Update fast-sync-min-peers default value for post merge (#4298)

Signed-off-by: Karim TAAM <karim.t2am@gmail.com>

CHANGELOG.md

@@ -6,6 +6,7 @@
 - Upgrade besu-native to 0.6.0 and use Blake2bf native implementation if available by default [#4264](https://github.com/hyperledger/besu/pull/4264)
 - Better management of jemalloc presence/absence in startup script [#4237](https://github.com/hyperledger/besu/pull/4237)
 - Filter out disconnected peers when fetching available peers [#4269](https://github.com/hyperledger/besu/pull/4269)
+- Updated the default value of fast-sync-min-peers post merge [#4298](https://github.com/hyperledger/besu/pull/4298)
 
 ### Bug Fixes
 - Accept wit/80 from Nethermind [#4279](https://github.com/hyperledger/besu/pull/4279)

besu/src/main/java/org/hyperledger/besu/cli/BesuCommand.java

@@ -20,6 +20,7 @@ import static java.util.Arrays.asList;
 import static java.util.Collections.singletonList;
 import static org.hyperledger.besu.cli.DefaultCommandValues.getDefaultBesuDataPath;
 import static org.hyperledger.besu.cli.config.NetworkName.MAINNET;
+import static org.hyperledger.besu.cli.config.NetworkName.isMergedNetwork;
 import static org.hyperledger.besu.cli.util.CommandLineUtils.DEPENDENCY_WARNING_MSG;
 import static org.hyperledger.besu.cli.util.CommandLineUtils.DEPRECATED_AND_USELESS_WARNING_MSG;
 import static org.hyperledger.besu.cli.util.CommandLineUtils.DEPRECATION_WARNING_MSG;
@@ -507,8 +508,12 @@ public class BesuCommand implements DefaultCommandValues, Runnable {
       names = {"--fast-sync-min-peers"},
       paramLabel = MANDATORY_INTEGER_FORMAT_HELP,
       description =
-          "Minimum number of peers required before starting fast sync. (default: ${DEFAULT-VALUE})")
-  private final Integer fastSyncMinPeerCount = FAST_SYNC_MIN_PEER_COUNT;
+          "Minimum number of peers required before starting fast sync. (default pre-merge: "
+              + FAST_SYNC_MIN_PEER_COUNT
+              + " and post-merge: "
+              + FAST_SYNC_MIN_PEER_COUNT_POST_MERGE
+              + ")")
+  private final Integer fastSyncMinPeerCount = null;
 
   @Option(
       names = {"--network"},
@@ -2783,10 +2788,19 @@ public class BesuCommand implements DefaultCommandValues, Runnable {
   }
 
   private SynchronizerConfiguration buildSyncConfig() {
+    Integer fastSyncMinPeers = fastSyncMinPeerCount;
+    if (fastSyncMinPeers == null) {
+      if (isMergedNetwork(network)) {
+        fastSyncMinPeers = FAST_SYNC_MIN_PEER_COUNT_POST_MERGE;
+      } else {
+        fastSyncMinPeers = FAST_SYNC_MIN_PEER_COUNT;
+      }
+    }
+
     return unstableSynchronizerOptions
         .toDomainObject()
         .syncMode(syncMode)
-        .fastSyncMinimumPeerCount(fastSyncMinPeerCount)
+        .fastSyncMinimumPeerCount(fastSyncMinPeers)
         .build();
   }
 

besu/src/main/java/org/hyperledger/besu/cli/DefaultCommandValues.java

@@ -57,6 +57,7 @@ public interface DefaultCommandValues {
   NatMethod DEFAULT_NAT_METHOD = NatMethod.AUTO;
   JwtAlgorithm DEFAULT_JWT_ALGORITHM = JwtAlgorithm.RS256;
   int FAST_SYNC_MIN_PEER_COUNT = 5;
+  int FAST_SYNC_MIN_PEER_COUNT_POST_MERGE = 1;
   int DEFAULT_MAX_PEERS = 25;
   int DEFAULT_P2P_PEER_LOWER_BOUND = 25;
   int DEFAULT_HTTP_MAX_CONNECTIONS = 80;

besu/src/main/java/org/hyperledger/besu/cli/config/NetworkName.java

@@ -86,4 +86,16 @@ public enum NetworkName {
   public Optional<String> getDeprecationDate() {
     return Optional.ofNullable(deprecationDate);
   }
+
+  public static boolean isMergedNetwork(final NetworkName networkName) {
+    switch (networkName) {
+      case GOERLI:
+      case ROPSTEN:
+      case SEPOLIA:
+      case KILN:
+        return true;
+      default:
+        return false;
+    }
+  }
 }

besu/src/test/java/org/hyperledger/besu/cli/BesuCommandTest.java

@@ -1706,6 +1706,42 @@ public class BesuCommandTest extends CommandTestAbstract {
     assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
   }
 
+  @Test
+  public void checkValidDefaultFastSyncMinPeersOption() {
+    parseCommand("--sync-mode", "FAST");
+    verify(mockControllerBuilder).synchronizerConfiguration(syncConfigurationCaptor.capture());
+
+    final SynchronizerConfiguration syncConfig = syncConfigurationCaptor.getValue();
+    assertThat(syncConfig.getSyncMode()).isEqualTo(SyncMode.FAST);
+    assertThat(syncConfig.getFastSyncMinimumPeerCount()).isEqualTo(5);
+    assertThat(commandOutput.toString(UTF_8)).isEmpty();
+    assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
+  }
+
+  @Test
+  public void checkValidDefaultFastSyncMinPeersPreMergeOption() {
+    parseCommand("--sync-mode", "FAST", "--network", "CLASSIC");
+    verify(mockControllerBuilder).synchronizerConfiguration(syncConfigurationCaptor.capture());
+
+    final SynchronizerConfiguration syncConfig = syncConfigurationCaptor.getValue();
+    assertThat(syncConfig.getSyncMode()).isEqualTo(SyncMode.FAST);
+    assertThat(syncConfig.getFastSyncMinimumPeerCount()).isEqualTo(5);
+    assertThat(commandOutput.toString(UTF_8)).isEmpty();
+    assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
+  }
+
+  @Test
+  public void checkValidDefaultFastSyncMinPeersPostMergeOption() {
+    parseCommand("--sync-mode", "FAST", "--network", "GOERLI");
+    verify(mockControllerBuilder).synchronizerConfiguration(syncConfigurationCaptor.capture());
+
+    final SynchronizerConfiguration syncConfig = syncConfigurationCaptor.getValue();
+    assertThat(syncConfig.getSyncMode()).isEqualTo(SyncMode.FAST);
+    assertThat(syncConfig.getFastSyncMinimumPeerCount()).isEqualTo(1);
+    assertThat(commandOutput.toString(UTF_8)).isEmpty();
+    assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
+  }
+
   @Test
   public void parsesValidFastSyncMinPeersOption() {
     parseCommand("--sync-mode", "FAST", "--fast-sync-min-peers", "11");
@@ -1718,6 +1754,30 @@ public class BesuCommandTest extends CommandTestAbstract {
     assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
   }
 
+  @Test
+  public void parsesValidFastSyncMinPeersOptionPreMerge() {
+    parseCommand("--sync-mode", "FAST", "--network", "CLASSIC", "--fast-sync-min-peers", "11");
+    verify(mockControllerBuilder).synchronizerConfiguration(syncConfigurationCaptor.capture());
+
+    final SynchronizerConfiguration syncConfig = syncConfigurationCaptor.getValue();
+    assertThat(syncConfig.getSyncMode()).isEqualTo(SyncMode.FAST);
+    assertThat(syncConfig.getFastSyncMinimumPeerCount()).isEqualTo(11);
+    assertThat(commandOutput.toString(UTF_8)).isEmpty();
+    assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
+  }
+
+  @Test
+  public void parsesValidFastSyncMinPeersOptionPostMerge() {
+    parseCommand("--sync-mode", "FAST", "--network", "GOERLI", "--fast-sync-min-peers", "11");
+    verify(mockControllerBuilder).synchronizerConfiguration(syncConfigurationCaptor.capture());
+
+    final SynchronizerConfiguration syncConfig = syncConfigurationCaptor.getValue();
+    assertThat(syncConfig.getSyncMode()).isEqualTo(SyncMode.FAST);
+    assertThat(syncConfig.getFastSyncMinimumPeerCount()).isEqualTo(11);
+    assertThat(commandOutput.toString(UTF_8)).isEmpty();
+    assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
+  }
+
   @Test
   public void parsesInvalidFastSyncMinPeersOptionWrongFormatShouldFail() {