvements based on PR comments

---
 .../sync/util/FastSyncItSpecUtils.scala       |   5 +
 .../ethereum/blockchain/sync/Blacklist.scala  | 130 +++++++++++++++---
 .../blockchain/sync/PeerListSupportNg.scala   |   9 +-
 .../blockchain/sync/fast/FastSync.scala       |  35 ++---
 .../sync/CacheBasedBlacklistSpec.scala        |  42 +++---
 5 files changed, 159 insertions(+), 62 deletions(-)

diff --git a/src/it/scala/io/iohk/ethereum/sync/util/FastSyncItSpecUtils.scala b/src/it/scala/io/iohk/ethereum/sync/util/FastSyncItSpecUtils.scala
index f8059f7115..e563286b24 100644
--- a/src/it/scala/io/iohk/ethereum/sync/util/FastSyncItSpecUtils.scala
+++ b/src/it/scala/io/iohk/ethereum/sync/util/FastSyncItSpecUtils.scala
@@ -17,6 +17,7 @@ import monix.eval.Task
 import scala.annotation.tailrec
 import scala.concurrent.duration._
 import scala.util.Try
+import io.iohk.ethereum.blockchain.sync.CacheBasedBlacklist
 object FastSyncItSpecUtils {
 
   class FakePeer(peerName: String, fakePeerCustomConfig: FakePeerCustomConfig)
@@ -24,6 +25,9 @@ object FastSyncItSpecUtils {
 
     lazy val validators = new MockValidatorsAlwaysSucceed
 
+    val maxSize = 1000
+    val blacklist = CacheBasedBlacklist.empty(maxSize)
+
     lazy val fastSync = system.actorOf(
       FastSync.props(
         storagesInstance.storages.fastSyncStateStorage,
@@ -32,6 +36,7 @@ object FastSyncItSpecUtils {
         validators,
         peerEventBus,
         etcPeerManager,
+        blacklist,
         testSyncConfig,
         system.scheduler
       )
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
index d171b3d257..fe2c2fbc55 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
@@ -10,38 +10,129 @@ import scala.jdk.CollectionConverters._
 import scala.jdk.OptionConverters._
 import scala.jdk.DurationConverters._
 
-import Blacklist.BlacklistId
+import Blacklist._
+import io.iohk.ethereum.network.PeerId
+import io.iohk.ethereum.blockchain.sync.Blacklist.BlacklistReason.BlacklistReasonType.WrongBlockHeadersType
+import io.iohk.ethereum.consensus.validators.std.StdBlockValidator.BlockError
+import io.iohk.ethereum.blockchain.sync.Blacklist.BlacklistReason.BlacklistReasonType
 
 trait Blacklist {
   def isBlacklisted(id: BlacklistId): Boolean
-  def add(id: BlacklistId, duration: FiniteDuration, reason: String): Unit
+  def add(id: BlacklistId, duration: FiniteDuration, reason: BlacklistReason): Unit
   def remove(id: BlacklistId): Unit
   def keys: Set[BlacklistId]
 }
 
 object Blacklist {
+  import BlacklistReason._
+  import BlacklistReasonType._
+
   trait BlacklistId {
     def value: String
   }
+
+  sealed trait BlacklistReason {
+    def reasonType: BlacklistReasonType
+    def description: String
+  }
+  object BlacklistReason {
+    trait BlacklistReasonType {
+      def code: Int
+      def name: String
+    }
+    object BlacklistReasonType {
+      case object WrongBlockHeadersType extends BlacklistReasonType {
+        val code: Int = 1
+        val name: String = "WrongBlockHeadersType"
+      }
+      case object BlockHeaderValidationFailedType extends BlacklistReasonType {
+        val code: Int = 2
+        val name: String = "BlockHeaderValidationFailed"
+      }
+      case object ErrorInBlockHeadersType extends BlacklistReasonType {
+        val code: Int = 3
+        val name: String = "ErrorInBlockHeaders"
+      }
+      case object EmptyBlockBodiesType extends BlacklistReasonType {
+        val code: Int = 4
+        val name: String = "EmptyBlockBodies"
+      }
+      case object BlockBodiesNotMatchingHeadersType extends BlacklistReasonType {
+        val code: Int = 5
+        val name: String = "BlockBodiesNotMatchingHeaders"
+      }
+      case object EmptyReceiptsType extends BlacklistReasonType {
+        val code: Int = 6
+        val name: String = "EmptyReceipts"
+      }
+      case object InvalidReceiptsType extends BlacklistReasonType {
+        val code: Int = 7
+        val name: String = "InvalidReceipts"
+      }
+      case object RequestFailedType extends BlacklistReasonType {
+        val code: Int = 8
+        val name: String = "RequestFailed"
+      }
+      case object PeerActorTerminatedType extends BlacklistReasonType {
+        val code: Int = 9
+        val name: String = "PeerActorTerminated"
+      }
+    }
+
+    case object WrongBlockHeaders extends BlacklistReason {
+      val reasonType: BlacklistReasonType = WrongBlockHeadersType
+      val description: String = "Wrong blockheaders response (empty or not chain forming)"
+    }
+    case object BlockHeaderValidationFailed extends BlacklistReason {
+      val reasonType: BlacklistReasonType = BlockHeaderValidationFailedType
+      val description: String = "Block header validation failed"
+    }
+    case object ErrorInBlockHeaders extends BlacklistReason {
+      val reasonType: BlacklistReasonType = ErrorInBlockHeadersType
+      val description: String = "Error in block headers response"
+    }
+    final case class EmptyBlockBodies(knownHashes: Seq[String]) extends BlacklistReason {
+      val reasonType: BlacklistReasonType = EmptyBlockBodiesType
+      val description: String = s"Got empty block bodies response for known hashes: $knownHashes"
+    }
+    case object BlockBodiesNotMatchingHeaders extends BlacklistReason {
+      val reasonType: BlacklistReasonType = BlockBodiesNotMatchingHeadersType
+      val description = "Block bodies not matching block headers"
+    }
+    final case class EmptyReceipts(knownHashes: Seq[String]) extends BlacklistReason {
+      val reasonType: BlacklistReasonType = EmptyReceiptsType
+      val description: String = s"Got empty receipts for known hashes: $knownHashes"
+    }
+    final case class InvalidReceipts(knownHashes: Seq[String], error: BlockError) extends BlacklistReason {
+      val reasonType: BlacklistReasonType = InvalidReceiptsType
+      val description: String = s"Got invalid receipts for known hashes: $knownHashes due to: $error"
+    }
+    final case class RequestFailed(error: String) extends BlacklistReason {
+      val reasonType: BlacklistReasonType = RequestFailedType
+      val description: String = s"Request failed with error: $error"
+    }
+    case object PeerActorTerminated extends BlacklistReason {
+      val reasonType: BlacklistReasonType = PeerActorTerminatedType
+      val description: String = "Peer actor terminated"
+    }
+  }
 }
 
-final case class CacheBasedBlacklist(cache: Cache[BlacklistId, String]) extends Blacklist with Logger {
+final case class CacheBasedBlacklist(cache: Cache[BlacklistId, BlacklistReasonType]) extends Blacklist with Logger {
+
+  import CacheBasedBlacklist._
 
   override def isBlacklisted(id: BlacklistId): Boolean = cache.getIfPresent(id).isDefined
 
-  override def add(id: BlacklistId, duration: FiniteDuration, reason: String): Unit =
-    cache
-      .policy()
-      .expireVariably()
-      .toScala
-      .fold {
-        log.warn(
-          s"Unexpected error while adding peer [${id.value}] to blacklist using custom expiration time. Falling back to default expiration."
-        )
-        cache.put(id, reason)
-      } { varExpirationPolicy =>
-        varExpirationPolicy.put(id, reason, duration.toJava)
-      }
+  override def add(id: BlacklistId, duration: FiniteDuration, reason: BlacklistReason): Unit = {
+    log.debug("Blacklisting peer [{}] for {}. Reason: {}", id, duration, reason)
+    cache.policy().expireVariably().toScala match {
+      case Some(varExpiration) => varExpiration.put(id, reason.reasonType, duration.toJava)
+      case None =>
+        log.warn(customExpirationError(id))
+        cache.put(id, reason.reasonType)
+    }
+  }
   override def remove(id: BlacklistId): Unit = cache.invalidate(id)
 
   override def keys: Set[BlacklistId] = cache.underlying.asMap().keySet().asScala.toSet
@@ -49,10 +140,13 @@ final case class CacheBasedBlacklist(cache: Cache[BlacklistId, String]) extends
 
 object CacheBasedBlacklist {
 
+  def customExpirationError(id: BlacklistId): String =
+    s"Unexpected error while adding peer [${id.value}] to blacklist using custom expiration time. Falling back to default expiration."
+
   def empty(maxSize: Int): CacheBasedBlacklist = {
     val cache =
       Scaffeine()
-        .expireAfter[BlacklistId, String](
+        .expireAfter[BlacklistId, BlacklistReasonType](
           create = (_, _) => 60.minutes,
           update = (_, _, _) => 60.minutes,
           read = (_, _, _) => 60.minutes
@@ -60,7 +154,7 @@ object CacheBasedBlacklist {
         .maximumSize(
           maxSize
         ) // uses Window TinyLfu eviction policy, see https://github.com/ben-manes/caffeine/wiki/Efficiency
-        .build[BlacklistId, String]()
+        .build[BlacklistId, BlacklistReasonType]()
     CacheBasedBlacklist(cache)
   }
 
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala
index 29ef214826..e5a032f2e5 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala
@@ -13,6 +13,7 @@ import scala.concurrent.duration._
 
 trait PeerListSupportNg { self: Actor with ActorLogging =>
   import PeerListSupportNg._
+  import Blacklist._
 
   private implicit val ec: ExecutionContext = context.dispatcher
 
@@ -33,7 +34,7 @@ trait PeerListSupportNg { self: Actor with ActorLogging =>
 
   def handlePeerListMessages: Receive = {
     case EtcPeerManagerActor.HandshakedPeers(peers) => updatePeers(peers)
-    case PeerDisconnected(peerId) => removePeer(peerId)
+    case PeerDisconnected(peerId) => removePeerById(peerId)
   }
 
   def peersToDownloadFrom: Map[PeerId, PeerWithInfo] =
@@ -41,9 +42,9 @@ trait PeerListSupportNg { self: Actor with ActorLogging =>
       blacklist.isBlacklisted(peerId)
     }
 
-  def peerById(peerId: PeerId): Option[Peer] = handshakedPeers.get(peerId).map(_.peer)
+  def getPeerById(peerId: PeerId): Option[Peer] = handshakedPeers.get(peerId).map(_.peer)
 
-  def blacklistIfHandshaked(peerId: PeerId, duration: FiniteDuration, reason: String): Unit =
+  def blacklistIfHandshaked(peerId: PeerId, duration: FiniteDuration, reason: BlacklistReason): Unit =
     handshakedPeers.get(peerId).foreach(_ => blacklist.add(peerId, duration, reason))
 
   private def updatePeers(peers: Map[Peer, PeerInfo]): Unit = {
@@ -56,7 +57,7 @@ trait PeerListSupportNg { self: Actor with ActorLogging =>
     handshakedPeers = updated
   }
 
-  private def removePeer(peerId: PeerId): Unit = {
+  private def removePeerById(peerId: PeerId): Unit = {
     if (handshakedPeers.keySet.contains(peerId)) {
       peerEventBus ! Unsubscribe(PeerDisconnectedClassifier(PeerSelector.WithId(peerId)))
       blacklist.remove(peerId)
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
index 77fc399aff..f9301c6be4 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala
@@ -8,6 +8,8 @@ import io.iohk.ethereum.blockchain.sync.PeerListSupportNg.PeerWithInfo
 import io.iohk.ethereum.blockchain.sync.PeerRequestHandler.ResponseReceived
 import io.iohk.ethereum.blockchain.sync.SyncProtocol.Status.Progress
 import io.iohk.ethereum.blockchain.sync._
+import io.iohk.ethereum.blockchain.sync.Blacklist._
+import io.iohk.ethereum.blockchain.sync.Blacklist.BlacklistReason._
 import io.iohk.ethereum.blockchain.sync.fast.ReceiptsValidator.ReceiptsValidationResult
 import io.iohk.ethereum.blockchain.sync.fast.SyncBlocksValidator.BlockBodyValidationResult
 import io.iohk.ethereum.blockchain.sync.fast.SyncStateSchedulerActor.{
@@ -183,7 +185,7 @@ class FastSync(
           )
             handleBlockHeaders(peer, blockHeaders)
           else
-            blacklist.add(peer.id, blacklistDuration, "wrong blockheaders response (empty or not chain forming)")
+            blacklist.add(peer.id, blacklistDuration, WrongBlockHeaders)
         }
 
       case ResponseReceived(peer, BlockBodies(blockBodies), timeTaken) =>
@@ -205,10 +207,10 @@ class FastSync(
         handleReceipts(peer, requestedHashes, receipts)
 
       case PeerRequestHandler.RequestFailed(peer, reason) =>
-        handleRequestFailure(peer, sender(), reason)
+        handleRequestFailure(peer, sender(), RequestFailed(reason))
 
       case Terminated(ref) if assignedHandlers.contains(ref) =>
-        handleRequestFailure(assignedHandlers(ref), ref, "Unexpected error")
+        handleRequestFailure(assignedHandlers(ref), ref, PeerActorTerminated)
     }
 
     def askForPivotBlockUpdate(updateReason: PivotBlockUpdateReason): Unit = {
@@ -423,7 +425,7 @@ class FastSync(
     }
 
     private def handleRewind(header: BlockHeader, peer: Peer, N: Int, duration: FiniteDuration): Unit = {
-      blacklist.add(peer.id, duration, "block header validation failed")
+      blacklist.add(peer.id, duration, BlockHeaderValidationFailed)
       if (header.number <= syncState.safeDownloadTarget) {
         discardLastBlocks(header.number, N)
         syncState = syncState.updateDiscardedBlocks(header, N)
@@ -461,27 +463,22 @@ class FastSync(
             )
         }
       } else {
-        blacklist.add(peer.id, blacklistDuration, "error in block headers response")
+        blacklist.add(peer.id, blacklistDuration, ErrorInBlockHeaders)
         processSyncing()
       }
     }
 
     private def handleBlockBodies(peer: Peer, requestedHashes: Seq[ByteString], blockBodies: Seq[BlockBody]): Unit = {
       if (blockBodies.isEmpty) {
-        val reason =
-          s"got empty block bodies response for known hashes: ${requestedHashes.map(ByteStringUtils.hash2string)}"
-        blacklist.add(peer.id, blacklistDuration, reason)
+        val knownHashes = requestedHashes.map(ByteStringUtils.hash2string)
+        blacklist.add(peer.id, blacklistDuration, EmptyBlockBodies(knownHashes))
         syncState = syncState.enqueueBlockBodies(requestedHashes)
       } else {
         validateBlocks(requestedHashes, blockBodies) match {
           case BlockBodyValidationResult.Valid =>
             insertBlocks(requestedHashes, blockBodies)
           case BlockBodyValidationResult.Invalid =>
-            blacklist.add(
-              peer.id,
-              blacklistDuration,
-              s"responded with block bodies not matching block headers, blacklisting for $blacklistDuration"
-            )
+            blacklist.add(peer.id, blacklistDuration, BlockBodiesNotMatchingHeaders)
             syncState = syncState.enqueueBlockBodies(requestedHashes)
           case BlockBodyValidationResult.DbError =>
             redownloadBlockchain()
@@ -493,8 +490,8 @@ class FastSync(
 
     private def handleReceipts(peer: Peer, requestedHashes: Seq[ByteString], receipts: Seq[Seq[Receipt]]): Unit = {
       if (receipts.isEmpty) {
-        val reason = s"got empty receipts for known hashes: ${requestedHashes.map(ByteStringUtils.hash2string)}"
-        blacklist.add(peer.id, blacklistDuration, reason)
+        val knownHashes = requestedHashes.map(ByteStringUtils.hash2string)
+        blacklist.add(peer.id, blacklistDuration, EmptyReceipts(knownHashes))
         syncState = syncState.enqueueReceipts(requestedHashes)
       } else {
         validateReceipts(requestedHashes, receipts) match {
@@ -515,10 +512,8 @@ class FastSync(
             }
 
           case ReceiptsValidationResult.Invalid(error) =>
-            val reason =
-              s"got invalid receipts for known hashes: ${requestedHashes.map(h => Hex.toHexString(h.toArray[Byte]))}" +
-                s" due to: $error"
-            blacklist.add(peer.id, blacklistDuration, reason)
+            val knownHashes = requestedHashes.map(h => Hex.toHexString(h.toArray[Byte]))
+            blacklist.add(peer.id, blacklistDuration, InvalidReceipts(knownHashes, error))
             syncState = syncState.enqueueReceipts(requestedHashes)
 
           case ReceiptsValidationResult.DbError =>
@@ -529,7 +524,7 @@ class FastSync(
       processSyncing()
     }
 
-    private def handleRequestFailure(peer: Peer, handler: ActorRef, reason: String): Unit = {
+    private def handleRequestFailure(peer: Peer, handler: ActorRef, reason: BlacklistReason): Unit = {
       removeRequestHandler(handler)
 
       syncState = syncState
diff --git a/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala b/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
index 47c3f2e7a5..774061a552 100644
--- a/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
+++ b/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
@@ -10,11 +10,10 @@ import org.scalatest.wordspec.AnyWordSpecLike
 import scala.concurrent.duration._
 import com.google.common.testing.FakeTicker
 import com.github.blemale.scaffeine.Scaffeine
-import io.iohk.ethereum.blockchain.sync.Blacklist.BlacklistId
-
 import java.util.concurrent.TimeUnit
 
 class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
+  import Blacklist._
 
   private val peer1 = PeerId("1")
   private val peer2 = PeerId("2")
@@ -22,6 +21,9 @@ class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
   private val peer4 = PeerId("4")
   private val peer5 = PeerId("5")
 
+  private val reason = BlacklistReason.ErrorInBlockHeaders
+  private val anotherReason = BlacklistReason.BlockBodiesNotMatchingHeaders
+
   private def withBlacklist(maxElements: Int)(test: CacheBasedBlacklist => Unit): Unit = {
     val blacklist = CacheBasedBlacklist.empty(maxElements)
     test(blacklist)
@@ -29,11 +31,11 @@ class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
 
   "CacheBasedBlacklist" should {
     "add elements and respect max number of elements" in withBlacklist(3) { blacklist =>
-      blacklist.add(peer1, 1.minute, "just because")
-      blacklist.add(peer2, 1.minute, "just because")
-      blacklist.add(peer3, 1.minute, "just because")
-      blacklist.add(peer4, 1.minute, "just because")
-      blacklist.add(peer5, 1.minute, "just because")
+      blacklist.add(peer1, 1.minute, reason)
+      blacklist.add(peer2, 1.minute, reason)
+      blacklist.add(peer3, 1.minute, anotherReason)
+      blacklist.add(peer4, 1.minute, anotherReason)
+      blacklist.add(peer5, 1.minute, reason)
       blacklist.cache.cleanUp()
       assert(blacklist.keys.size <= 3)
     }
@@ -41,7 +43,7 @@ class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
       val maxSize = 10
       val ticker = new FakeTicker()
       val cache = Scaffeine()
-        .expireAfter[BlacklistId, String](
+        .expireAfter[BlacklistId, BlacklistReason.BlacklistReasonType](
           create = (_, _) => 60.minutes,
           update = (_, _, _) => 60.minutes,
           read = (_, _, _) => 60.minutes
@@ -50,29 +52,29 @@ class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
           maxSize
         )
         .ticker(ticker.read _)
-        .build[BlacklistId, String]()
+        .build[BlacklistId, BlacklistReason.BlacklistReasonType]()
       val blacklist = CacheBasedBlacklist(cache)
-      blacklist.add(peer1, 1.minute, "just because")
-      blacklist.add(peer2, 10.minutes, "just because")
-      blacklist.add(peer3, 3.minute, "just because")
-      blacklist.add(peer4, 2.minute, "just because")
-      blacklist.add(peer5, 7.minutes, "just because")
+      blacklist.add(peer1, 1.minute, reason)
+      blacklist.add(peer2, 10.minutes, reason)
+      blacklist.add(peer3, 3.minute, anotherReason)
+      blacklist.add(peer4, 2.minute, reason)
+      blacklist.add(peer5, 7.minutes, reason)
       ticker.advance(5, TimeUnit.MINUTES)
       val expected = Set(peer2, peer5)
       blacklist.cache.cleanUp()
       blacklist.keys must contain theSameElementsAs expected
     }
     "check if given key is part of the list" in withBlacklist(3) { blacklist =>
-      blacklist.add(peer1, 1.minute, "just because")
-      blacklist.add(peer2, 1.minute, "just because")
-      blacklist.add(peer3, 1.minute, "just because")
+      blacklist.add(peer1, 1.minute, reason)
+      blacklist.add(peer2, 1.minute, anotherReason)
+      blacklist.add(peer3, 1.minute, reason)
       assert(blacklist.isBlacklisted(peer2) === true)
       assert(blacklist.isBlacklisted(PeerId("7")) === false)
     }
     "remove id from blacklist" in withBlacklist(3) { blacklist =>
-      blacklist.add(peer1, 1.minute, "just because")
-      blacklist.add(peer2, 1.minute, "just because")
-      blacklist.add(peer3, 1.minute, "just because")
+      blacklist.add(peer1, 1.minute, reason)
+      blacklist.add(peer2, 1.minute, anotherReason)
+      blacklist.add(peer3, 1.minute, reason)
       assert(blacklist.isBlacklisted(peer2) === true)
       blacklist.remove(peer2)
       assert(blacklist.isBlacklisted(peer2) === false)

From cefeea97fbfa0ad6c443e50b7aa765be2342997b Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Mon, 15 Feb 2021 07:46:24 +0100
Subject: [PATCH 11/15] Make BlacklistReasonType a sealed trait

---
 src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
index fe2c2fbc55..b49d4c589e 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
@@ -36,7 +36,7 @@ object Blacklist {
     def description: String
   }
   object BlacklistReason {
-    trait BlacklistReasonType {
+    sealed trait BlacklistReasonType {
       def code: Int
       def name: String
     }

From 32c2c053f69d72f2bae01bbc3225796cfb959796 Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Mon, 15 Feb 2021 12:25:01 +0100
Subject: [PATCH 12/15] Only log description for blacklist reason

---
 src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
index b49d4c589e..125186cdf1 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
@@ -125,7 +125,7 @@ final case class CacheBasedBlacklist(cache: Cache[BlacklistId, BlacklistReasonTy
   override def isBlacklisted(id: BlacklistId): Boolean = cache.getIfPresent(id).isDefined
 
   override def add(id: BlacklistId, duration: FiniteDuration, reason: BlacklistReason): Unit = {
-    log.debug("Blacklisting peer [{}] for {}. Reason: {}", id, duration, reason)
+    log.debug("Blacklisting peer [{}] for {}. Reason: {}", id, duration, reason.description)
     cache.policy().expireVariably().toScala match {
       case Some(varExpiration) => varExpiration.put(id, reason.reasonType, duration.toJava)
       case None =>

From c1a1e9924713f322a9af25c8fa7125eebde9b2a9 Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Tue, 16 Feb 2021 09:06:59 +0100
Subject: [PATCH 13/15] ETCM-531 renamed minute -> minutes

---
 .../ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala    | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala b/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
index 774061a552..d8443895fa 100644
--- a/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
+++ b/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
@@ -56,8 +56,8 @@ class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
       val blacklist = CacheBasedBlacklist(cache)
       blacklist.add(peer1, 1.minute, reason)
       blacklist.add(peer2, 10.minutes, reason)
-      blacklist.add(peer3, 3.minute, anotherReason)
-      blacklist.add(peer4, 2.minute, reason)
+      blacklist.add(peer3, 3.minutes, anotherReason)
+      blacklist.add(peer4, 2.minutes, reason)
       blacklist.add(peer5, 7.minutes, reason)
       ticker.advance(5, TimeUnit.MINUTES)
       val expected = Set(peer2, peer5)

From 248907c94e3faa9ae3c228ea04c16e50c249127f Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Tue, 16 Feb 2021 09:58:39 +0100
Subject: [PATCH 14/15] ETCM-531 Reformat triggered by running sbt pp

---
 .../scala/io/iohk/ethereum/network/PeerManagerSpec.scala   | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/test/scala/io/iohk/ethereum/network/PeerManagerSpec.scala b/src/test/scala/io/iohk/ethereum/network/PeerManagerSpec.scala
index e00dd4f057..2a90ef385c 100644
--- a/src/test/scala/io/iohk/ethereum/network/PeerManagerSpec.scala
+++ b/src/test/scala/io/iohk/ethereum/network/PeerManagerSpec.scala
@@ -310,8 +310,11 @@ class PeerManagerSpec
 
     time.advance(360000) // wait till the peer is out of the blacklist
 
-    val newRoundDiscoveredNodes = discoveredNodes + Node.fromUri(new java.net.URI(
-      "enode://a59e33ccd2b3e52d578f1fbd70c6f9babda2650f0760d6ff3b37742fdcdfdb3defba5d56d315b40c46b70198c7621e63ffa3f987389c7118634b0fefbbdfa7fd@51.158.191.43:38556?discport=38556"))
+    val newRoundDiscoveredNodes = discoveredNodes + Node.fromUri(
+      new java.net.URI(
+        "enode://a59e33ccd2b3e52d578f1fbd70c6f9babda2650f0760d6ff3b37742fdcdfdb3defba5d56d315b40c46b70198c7621e63ffa3f987389c7118634b0fefbbdfa7fd@51.158.191.43:38556?discport=38556"
+      )
+    )
 
     peerManager ! PeerDiscoveryManager.DiscoveredNodesInfo(newRoundDiscoveredNodes)
 

From 25d6eeec11a12775821bc16cdb7fd3eadfaa1242 Mon Sep 17 00:00:00 2001
From: Petra Bierleutgeb <petra.bierleutgeb@iohk.io>
Date: Tue, 16 Feb 2021 19:59:48 +0100
Subject: [PATCH 15/15] ETCM-531 Fix expiration after read

---
 .../scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala | 4 ++--
 .../iohk/ethereum/blockchain/sync/PeerListSupportNg.scala  | 2 +-
 .../ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala | 7 +++++--
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
index 125186cdf1..8aa0f568a5 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/Blacklist.scala
@@ -125,7 +125,7 @@ final case class CacheBasedBlacklist(cache: Cache[BlacklistId, BlacklistReasonTy
   override def isBlacklisted(id: BlacklistId): Boolean = cache.getIfPresent(id).isDefined
 
   override def add(id: BlacklistId, duration: FiniteDuration, reason: BlacklistReason): Unit = {
-    log.debug("Blacklisting peer [{}] for {}. Reason: {}", id, duration, reason.description)
+    log.info("Blacklisting peer [{}] for {}. Reason: {}", id, duration, reason.description)
     cache.policy().expireVariably().toScala match {
       case Some(varExpiration) => varExpiration.put(id, reason.reasonType, duration.toJava)
       case None =>
@@ -149,7 +149,7 @@ object CacheBasedBlacklist {
         .expireAfter[BlacklistId, BlacklistReasonType](
           create = (_, _) => 60.minutes,
           update = (_, _, _) => 60.minutes,
-          read = (_, _, _) => 60.minutes
+          read = (_, _, duration) => duration // read access should not change the expiration time
         ) // required to enable VarExpiration policy (i.e. set custom expiration time per element)
         .maximumSize(
           maxSize
diff --git a/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala b/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala
index e5a032f2e5..0bca267ce1 100644
--- a/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala
+++ b/src/main/scala/io/iohk/ethereum/blockchain/sync/PeerListSupportNg.scala
@@ -30,7 +30,7 @@ trait PeerListSupportNg { self: Actor with ActorLogging =>
     syncConfig.peersScanInterval,
     etcPeerManager,
     EtcPeerManagerActor.GetHandshakedPeers
-  )
+  )(ec, context.self)
 
   def handlePeerListMessages: Receive = {
     case EtcPeerManagerActor.HandshakedPeers(peers) => updatePeers(peers)
diff --git a/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala b/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
index d8443895fa..afb8ec5cee 100644
--- a/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
+++ b/src/test/scala/io/iohk/ethereum/blockchain/sync/CacheBasedBlacklistSpec.scala
@@ -37,7 +37,8 @@ class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
       blacklist.add(peer4, 1.minute, anotherReason)
       blacklist.add(peer5, 1.minute, reason)
       blacklist.cache.cleanUp()
-      assert(blacklist.keys.size <= 3)
+      val size = blacklist.keys.size
+      assert(size <= 3 && size > 0)
     }
     "should expire elements" in {
       val maxSize = 10
@@ -46,7 +47,7 @@ class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
         .expireAfter[BlacklistId, BlacklistReason.BlacklistReasonType](
           create = (_, _) => 60.minutes,
           update = (_, _, _) => 60.minutes,
-          read = (_, _, _) => 60.minutes
+          read = (_, _, duration) => duration
         )
         .maximumSize(
           maxSize
@@ -59,6 +60,8 @@ class CacheBasedBlacklistSpec extends AnyWordSpecLike with Matchers {
       blacklist.add(peer3, 3.minutes, anotherReason)
       blacklist.add(peer4, 2.minutes, reason)
       blacklist.add(peer5, 7.minutes, reason)
+      blacklist.isBlacklisted(peer2) // just to simulate a read
+      blacklist.keys // just to simulate a read
       ticker.advance(5, TimeUnit.MINUTES)
       val expected = Set(peer2, peer5)
       blacklist.cache.cleanUp()