feat: Move to fully connected network

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/builder/PlatformComponentBuilder.java

@@ -1025,7 +1025,6 @@ public Gossip buildGossip() {
         if (gossip == null) {
             gossip = new SyncGossip(
                     blocks.platformContext(),
-                    blocks.randomBuilder().buildNonCryptographicRandom(),
                     AdHocThreadManager.getStaticThreadManager(),
                     blocks.keysAndCerts(),
                     blocks.initialAddressBook(),

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/gossip/FallenBehindManagerImpl.java

@@ -18,7 +18,7 @@
 
 import com.swirlds.common.merkle.synchronization.config.ReconnectConfig;
 import com.swirlds.common.platform.NodeId;
-import com.swirlds.platform.network.RandomGraph;
+import com.swirlds.platform.network.topology.NetworkTopology;
 import com.swirlds.platform.system.address.AddressBook;
 import com.swirlds.platform.system.status.StatusActionSubmitter;
 import com.swirlds.platform.system.status.actions.FallenBehindAction;
@@ -38,11 +38,12 @@ public class FallenBehindManagerImpl implements FallenBehindManager {
     /**
      * a set of all neighbors of this node
      */
-    private final HashSet<NodeId> allNeighbors;
+    private final Set<NodeId> allNeighbors;
     /**
      * the number of neighbors we have
      */
     private final int numNeighbors;
+
     /**
      * set of neighbors who report that this node has fallen behind
      */
@@ -72,23 +73,19 @@ public class FallenBehindManagerImpl implements FallenBehindManager {
     public FallenBehindManagerImpl(
             @NonNull final AddressBook addressBook,
             @NonNull final NodeId selfId,
-            @NonNull final RandomGraph connectionGraph,
+            @NonNull final NetworkTopology topology,
             @NonNull final StatusActionSubmitter statusActionSubmitter,
             @NonNull final Runnable fallenBehindCallback,
             @NonNull final ReconnectConfig config) {
         Objects.requireNonNull(addressBook, "addressBook");
         Objects.requireNonNull(selfId, "selfId");
-        Objects.requireNonNull(connectionGraph, "connectionGraph");
+        Objects.requireNonNull(topology, "topology");
 
         notYetReportFallenBehind = ConcurrentHashMap.newKeySet();
         reportFallenBehind = new HashSet<>();
-        allNeighbors = new HashSet<>();
-        /* an array with all the neighbor ids */
-        final int[] neighbors = connectionGraph.getNeighbors(addressBook.getIndexOfNodeId(selfId));
-        numNeighbors = neighbors.length;
-        for (final int neighbor : neighbors) {
-            allNeighbors.add(addressBook.getNodeId(neighbor));
-        }
+        allNeighbors = topology.getNeighbors();
+        numNeighbors = allNeighbors.size();
+
         this.statusActionSubmitter = Objects.requireNonNull(statusActionSubmitter);
         this.fallenBehindCallback =
                 Objects.requireNonNull(fallenBehindCallback, "fallenBehindCallback must not be null");
@@ -137,7 +134,7 @@ public synchronized List<NodeId> getNeighborsForReconnect() {
     }
 
     @Override
-    public boolean shouldReconnectFrom(final NodeId peerId) {
+    public boolean shouldReconnectFrom(@NonNull final NodeId peerId) {
         if (!hasFallenBehind()) {
             return false;
         }

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/gossip/SyncGossip.java

@@ -93,7 +93,6 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
-import java.util.Random;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
@@ -156,7 +155,6 @@ public class SyncGossip implements ConnectionTracker, Gossip {
      * Builds the gossip engine, depending on which flavor is requested in the configuration.
      *
      * @param platformContext               the platform context
-     * @param random                        a source of randomness, does not need to be cryptographically secure
      * @param threadManager                 the thread manager
      * @param keysAndCerts                  private keys and public certificates
      * @param addressBook                   the current address book
@@ -173,7 +171,6 @@ public class SyncGossip implements ConnectionTracker, Gossip {
      */
     public SyncGossip(
             @NonNull final PlatformContext platformContext,
-            @NonNull final Random random,
             @NonNull final ThreadManager threadManager,
             @NonNull final KeysAndCerts keysAndCerts,
             @NonNull final AddressBook addressBook,
@@ -199,9 +196,9 @@ public SyncGossip(
         final ThreadConfig threadConfig = platformContext.getConfiguration().getConfigData(ThreadConfig.class);
 
         final BasicConfig basicConfig = platformContext.getConfiguration().getConfigData(BasicConfig.class);
-
-        topology = new StaticTopology(random, addressBook, selfId, basicConfig.numConnections());
         final List<PeerInfo> peers = Utilities.createPeerInfoList(addressBook, selfId);
+
+        topology = new StaticTopology(peers, selfId);
         final NetworkPeerIdentifier peerIdentifier = new NetworkPeerIdentifier(platformContext, peers);
         final SocketFactory socketFactory =
                 NetworkUtils.createSocketFactory(selfId, peers, keysAndCerts, platformContext.getConfiguration());
@@ -231,7 +228,7 @@ public SyncGossip(
         fallenBehindManager = new FallenBehindManagerImpl(
                 addressBook,
                 selfId,
-                topology.getConnectionGraph(),
+                topology,
                 statusActionSubmitter,
                 () -> getReconnectController().start(),
                 platformContext.getConfiguration().getConfigData(ReconnectConfig.class));

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/network/topology/NetworkTopology.java

@@ -17,9 +17,7 @@
 package com.swirlds.platform.network.topology;
 
 import com.swirlds.common.platform.NodeId;
-import com.swirlds.platform.network.RandomGraph;
-import java.util.List;
-import java.util.function.Predicate;
+import java.util.Set;
 
 /**
  * Holds information about the topology of the network
@@ -44,17 +42,7 @@ public interface NetworkTopology {
     boolean shouldConnectToMe(NodeId nodeId);
 
     /**
-     * @return a list of all peers this node should be connected to
+     * @return a Set of all peers this node should be connected to
      */
-    List<NodeId> getNeighbors();
-
-    /**
-     * @return a list of peers this node should be connected to with the applied filter
-     */
-    List<NodeId> getNeighbors(final Predicate<NodeId> filter);
-
-    /**
-     * @return the underlying graph on which this topology is based on
-     */
-    RandomGraph getConnectionGraph();
+    Set<NodeId> getNeighbors();
 }

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/network/topology/StaticTopology.java

@@ -17,108 +17,55 @@
 package com.swirlds.platform.network.topology;
 
 import com.swirlds.common.platform.NodeId;
-import com.swirlds.platform.network.RandomGraph;
-import com.swirlds.platform.system.address.AddressBook;
+import com.swirlds.platform.network.PeerInfo;
 import edu.umd.cs.findbugs.annotations.NonNull;
-import java.util.Arrays;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Objects;
-import java.util.Random;
-import java.util.function.Predicate;
+import java.util.Set;
 
 /**
- * A bidirectional topology that never changes.
+ * A fully connected topology that never changes.
  */
 public class StaticTopology implements NetworkTopology {
-    private static final long SEED = 0;
 
-    private final NodeId selfId;
-    /**
-     * Two nodes are neighbors if their indexes in the address book are neighbors in the connection graph.
-     */
-    private final AddressBook addressBook;
+    private final Set<NodeId> nodeIds = new HashSet<>();
 
-    private final RandomGraph connectionGraph;
+    private final NodeId selfId;
 
     /**
      * Constructor.
-     *
-     * @param random            a source of randomness, used to chose random neighbors, does not need to be
-     *                          cryptographically secure
-     * @param addressBook       the current address book
+     * @param peers             the set of peers in the network
      * @param selfId            the ID of this node
-     * @param numberOfNeighbors the number of neighbors each node should have
      */
-    public StaticTopology(
-            @NonNull final Random random,
-            @NonNull final AddressBook addressBook,
-            @NonNull final NodeId selfId,
-            final int numberOfNeighbors) {
-        this.addressBook = Objects.requireNonNull(addressBook, "addressBook must not be null");
-        this.selfId = Objects.requireNonNull(selfId, "selfId must not be null");
-        this.connectionGraph = new RandomGraph(random, addressBook.getSize(), numberOfNeighbors, SEED);
-
-        if (!addressBook.contains(selfId)) {
-            throw new IllegalArgumentException("Address book does not contain selfId");
-        }
-    }
-
-    /**
-     * {@inheritDoc}
-     */
-    @Override
-    public List<NodeId> getNeighbors() {
-        return getNeighbors((nodeId -> true));
+    public StaticTopology(@NonNull final List<PeerInfo> peers, @NonNull final NodeId selfId) {
+        Objects.requireNonNull(peers);
+        Objects.requireNonNull(selfId);
+        peers.forEach(peer -> nodeIds.add(peer.nodeId()));
+        this.selfId = selfId;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
-    public List<NodeId> getNeighbors(final Predicate<NodeId> filter) {
-        final int selfIndex = addressBook.getIndexOfNodeId(selfId);
-        return Arrays.stream(connectionGraph.getNeighbors(selfIndex))
-                .mapToObj(addressBook::getNodeId)
-                .filter(filter)
-                .toList();
+    public Set<NodeId> getNeighbors() {
+        return nodeIds;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean shouldConnectToMe(final NodeId nodeId) {
-        return isNeighbor(nodeId) && addressBook.getIndexOfNodeId(nodeId) < addressBook.getIndexOfNodeId(selfId);
-    }
-
-    /**
-     * Queries the topology on whether this node is my neighbor
-     *
-     * @param nodeId the ID of the node being queried
-     * @return true if this node is my neighbor, false if not
-     */
-    private boolean isNeighbor(final NodeId nodeId) {
-        if (!addressBook.contains(nodeId)) {
-            return false;
-        }
-        final int selfIndex = addressBook.getIndexOfNodeId(selfId);
-        final int nodeIndex = addressBook.getIndexOfNodeId(nodeId);
-        return connectionGraph.isAdjacent(selfIndex, nodeIndex);
+        return nodeIds.contains(nodeId) && nodeId.id() < selfId.id();
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean shouldConnectTo(final NodeId nodeId) {
-        return isNeighbor(nodeId) && addressBook.getIndexOfNodeId(nodeId) > addressBook.getIndexOfNodeId(selfId);
-    }
-
-    /**
-     * {@inheritDoc}
-     */
-    @Override
-    public RandomGraph getConnectionGraph() {
-        return connectionGraph;
+        return nodeIds.contains(nodeId) && nodeId.id() > selfId.id();
     }
 }

platform-sdk/swirlds-platform-core/src/test/java/com/swirlds/platform/DummyHashgraph.java

@@ -37,7 +37,7 @@ public class DummyHashgraph {
         isInCriticalQuorum = new HashMap<>();
         numUserTransEvents = 0;
         lastRoundReceivedAllTransCons = 0;
-        addressBook = RandomAddressBookBuilder.create(random).withSize(100).build();
+        addressBook = RandomAddressBookBuilder.create(random).withSize(41).build();
         this.selfId = addressBook.getNodeId(selfIndex);
     }
 

platform-sdk/swirlds-platform-core/src/test/java/com/swirlds/platform/SyncManagerTest.java

@@ -18,6 +18,7 @@
 
 import static com.swirlds.common.test.fixtures.RandomUtils.getRandomPrintSeed;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.Mockito.mock;
@@ -34,7 +35,9 @@
 import com.swirlds.platform.eventhandling.EventConfig_;
 import com.swirlds.platform.gossip.FallenBehindManagerImpl;
 import com.swirlds.platform.gossip.sync.SyncManagerImpl;
-import com.swirlds.platform.network.RandomGraph;
+import com.swirlds.platform.network.PeerInfo;
+import com.swirlds.platform.network.topology.NetworkTopology;
+import com.swirlds.platform.network.topology.StaticTopology;
 import com.swirlds.platform.pool.TransactionPoolNexus;
 import com.swirlds.platform.system.address.AddressBook;
 import com.swirlds.platform.system.status.StatusActionSubmitter;
@@ -57,7 +60,6 @@ private static class SyncManagerTestData {
         public AddressBook addressBook;
         public NodeId selfId;
         public TransactionPoolNexus transactionPoolNexus;
-        public RandomGraph connectionGraph;
         public SyncManagerImpl syncManager;
         public Configuration configuration;
 
@@ -71,23 +73,24 @@ public SyncManagerTestData() {
 
             this.addressBook = hashgraph.getAddressBook();
             this.selfId = addressBook.getNodeId(0);
-            final int size = addressBook.getSize();
 
-            connectionGraph = new RandomGraph(random, size, 40, 0);
             configuration = new TestConfigBuilder()
                     .withValue(ReconnectConfig_.FALLEN_BEHIND_THRESHOLD, "0.25")
                     .withValue(EventConfig_.EVENT_INTAKE_QUEUE_THROTTLE_SIZE, "100")
                     .getOrCreateConfig();
             final ReconnectConfig reconnectConfig = configuration.getConfigData(ReconnectConfig.class);
             final EventConfig eventConfig = configuration.getConfigData(EventConfig.class);
 
+            final List<PeerInfo> peers = Utilities.createPeerInfoList(addressBook, selfId);
+            final NetworkTopology topology = new StaticTopology(peers, selfId);
+
             syncManager = new SyncManagerImpl(
                     platformContext,
                     hashgraph::getEventIntakeQueueSize,
                     new FallenBehindManagerImpl(
                             addressBook,
                             selfId,
-                            connectionGraph,
+                            topology,
                             mock(StatusActionSubmitter.class),
                             () -> {},
                             reconnectConfig),
@@ -103,24 +106,24 @@ public SyncManagerTestData() {
     void basicTest() {
         final SyncManagerTestData test = new SyncManagerTestData();
 
-        final int[] neighbors = test.connectionGraph.getNeighbors(0);
+        final List<PeerInfo> peers = Utilities.createPeerInfoList(test.addressBook, test.selfId);
 
         // we should not think we have fallen behind initially
         assertFalse(test.syncManager.hasFallenBehind());
         // should be null as we have no indication of falling behind
         assertNull(test.syncManager.getNeededForFallenBehind());
 
         // neighbors 0 and 1 report fallen behind
-        test.syncManager.reportFallenBehind(test.addressBook.getNodeId(neighbors[0]));
-        test.syncManager.reportFallenBehind(test.addressBook.getNodeId(neighbors[1]));
+        test.syncManager.reportFallenBehind(peers.get(0).nodeId());
+        test.syncManager.reportFallenBehind(peers.get(1).nodeId());
 
         // we still dont have enough reports that we have fallen behind, we need more than [fallenBehindThreshold] of
         // the neighbors
         assertFalse(test.syncManager.hasFallenBehind());
 
         // add more reports
         for (int i = 2; i < 10; i++) {
-            test.syncManager.reportFallenBehind(test.addressBook.getNodeId(neighbors[i]));
+            test.syncManager.reportFallenBehind(peers.get(i).nodeId());
         }
 
         // we are still missing 1 report
@@ -131,12 +134,12 @@ void basicTest() {
         for (final NodeId nodeId : list) {
             // none of the nodes we need to call should be those who already reported we have fallen behind
             for (int i = 0; i < 10; i++) {
-                assertTrue(test.addressBook.getIndexOfNodeId(nodeId) != neighbors[i]);
+                assertNotEquals(nodeId.id(), peers.get(i).nodeId().id());
             }
         }
 
         // add the report that will go over the [fallenBehindThreshold]
-        test.syncManager.reportFallenBehind(test.addressBook.getNodeId(neighbors[10]));
+        test.syncManager.reportFallenBehind(peers.get(10).nodeId());
 
         // we should now say we have fallen behind
         assertTrue(test.syncManager.hasFallenBehind());