From a856fa36d3959b5b15d3430074eca39d7fa3812f Mon Sep 17 00:00:00 2001
From: Manfred Karrer <mk@nucleo.io>
Date: Wed, 27 Jan 2016 18:26:51 +0100
Subject: [PATCH] Refactor handshake out for peers request

---
 .../OfferAvailabilityProtocol.java            |  16 +-
 .../settings/network/NetworkSettingsView.fxml |   5 +-
 .../java/io/bitsquare/p2p/P2PService.java     |   9 +-
 .../p2p/peers/PeerExchangeHandshake.java      | 208 +++++++++++++++
 .../p2p/peers/PeerExchangeManager.java        | 246 +++++++-----------
 .../io/bitsquare/p2p/peers/PeerManager.java   |   8 +-
 .../p2p/peers/RequestDataHandshake.java       | 102 +++++---
 .../p2p/peers/RequestDataManager.java         |  35 ++-
 .../peers/messages/peers/GetPeersRequest.java |   5 +-
 .../messages/peers/GetPeersResponse.java      |   7 +-
 10 files changed, 405 insertions(+), 236 deletions(-)
 create mode 100644 network/src/main/java/io/bitsquare/p2p/peers/PeerExchangeHandshake.java

diff --git a/core/src/main/java/io/bitsquare/trade/protocol/availability/OfferAvailabilityProtocol.java b/core/src/main/java/io/bitsquare/trade/protocol/availability/OfferAvailabilityProtocol.java
index bb1115ec52..0bd7e0dff0 100644
--- a/core/src/main/java/io/bitsquare/trade/protocol/availability/OfferAvailabilityProtocol.java
+++ b/core/src/main/java/io/bitsquare/trade/protocol/availability/OfferAvailabilityProtocol.java
@@ -134,13 +134,15 @@ public class OfferAvailabilityProtocol {
     }
 
     private void startTimeout() {
-        stopTimeout();
-
-        timeoutTimer = UserThread.runAfter(() -> {
-            log.warn("Timeout reached");
-            model.offer.setState(Offer.State.OFFERER_OFFLINE);
-            errorMessageHandler.handleErrorMessage("Timeout reached: Peer has not responded.");
-        }, TIMEOUT_SEC);
+        if (timeoutTimer == null) {
+            timeoutTimer = UserThread.runAfter(() -> {
+                log.warn("Timeout reached at " + this);
+                model.offer.setState(Offer.State.OFFERER_OFFLINE);
+                errorMessageHandler.handleErrorMessage("Timeout reached: Peer has not responded.");
+            }, TIMEOUT_SEC);
+        } else {
+            log.warn("timeoutTimer already created. That must not happen.");
+        }
     }
 
     private void stopTimeout() {
diff --git a/gui/src/main/java/io/bitsquare/gui/main/settings/network/NetworkSettingsView.fxml b/gui/src/main/java/io/bitsquare/gui/main/settings/network/NetworkSettingsView.fxml
index 7d31c43261..eefcb5963f 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/settings/network/NetworkSettingsView.fxml
+++ b/gui/src/main/java/io/bitsquare/gui/main/settings/network/NetworkSettingsView.fxml
@@ -38,8 +38,7 @@
 
     <Label fx:id="bitcoinPeersLabel" text="Connected peers:" GridPane.rowIndex="1"/>
     <TextArea fx:id="bitcoinPeersTextArea" GridPane.rowIndex="1" GridPane.columnIndex="1" GridPane.hgrow="ALWAYS"
-              editable="false" focusTraversable="false"/>
-
+              GridPane.vgrow="ALWAYS" editable="false" focusTraversable="false"/>
 
     <TitledGroupBg text="P2P network" GridPane.rowIndex="3" GridPane.rowSpan="5">
         <padding>
@@ -64,7 +63,7 @@
 
     <Label fx:id="p2PPeersLabel" text="Connected peers:" GridPane.rowIndex="4"/>
     <TextArea fx:id="p2PPeersTextArea" GridPane.rowIndex="4" GridPane.columnIndex="1" GridPane.hgrow="ALWAYS"
-              editable="false" focusTraversable="false"/>
+              GridPane.vgrow="ALWAYS" editable="false" focusTraversable="false"/>
 
     <columnConstraints>
         <ColumnConstraints hgrow="SOMETIMES" halignment="RIGHT" minWidth="200.0"/>
diff --git a/network/src/main/java/io/bitsquare/p2p/P2PService.java b/network/src/main/java/io/bitsquare/p2p/P2PService.java
index f60ecd8b6f..cfa9853e2e 100644
--- a/network/src/main/java/io/bitsquare/p2p/P2PService.java
+++ b/network/src/main/java/io/bitsquare/p2p/P2PService.java
@@ -110,12 +110,7 @@ public class P2PService implements SetupListener, MessageListener, ConnectionLis
         Log.traceCall();
 
         connectionNodeAddressListener = (observable, oldValue, newValue) -> {
-            Set<NodeAddress> nodeAddressesOfConfirmedConnections = networkNode.getNodeAddressesOfConfirmedConnections();
-            Set<Connection> allConfirmedConnections = networkNode.getConfirmedConnections();
-            log.info("nodeAddressesOfConfirmedConnections=" + nodeAddressesOfConfirmedConnections);
-            log.info("allConfirmedConnections=" + allConfirmedConnections);
-            log.info("Nr of connections: {} / {} (nodeAddressesOfConfirmedConnections / allConfirmedConnections)", nodeAddressesOfConfirmedConnections.size(), allConfirmedConnections.size());
-            UserThread.execute(() -> numConnectedPeers.set(nodeAddressesOfConfirmedConnections.size()));
+            UserThread.execute(() -> numConnectedPeers.set(networkNode.getNodeAddressesOfConfirmedConnections().size()));
         };
 
         networkNode = useLocalhost ? new LocalhostNetworkNode(port) : new TorNetworkNode(port, torDir);
@@ -265,7 +260,7 @@ public class P2PService implements SetupListener, MessageListener, ConnectionLis
         Optional<NodeAddress> seedNodeOfPreliminaryDataRequest = requestDataManager.getNodeOfPreliminaryDataRequest();
         checkArgument(seedNodeOfPreliminaryDataRequest.isPresent(),
                 "seedNodeOfPreliminaryDataRequest must be present");
-        peerExchangeManager.requestReportedPeers(seedNodeOfPreliminaryDataRequest.get());
+        peerExchangeManager.requestReportedPeersFromSeedNodes(seedNodeOfPreliminaryDataRequest.get());
 
         isBootstrapped = true;
         p2pServiceListeners.stream().forEach(P2PServiceListener::onBootstrapComplete);
diff --git a/network/src/main/java/io/bitsquare/p2p/peers/PeerExchangeHandshake.java b/network/src/main/java/io/bitsquare/p2p/peers/PeerExchangeHandshake.java
new file mode 100644
index 0000000000..816b37794e
--- /dev/null
+++ b/network/src/main/java/io/bitsquare/p2p/peers/PeerExchangeHandshake.java
@@ -0,0 +1,208 @@
+package io.bitsquare.p2p.peers;
+
+import com.google.common.util.concurrent.FutureCallback;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.SettableFuture;
+import io.bitsquare.app.Log;
+import io.bitsquare.common.UserThread;
+import io.bitsquare.p2p.Message;
+import io.bitsquare.p2p.NodeAddress;
+import io.bitsquare.p2p.network.Connection;
+import io.bitsquare.p2p.network.MessageListener;
+import io.bitsquare.p2p.network.NetworkNode;
+import io.bitsquare.p2p.peers.messages.peers.GetPeersRequest;
+import io.bitsquare.p2p.peers.messages.peers.GetPeersResponse;
+import org.jetbrains.annotations.NotNull;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Random;
+import java.util.Timer;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+public class PeerExchangeHandshake implements MessageListener {
+    private static final Logger log = LoggerFactory.getLogger(PeerExchangeHandshake.class);
+
+    ///////////////////////////////////////////////////////////////////////////////////////////
+    // Listener
+    ///////////////////////////////////////////////////////////////////////////////////////////
+
+    public interface Listener {
+        void onComplete();
+
+        void onFault(String errorMessage);
+    }
+
+
+    ///////////////////////////////////////////////////////////////////////////////////////////
+    // Class fields
+    ///////////////////////////////////////////////////////////////////////////////////////////
+
+    private final NetworkNode networkNode;
+    private final PeerManager peerManager;
+    private final Listener listener;
+    private final long nonce = new Random().nextLong();
+    private Timer timeoutTimer;
+
+
+    ///////////////////////////////////////////////////////////////////////////////////////////
+    // Constructor
+    ///////////////////////////////////////////////////////////////////////////////////////////
+
+    public PeerExchangeHandshake(NetworkNode networkNode, PeerManager peerManager, Listener listener) {
+        this.networkNode = networkNode;
+        this.peerManager = peerManager;
+        this.listener = listener;
+
+        networkNode.addMessageListener(this);
+    }
+
+    public void shutDown() {
+        Log.traceCall();
+        networkNode.removeMessageListener(this);
+        stopTimeoutTimer();
+    }
+
+
+    ///////////////////////////////////////////////////////////////////////////////////////////
+    // API
+    ///////////////////////////////////////////////////////////////////////////////////////////
+
+    public void requestReportedPeers(NodeAddress nodeAddress, List<NodeAddress> remainingNodeAddresses) {
+        Log.traceCall("nodeAddress=" + nodeAddress + " /  remainingNodeAddresses=" + remainingNodeAddresses);
+        checkNotNull(networkNode.getNodeAddress(), "My node address must not be null at requestReportedPeers");
+        checkArgument(timeoutTimer == null, "requestData must not be called twice.");
+
+        timeoutTimer = UserThread.runAfter(() -> {
+                    log.info("timeoutTimer called");
+                    peerManager.shutDownConnection(nodeAddress);
+                    shutDown();
+                    listener.onFault("A timeout occurred");
+                },
+                20, TimeUnit.SECONDS);
+
+        GetPeersRequest getPeersRequest = new GetPeersRequest(networkNode.getNodeAddress(), nonce,
+                getReportedPeers(nodeAddress));
+        SettableFuture<Connection> future = networkNode.sendMessage(nodeAddress,
+                getPeersRequest);
+        Futures.addCallback(future, new FutureCallback<Connection>() {
+            @Override
+            public void onSuccess(Connection connection) {
+                log.trace("Send " + getPeersRequest + " to " + nodeAddress + " succeeded.");
+            }
+
+            @Override
+            public void onFailure(@NotNull Throwable throwable) {
+                String errorMessage = "Sending getPeersRequest to " + nodeAddress +
+                        " failed. That is expected if the peer is offline. getPeersRequest=" + getPeersRequest + "." +
+                        "Exception: " + throwable.getMessage();
+                log.info(errorMessage);
+
+                peerManager.shutDownConnection(nodeAddress);
+                shutDown();
+                listener.onFault(errorMessage);
+            }
+        });
+    }
+
+    public void onGetPeersRequest(GetPeersRequest message, final Connection connection) {
+        checkArgument(timeoutTimer == null, "requestData must not be called twice.");
+
+        timeoutTimer = UserThread.runAfter(() -> {
+                    log.info("timeoutTimer called");
+                    peerManager.shutDownConnection(connection);
+                    shutDown();
+                    listener.onFault("A timeout occurred");
+                },
+                20, TimeUnit.SECONDS);
+
+        GetPeersRequest getPeersRequest = message;
+        HashSet<ReportedPeer> reportedPeers = getPeersRequest.reportedPeers;
+        StringBuilder result = new StringBuilder("Received peers:");
+        reportedPeers.stream().forEach(e -> result.append("\n").append(e));
+        log.trace(result.toString());
+
+        checkArgument(connection.getPeersNodeAddressOptional().isPresent(),
+                "The peers address must have been already set at the moment");
+        SettableFuture<Connection> future = networkNode.sendMessage(connection,
+                new GetPeersResponse(getPeersRequest.nonce,
+                        getReportedPeers(connection.getPeersNodeAddressOptional().get())));
+        Futures.addCallback(future, new FutureCallback<Connection>() {
+            @Override
+            public void onSuccess(Connection connection) {
+                log.trace("GetPeersResponse sent successfully");
+                shutDown();
+                listener.onComplete();
+            }
+
+            @Override
+            public void onFailure(@NotNull Throwable throwable) {
+                String errorMessage = "Sending getPeersRequest to " + connection +
+                        " failed. That is expected if the peer is offline. getPeersRequest=" + getPeersRequest + "." +
+                        "Exception: " + throwable.getMessage();
+                log.info(errorMessage);
+
+                peerManager.shutDownConnection(connection);
+                shutDown();
+                listener.onFault(errorMessage);
+            }
+        });
+        peerManager.addToReportedPeers(reportedPeers, connection);
+    }
+
+
+    ///////////////////////////////////////////////////////////////////////////////////////////
+    // MessageListener implementation
+    ///////////////////////////////////////////////////////////////////////////////////////////
+
+    @Override
+    public void onMessage(Message message, Connection connection) {
+        if (message instanceof GetPeersResponse) {
+            Log.traceCall(message.toString() + " / connection=" + connection);
+            GetPeersResponse getPeersResponse = (GetPeersResponse) message;
+            if (getPeersResponse.requestNonce == nonce) {
+                stopTimeoutTimer();
+
+                HashSet<ReportedPeer> reportedPeers = getPeersResponse.reportedPeers;
+                StringBuilder result = new StringBuilder("Received peers:");
+                reportedPeers.stream().forEach(e -> result.append("\n").append(e));
+                log.trace(result.toString());
+                peerManager.addToReportedPeers(reportedPeers, connection);
+
+                shutDown();
+                listener.onComplete();
+            } else {
+                log.debug("Nonce not matching. That happens if we get a response after a canceled handshake " +
+                                "(timeout). We drop that message. nonce={} / requestNonce={}",
+                        nonce, getPeersResponse.requestNonce);
+            }
+        }
+    }
+
+
+    ///////////////////////////////////////////////////////////////////////////////////////////
+    // Private
+    ///////////////////////////////////////////////////////////////////////////////////////////
+
+    private HashSet<ReportedPeer> getReportedPeers(NodeAddress receiverNodeAddress) {
+        return new HashSet<>(peerManager.getConnectedAndReportedPeers().stream()
+                .filter(e -> !peerManager.isSeedNode(e) &&
+                                !peerManager.isSelf(e) &&
+                                !e.nodeAddress.equals(receiverNodeAddress)
+                )
+                .collect(Collectors.toSet()));
+    }
+
+    private void stopTimeoutTimer() {
+        if (timeoutTimer != null) {
+            timeoutTimer.cancel();
+            timeoutTimer = null;
+        }
+    }
+}
diff --git a/network/src/main/java/io/bitsquare/p2p/peers/PeerExchangeManager.java b/network/src/main/java/io/bitsquare/p2p/peers/PeerExchangeManager.java
index d890fb00dc..3a3851ae61 100644
--- a/network/src/main/java/io/bitsquare/p2p/peers/PeerExchangeManager.java
+++ b/network/src/main/java/io/bitsquare/p2p/peers/PeerExchangeManager.java
@@ -1,9 +1,6 @@
 package io.bitsquare.p2p.peers;
 
-import com.google.common.util.concurrent.FutureCallback;
-import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.MoreExecutors;
-import com.google.common.util.concurrent.SettableFuture;
 import io.bitsquare.app.Log;
 import io.bitsquare.common.UserThread;
 import io.bitsquare.common.util.Utilities;
@@ -11,9 +8,6 @@ import io.bitsquare.p2p.Message;
 import io.bitsquare.p2p.NodeAddress;
 import io.bitsquare.p2p.network.*;
 import io.bitsquare.p2p.peers.messages.peers.GetPeersRequest;
-import io.bitsquare.p2p.peers.messages.peers.GetPeersResponse;
-import io.bitsquare.p2p.peers.messages.peers.PeerExchangeMessage;
-import org.jetbrains.annotations.NotNull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -32,7 +26,8 @@ public class PeerExchangeManager implements MessageListener, ConnectionListener
     private final PeerManager peerManager;
     private final Set<NodeAddress> seedNodeAddresses;
     private final ScheduledThreadPoolExecutor executor;
-    private Timer connectToMorePeersTimer, timeoutTimer, maintainConnectionsTimer;
+    private final Map<NodeAddress, PeerExchangeHandshake> peerExchangeHandshakeMap = new HashMap<>();
+    private Timer connectToMorePeersTimer, maintainConnectionsTimer;
 
 
     ///////////////////////////////////////////////////////////////////////////////////////////
@@ -55,7 +50,7 @@ public class PeerExchangeManager implements MessageListener, ConnectionListener
         networkNode.removeMessageListener(this);
         stopConnectToMorePeersTimer();
         stopMaintainConnectionsTimer();
-        stopTimeoutTimer();
+        peerExchangeHandshakeMap.values().stream().forEach(PeerExchangeHandshake::shutDown);
         MoreExecutors.shutdownAndAwaitTermination(executor, 500, TimeUnit.MILLISECONDS);
     }
 
@@ -64,12 +59,13 @@ public class PeerExchangeManager implements MessageListener, ConnectionListener
     // API
     ///////////////////////////////////////////////////////////////////////////////////////////
 
-    public void requestReportedPeers(NodeAddress nodeAddress) {
+    public void requestReportedPeersFromSeedNodes(NodeAddress nodeAddress) {
+        checkNotNull(networkNode.getNodeAddress(), "My node address must not be null at requestReportedPeers");
         ArrayList<NodeAddress> remainingNodeAddresses = new ArrayList<>(seedNodeAddresses);
         remainingNodeAddresses.remove(nodeAddress);
         requestReportedPeers(nodeAddress, remainingNodeAddresses);
 
-        long delay = new Random().nextInt(60) + 60 * 3; // 3-4 min. 
+        int delay = new Random().nextInt(60) + 60 * 4; // 4-5 min
         executor.scheduleAtFixedRate(() -> UserThread.execute(this::maintainConnections),
                 delay, delay, TimeUnit.SECONDS);
     }
@@ -87,11 +83,11 @@ public class PeerExchangeManager implements MessageListener, ConnectionListener
     public void onDisconnect(Reason reason, Connection connection) {
         // We use a timer to throttle if we get a series of disconnects
         // The more connections we have the more relaxed we are with a checkConnections
-        if (maintainConnectionsTimer == null)
-            maintainConnectionsTimer = UserThread.runAfter(this::maintainConnections,
-                    networkNode.getAllConnections().size() * 10, TimeUnit.SECONDS);
-
-
+        stopMaintainConnectionsTimer();
+        int size = networkNode.getAllConnections().size();
+        int delay = 10 + 2 * size * size; // 12 sec - 210 sec (3.5 min)
+        maintainConnectionsTimer = UserThread.runAfter(this::maintainConnections,
+                delay, TimeUnit.SECONDS);
     }
 
     @Override
@@ -105,45 +101,23 @@ public class PeerExchangeManager implements MessageListener, ConnectionListener
 
     @Override
     public void onMessage(Message message, Connection connection) {
-        if (message instanceof PeerExchangeMessage) {
-            Log.traceCall(message.toString());
-            if (message instanceof GetPeersRequest) {
-                HashSet<ReportedPeer> reportedPeers = ((GetPeersRequest) message).reportedPeers;
+        if (message instanceof GetPeersRequest) {
+            PeerExchangeHandshake peerExchangeHandshake = new PeerExchangeHandshake(networkNode,
+                    peerManager,
+                    new PeerExchangeHandshake.Listener() {
+                        @Override
+                        public void onComplete() {
+                            log.trace("PeerExchangeHandshake of inbound connection complete. Connection= {}",
+                                    connection);
+                        }
 
-                StringBuilder result = new StringBuilder("Received peers:");
-                reportedPeers.stream().forEach(e -> result.append("\n").append(e));
-                log.trace(result.toString());
-                
-                checkArgument(connection.getPeersNodeAddressOptional().isPresent(),
-                        "The peers address must have been already set at the moment");
-                SettableFuture<Connection> future = networkNode.sendMessage(connection,
-                        new GetPeersResponse(getReportedPeersHashSet(connection.getPeersNodeAddressOptional().get())));
-                Futures.addCallback(future, new FutureCallback<Connection>() {
-                    @Override
-                    public void onSuccess(Connection connection) {
-                        log.trace("GetPeersResponse sent successfully");
-                    }
-
-                    @Override
-                    public void onFailure(@NotNull Throwable throwable) {
-                        log.info("GetPeersResponse sending failed " + throwable.getMessage() +
-                                " Maybe the peer went offline.");
-                    }
-                });
-                peerManager.addToReportedPeers(reportedPeers, connection);
-            } else if (message instanceof GetPeersResponse) {
-                stopTimeoutTimer();
-
-                HashSet<ReportedPeer> reportedPeers = ((GetPeersResponse) message).reportedPeers;
-
-                StringBuilder result = new StringBuilder("Received peers:");
-                reportedPeers.stream().forEach(e -> result.append("\n").append(e));
-                log.trace(result.toString());
-
-                peerManager.addToReportedPeers(reportedPeers, connection);
-
-                connectToMorePeers();
-            }
+                        @Override
+                        public void onFault(String errorMessage) {
+                            log.trace("PeerExchangeHandshake of outbound connection failed. {} connection= {}",
+                                    errorMessage, connection);
+                        }
+                    });
+            peerExchangeHandshake.onGetPeersRequest((GetPeersRequest) message, connection);
         }
     }
 
@@ -154,82 +128,44 @@ public class PeerExchangeManager implements MessageListener, ConnectionListener
 
     private void requestReportedPeers(NodeAddress nodeAddress, List<NodeAddress> remainingNodeAddresses) {
         Log.traceCall("nodeAddress=" + nodeAddress + " /  remainingNodeAddresses=" + remainingNodeAddresses);
-        checkNotNull(networkNode.getNodeAddress(), "My node address must not be null at requestReportedPeers");
+        if (!peerExchangeHandshakeMap.containsKey(nodeAddress)) {
+            PeerExchangeHandshake peerExchangeHandshake = new PeerExchangeHandshake(networkNode,
+                    peerManager,
+                    new PeerExchangeHandshake.Listener() {
+                        @Override
+                        public void onComplete() {
+                            log.trace("PeerExchangeHandshake of outbound connection complete. nodeAddress= {}",
+                                    nodeAddress);
+                            peerExchangeHandshakeMap.remove(nodeAddress);
+                            connectToMorePeers();
+                        }
 
-        stopConnectToMorePeersTimer();
-        stopTimeoutTimer();
+                        @Override
+                        public void onFault(String errorMessage) {
+                            log.trace("PeerExchangeHandshake of outbound connection failed. {} nodeAddress= {}",
+                                    errorMessage, nodeAddress);
 
-        timeoutTimer = UserThread.runAfter(() -> {
-                    log.info("timeoutTimer called");
-                    handleError(nodeAddress, remainingNodeAddresses);
-                },
-                20, TimeUnit.SECONDS);
-
-        SettableFuture<Connection> future = networkNode.sendMessage(nodeAddress,
-                new GetPeersRequest(networkNode.getNodeAddress(), getReportedPeersHashSet(nodeAddress)));
-        Futures.addCallback(future, new FutureCallback<Connection>() {
-            @Override
-            public void onSuccess(Connection connection) {
-                log.trace("GetPeersRequest sent successfully");
-            }
-
-            @Override
-            public void onFailure(@NotNull Throwable throwable) {
-                log.info("Sending GetPeersRequest to " + nodeAddress + " failed. " +
-                        "That is expected if the peer is offline. " +
-                        "Exception:" + throwable.getMessage());
-                handleError(nodeAddress, remainingNodeAddresses);
-            }
-        });
-    }
-
-    private void connectToMorePeers() {
-        Log.traceCall();
-
-        stopConnectToMorePeersTimer();
-
-        if (!peerManager.hasSufficientConnections()) {
-            // We want to keep it sorted but avoid duplicates
-            List<NodeAddress> list = new ArrayList<>(getFilteredAndSortedList(peerManager.getReportedPeers(), new ArrayList<>()));
-            list.addAll(getFilteredAndSortedList(peerManager.getPersistedPeers(), list));
-            list.addAll(seedNodeAddresses.stream()
-                    .filter(e -> !list.contains(e) &&
-                            !peerManager.isSelf(e) &&
-                            !peerManager.isConfirmed(e))
-                    .collect(Collectors.toSet()));
-            log.trace("Sorted and filtered list: list=" + list);
-            if (!list.isEmpty()) {
-                NodeAddress nextCandidate = list.get(0);
-                list.remove(nextCandidate);
-                requestReportedPeers(nextCandidate, list);
-            } else {
-                log.info("No more peers are available for requestReportedPeers.");
-            }
+                            peerExchangeHandshakeMap.remove(nodeAddress);
+                            if (!remainingNodeAddresses.isEmpty()) {
+                                log.info("There are remaining nodes available for requesting peers. " +
+                                        "We will try getReportedPeers again.");
+                                requestReportedPeersFromRandomPeer(remainingNodeAddresses);
+                            } else {
+                                log.info("There is no remaining node available for requesting peers. " +
+                                        "That is expected if no other node is online.\n" +
+                                        "We will try again after a random pause.");
+                                if (connectToMorePeersTimer == null)
+                                    connectToMorePeersTimer = UserThread.runAfterRandomDelay(
+                                            PeerExchangeManager.this::connectToMorePeers, 20, 30);
+                            }
+                        }
+                    });
+            peerExchangeHandshakeMap.put(nodeAddress, peerExchangeHandshake);
+            peerExchangeHandshake.requestReportedPeers(nodeAddress, remainingNodeAddresses);
         } else {
-            log.info("We have already sufficient connections.");
-        }
-    }
-
-    private void handleError(NodeAddress peersNodeAddress, List<NodeAddress> remainingNodeAddresses) {
-        Log.traceCall("peersNodeAddress=" + peersNodeAddress + " /  remainingNodeAddresses=" + remainingNodeAddresses);
-
-        stopTimeoutTimer();
-
-        // In case a shutdown was not triggered already by the error we close that connection 
-        // if it is not a DIRECT_MSG_PEER
-        peerManager.shutDownConnection(peersNodeAddress);
-
-        if (!remainingNodeAddresses.isEmpty()) {
-            log.info("There are remaining nodes available for requesting peers. " +
-                    "We will try getReportedPeers again.");
-            requestReportedPeersFromRandomPeer(remainingNodeAddresses);
-        } else {
-            log.info("There is no remaining node available for requesting peers. " +
-                    "That is expected if no other node is online.\n" +
-                    "We will try to use reported peers (if no available we use persisted peers) " +
-                    "and try again to request peers from our seed nodes after a random pause.");
-            if (connectToMorePeersTimer == null)
-                connectToMorePeersTimer = UserThread.runAfterRandomDelay(this::connectToMorePeers, 20, 30);
+            log.trace("We have started already a peerExchangeHandshake to peer. " +
+                    "That can happen by the timers calls. We ignore that call. " +
+                    "nodeAddress=" + nodeAddress);
         }
     }
 
@@ -256,20 +192,48 @@ public class PeerExchangeManager implements MessageListener, ConnectionListener
             connectToMorePeers();
         }
 
-        // Use all outbound connections for updating reported peers and make sure we keep the connection alive
+        // Use all outbound connections older than 5 min. for updating reported peers and make sure we keep the connection alive
         // Inbound connections should be maintained be the requesting peer
         confirmedConnections.stream()
                 .filter(c -> c.getPeersNodeAddressOptional().isPresent() &&
-                        c instanceof OutboundConnection).
-                forEach(c -> UserThread.runAfterRandomDelay(() ->
-                        requestReportedPeers(c.getPeersNodeAddressOptional().get(), new ArrayList<>())
+                        c instanceof OutboundConnection &&
+                        new Date().getTime() - c.getLastActivityDate().getTime() > 5 * 60 * 1000)
+                .forEach(c -> UserThread.runAfterRandomDelay(() -> {
+                    log.trace("Call requestReportedPeers from maintainConnections");
+                    requestReportedPeers(c.getPeersNodeAddressOptional().get(), new ArrayList<>());
+                }
                         , 3, 5));
     }
 
+    private void connectToMorePeers() {
+        Log.traceCall();
 
-    ///////////////////////////////////////////////////////////////////////////////////////////
-    // Utils
-    ///////////////////////////////////////////////////////////////////////////////////////////
+        stopConnectToMorePeersTimer();
+
+        if (!peerManager.hasSufficientConnections()) {
+            // We create a new list of not connected candidates
+            // 1. reported sorted by most recent lastActivityDate
+            // 2. persisted sorted by most recent lastActivityDate
+            // 3. seenNodes
+            List<NodeAddress> list = new ArrayList<>(getFilteredAndSortedList(peerManager.getReportedPeers(), new ArrayList<>()));
+            list.addAll(getFilteredAndSortedList(peerManager.getPersistedPeers(), list));
+            list.addAll(seedNodeAddresses.stream()
+                    .filter(e -> !list.contains(e) &&
+                            !peerManager.isSelf(e) &&
+                            !peerManager.isConfirmed(e))
+                    .collect(Collectors.toSet()));
+            log.trace("Sorted and filtered list: list=" + list);
+            if (!list.isEmpty()) {
+                NodeAddress nextCandidate = list.get(0);
+                list.remove(nextCandidate);
+                requestReportedPeers(nextCandidate, list);
+            } else {
+                log.info("No more peers are available for requestReportedPeers.");
+            }
+        } else {
+            log.info("We have already sufficient connections.");
+        }
+    }
 
     // sorted by most recent lastActivityDate
     private List<NodeAddress> getFilteredAndSortedList(Set<ReportedPeer> set, List<NodeAddress> list) {
@@ -291,15 +255,6 @@ public class PeerExchangeManager implements MessageListener, ConnectionListener
         requestReportedPeers(nextCandidate, remainingNodeAddresses);
     }
 
-    private HashSet<ReportedPeer> getReportedPeersHashSet(NodeAddress receiverNodeAddress) {
-        return new HashSet<>(peerManager.getConnectedAndReportedPeers().stream()
-                .filter(e -> !peerManager.isSeedNode(e) &&
-                                !peerManager.isSelf(e) &&
-                                !e.nodeAddress.equals(receiverNodeAddress)
-                )
-                .collect(Collectors.toSet()));
-    }
-
     private void stopConnectToMorePeersTimer() {
         if (connectToMorePeersTimer != null) {
             connectToMorePeersTimer.cancel();
@@ -313,11 +268,4 @@ public class PeerExchangeManager implements MessageListener, ConnectionListener
             maintainConnectionsTimer = null;
         }
     }
-
-    private void stopTimeoutTimer() {
-        if (timeoutTimer != null) {
-            timeoutTimer.cancel();
-            timeoutTimer = null;
-        }
-    }
 }
diff --git a/network/src/main/java/io/bitsquare/p2p/peers/PeerManager.java b/network/src/main/java/io/bitsquare/p2p/peers/PeerManager.java
index 9a1e76aa7e..21c8a7e0e3 100644
--- a/network/src/main/java/io/bitsquare/p2p/peers/PeerManager.java
+++ b/network/src/main/java/io/bitsquare/p2p/peers/PeerManager.java
@@ -178,9 +178,8 @@ public class PeerManager implements ConnectionListener, MessageListener {
                                 "MAX_CONNECTIONS_HIGH_PRIORITY limit of {}", MAX_CONNECTIONS_EXTENDED_2);
                         if (size > MAX_CONNECTIONS_EXTENDED_2) {
                             log.info("Lets try to remove any connection which is not of type DIRECT_MSG_PEER.");
-                            // All expect DIRECT_MSG_PEER type connections
+                            // All connections
                             candidates = allConnections.stream()
-                                    .filter(e -> e.getPeerType() != Connection.PeerType.DIRECT_MSG_PEER)
                                     .collect(Collectors.toList());
                         }
                     }
@@ -436,10 +435,11 @@ public class PeerManager implements ConnectionListener, MessageListener {
     }
 
     private void printConnectedPeers() {
-        if (!networkNode.getNodeAddressesOfConfirmedConnections().isEmpty()) {
+        if (!networkNode.getConfirmedConnections().isEmpty()) {
             StringBuilder result = new StringBuilder("\n\n------------------------------------------------------------\n" +
                     "Connected peers for node " + networkNode.getNodeAddress() + ":");
-            networkNode.getNodeAddressesOfConfirmedConnections().stream().forEach(e -> result.append("\n").append(e));
+            networkNode.getConfirmedConnections().stream().forEach(e -> result.append("\n")
+                    .append(e.getPeersNodeAddressOptional().get()).append(" ").append(e.getPeerType()));
             result.append("\n------------------------------------------------------------\n");
             log.info(result.toString());
         }
diff --git a/network/src/main/java/io/bitsquare/p2p/peers/RequestDataHandshake.java b/network/src/main/java/io/bitsquare/p2p/peers/RequestDataHandshake.java
index b12f1154eb..ee71870aff 100644
--- a/network/src/main/java/io/bitsquare/p2p/peers/RequestDataHandshake.java
+++ b/network/src/main/java/io/bitsquare/p2p/peers/RequestDataHandshake.java
@@ -50,7 +50,7 @@ public class RequestDataHandshake implements MessageListener {
     private final PeerManager peerManager;
     private final Listener listener;
     private Timer timeoutTimer;
-    private long requestNonce;
+    private final long nonce = new Random().nextLong();
 
 
     ///////////////////////////////////////////////////////////////////////////////////////////
@@ -69,22 +69,19 @@ public class RequestDataHandshake implements MessageListener {
 
     public void shutDown() {
         Log.traceCall();
-
         networkNode.removeMessageListener(this);
-
         stopTimeoutTimer();
     }
 
+
     ///////////////////////////////////////////////////////////////////////////////////////////
     // API
     ///////////////////////////////////////////////////////////////////////////////////////////
 
     public void requestData(NodeAddress nodeAddress) {
         Log.traceCall("nodeAddress=" + nodeAddress);
-
-        stopTimeoutTimer();
-
         checkArgument(timeoutTimer == null, "requestData must not be called twice.");
+
         timeoutTimer = UserThread.runAfter(() -> {
                     log.info("timeoutTimer called");
                     peerManager.shutDownConnection(nodeAddress);
@@ -94,11 +91,10 @@ public class RequestDataHandshake implements MessageListener {
                 10, TimeUnit.SECONDS);
 
         Message dataRequest;
-        requestNonce = new Random().nextLong();
         if (networkNode.getNodeAddress() == null)
-            dataRequest = new PreliminaryDataRequest(requestNonce);
+            dataRequest = new PreliminaryDataRequest(nonce);
         else
-            dataRequest = new UpdateDataRequest(networkNode.getNodeAddress(), requestNonce);
+            dataRequest = new UpdateDataRequest(networkNode.getNodeAddress(), nonce);
 
         log.info("We send a {} to peer {}. ", dataRequest.getClass().getSimpleName(), nodeAddress);
 
@@ -106,14 +102,14 @@ public class RequestDataHandshake implements MessageListener {
         Futures.addCallback(future, new FutureCallback<Connection>() {
             @Override
             public void onSuccess(@Nullable Connection connection) {
-                log.trace("Send DataRequest to " + nodeAddress + " succeeded.");
+                log.trace("Send " + dataRequest + " to " + nodeAddress + " succeeded.");
             }
 
             @Override
             public void onFailure(@NotNull Throwable throwable) {
-                String errorMessage = "Sending " + dataRequest.getClass().getSimpleName() + " to " + nodeAddress +
-                        " failed. That is expected if the peer is offline. " +
-                        "Exception:" + throwable.getMessage();
+                String errorMessage = "Sending dataRequest to " + nodeAddress +
+                        " failed. That is expected if the peer is offline. dataRequest=" + dataRequest + "." +
+                        "Exception: " + throwable.getMessage();
                 log.info(errorMessage);
 
                 peerManager.shutDownConnection(nodeAddress);
@@ -123,43 +119,54 @@ public class RequestDataHandshake implements MessageListener {
         });
     }
 
+    public void onDataRequest(Message message, final Connection connection) {
+        Log.traceCall(message.toString() + " / connection=" + connection);
+
+        checkArgument(timeoutTimer == null, "requestData must not be called twice.");
+        timeoutTimer = UserThread.runAfter(() -> {
+                    log.info("timeoutTimer called");
+                    peerManager.shutDownConnection(connection);
+                    shutDown();
+                    listener.onFault("A timeout occurred");
+                },
+                10, TimeUnit.SECONDS);
+
+        DataRequest dataRequest = (DataRequest) message;
+        DataResponse dataResponse = new DataResponse(new HashSet<>(dataStorage.getMap().values()), dataRequest.getNonce());
+        SettableFuture<Connection> future = networkNode.sendMessage(connection, dataResponse);
+        Futures.addCallback(future, new FutureCallback<Connection>() {
+            @Override
+            public void onSuccess(Connection connection) {
+                log.trace("Send DataResponse to {} succeeded. dataResponse={}",
+                        connection.getPeersNodeAddressOptional(), dataResponse);
+                shutDown();
+                listener.onComplete();
+            }
+
+            @Override
+            public void onFailure(@NotNull Throwable throwable) {
+                String errorMessage = "Sending dataRequest to " + connection +
+                        " failed. That is expected if the peer is offline. dataRequest=" + dataRequest + "." +
+                        "Exception: " + throwable.getMessage();
+                log.info(errorMessage);
+
+                peerManager.shutDownConnection(connection);
+                shutDown();
+                listener.onFault(errorMessage);
+            }
+        });
+    }
+
     ///////////////////////////////////////////////////////////////////////////////////////////
     // MessageListener implementation
     ///////////////////////////////////////////////////////////////////////////////////////////
 
     @Override
     public void onMessage(Message message, Connection connection) {
-        if (message instanceof DataRequest) {
-            Log.traceCall(message.toString());
-            DataRequest dataRequest = (DataRequest) message;
-            DataResponse dataResponse = new DataResponse(new HashSet<>(dataStorage.getMap().values()), dataRequest.getNonce());
-            SettableFuture<Connection> future = networkNode.sendMessage(connection, dataResponse);
-            Futures.addCallback(future, new FutureCallback<Connection>() {
-                @Override
-                public void onSuccess(Connection connection) {
-                    log.trace("Send DataResponse to {} succeeded. dataResponse={}",
-                            connection.getPeersNodeAddressOptional(), dataResponse);
-                    shutDown();
-                    listener.onComplete();
-                }
-
-                @Override
-                public void onFailure(@NotNull Throwable throwable) {
-                    String errorMessage = "Send DataResponse to " + connection.getPeersNodeAddressOptional() + " failed. " +
-                            "That is expected if the peer went offline. " +
-                            "Exception:" + throwable.getMessage();
-                    log.info(errorMessage);
-
-                    peerManager.shutDownConnection(connection);
-                    shutDown();
-                    listener.onFault(errorMessage);
-                }
-            });
-        } else if (message instanceof DataResponse) {
+        if (message instanceof DataResponse) {
+            Log.traceCall(message.toString() + " / connection=" + connection);
             DataResponse dataResponse = (DataResponse) message;
-            if (dataResponse.requestNonce == requestNonce) {
-                Log.traceCall(message.toString());
-
+            if (dataResponse.requestNonce == nonce) {
                 stopTimeoutTimer();
 
                 // connection.getPeersNodeAddressOptional() is not present at the first call
@@ -168,12 +175,21 @@ public class RequestDataHandshake implements MessageListener {
                     ((DataResponse) message).dataSet.stream()
                             .forEach(e -> dataStorage.add(e, peersNodeAddress));
                 });
+
                 shutDown();
                 listener.onComplete();
+            } else {
+                log.debug("Nonce not matching. That happens if we get a response after a canceled handshake " +
+                                "(timeout). We drop that message. nonce={} / requestNonce={}",
+                        nonce, dataResponse.requestNonce);
             }
         }
     }
 
+    ///////////////////////////////////////////////////////////////////////////////////////////
+    // Private
+    ///////////////////////////////////////////////////////////////////////////////////////////
+
     private void stopTimeoutTimer() {
         if (timeoutTimer != null) {
             timeoutTimer.cancel();
diff --git a/network/src/main/java/io/bitsquare/p2p/peers/RequestDataManager.java b/network/src/main/java/io/bitsquare/p2p/peers/RequestDataManager.java
index 86203a2826..dd68552603 100644
--- a/network/src/main/java/io/bitsquare/p2p/peers/RequestDataManager.java
+++ b/network/src/main/java/io/bitsquare/p2p/peers/RequestDataManager.java
@@ -49,7 +49,6 @@ public class RequestDataManager implements MessageListener {
     private final Listener listener;
 
     private final Map<NodeAddress, RequestDataHandshake> requestDataHandshakeMap = new HashMap<>();
-
     private Optional<NodeAddress> nodeOfPreliminaryDataRequest = Optional.empty();
     private Timer requestDataTimer;
     private boolean dataUpdateRequested;
@@ -64,20 +63,17 @@ public class RequestDataManager implements MessageListener {
         this.networkNode = networkNode;
         this.dataStorage = dataStorage;
         this.peerManager = peerManager;
-        checkArgument(!seedNodeAddresses.isEmpty(), "seedNodeAddresses must not be empty.");
         this.seedNodeAddresses = new HashSet<>(seedNodeAddresses);
         this.listener = listener;
 
+        checkArgument(!seedNodeAddresses.isEmpty(), "seedNodeAddresses must not be empty.");
         networkNode.addMessageListener(this);
     }
 
     public void shutDown() {
         Log.traceCall();
-
         stopRequestDataTimer();
-
         networkNode.removeMessageListener(this);
-
         requestDataHandshakeMap.values().stream().forEach(RequestDataHandshake::shutDown);
     }
 
@@ -88,7 +84,10 @@ public class RequestDataManager implements MessageListener {
 
     public void requestPreliminaryData() {
         Log.traceCall();
-        requestDataFromRandomPeer(new ArrayList<>(seedNodeAddresses));
+        ArrayList<NodeAddress> nodeAddresses = new ArrayList<>(seedNodeAddresses);
+        NodeAddress nextCandidate = nodeAddresses.get(0);
+        nodeAddresses.remove(nextCandidate);
+        requestData(nextCandidate, nodeAddresses);
     }
 
     public void requestUpdatesData() {
@@ -113,8 +112,6 @@ public class RequestDataManager implements MessageListener {
     @Override
     public void onMessage(Message message, Connection connection) {
         if (message instanceof DataRequest) {
-            Log.traceCall(message.toString());
-            log.trace("Received {} at {}", message.getClass().getSimpleName(), connection);
             RequestDataHandshake requestDataHandshake = new RequestDataHandshake(networkNode, dataStorage, peerManager,
                     new RequestDataHandshake.Listener() {
                         @Override
@@ -125,11 +122,11 @@ public class RequestDataManager implements MessageListener {
 
                         @Override
                         public void onFault(String errorMessage) {
-                            log.info("RequestDataHandshake of inbound connection failed. Connection= {}",
+                            log.trace("RequestDataHandshake of inbound connection failed. {} Connection= {}",
                                     errorMessage, connection);
                         }
                     });
-            requestDataHandshake.onMessage(message, connection);
+            requestDataHandshake.onDataRequest(message, connection);
         }
     }
 
@@ -138,21 +135,15 @@ public class RequestDataManager implements MessageListener {
     // Private
     ///////////////////////////////////////////////////////////////////////////////////////////
 
-    private void requestDataFromRandomPeer(List<NodeAddress> nodeAddresses) {
-        Log.traceCall("remainingNodeAddresses=" + nodeAddresses);
-        NodeAddress nextCandidate = nodeAddresses.get(new Random().nextInt(nodeAddresses.size()));
-        nodeAddresses.remove(nextCandidate);
-        requestData(nextCandidate, nodeAddresses);
-    }
-
     private void requestData(NodeAddress nodeAddress, List<NodeAddress> remainingNodeAddresses) {
         Log.traceCall("nodeAddress=" + nodeAddress + " /  remainingNodeAddresses=" + remainingNodeAddresses);
-
         if (!requestDataHandshakeMap.containsKey(nodeAddress)) {
             RequestDataHandshake requestDataHandshake = new RequestDataHandshake(networkNode, dataStorage, peerManager,
                     new RequestDataHandshake.Listener() {
                         @Override
                         public void onComplete() {
+                            log.trace("RequestDataHandshake of outbound connection complete. nodeAddress= {}",
+                                    nodeAddress);
                             stopRequestDataTimer();
 
                             // need to remove before listeners are notified as they cause the update call
@@ -175,10 +166,14 @@ public class RequestDataManager implements MessageListener {
 
                         @Override
                         public void onFault(String errorMessage) {
+                            log.trace("RequestDataHandshake of outbound connection failed. {} nodeAddress= {}",
+                                    errorMessage, nodeAddress);
                             if (!remainingNodeAddresses.isEmpty()) {
                                 log.info("There are remaining nodes available for requesting data. " +
                                         "We will try requestDataFromPeers again.");
-                                requestDataFromRandomPeer(remainingNodeAddresses);
+                                NodeAddress nextCandidate = remainingNodeAddresses.get(0);
+                                remainingNodeAddresses.remove(nextCandidate);
+                                requestData(nextCandidate, remainingNodeAddresses);
                             } else {
                                 log.info("There is no remaining node available for requesting data. " +
                                         "That is expected if no other node is online.\n" +
@@ -219,7 +214,7 @@ public class RequestDataManager implements MessageListener {
             requestDataHandshakeMap.put(nodeAddress, requestDataHandshake);
             requestDataHandshake.requestData(nodeAddress);
         } else {
-            log.warn("We have started already a DataRequest request to peer. " + nodeAddress);
+            log.warn("We have started already a requestDataHandshake to peer. " + nodeAddress);
         }
     }
 
diff --git a/network/src/main/java/io/bitsquare/p2p/peers/messages/peers/GetPeersRequest.java b/network/src/main/java/io/bitsquare/p2p/peers/messages/peers/GetPeersRequest.java
index 667eedc7b9..31dfc322d4 100644
--- a/network/src/main/java/io/bitsquare/p2p/peers/messages/peers/GetPeersRequest.java
+++ b/network/src/main/java/io/bitsquare/p2p/peers/messages/peers/GetPeersRequest.java
@@ -12,10 +12,12 @@ public final class GetPeersRequest extends PeerExchangeMessage implements Sender
     private static final long serialVersionUID = Version.NETWORK_PROTOCOL_VERSION;
 
     private final NodeAddress senderNodeAddress;
+    public long nonce;
     public final HashSet<ReportedPeer> reportedPeers;
 
-    public GetPeersRequest(NodeAddress senderNodeAddress, HashSet<ReportedPeer> reportedPeers) {
+    public GetPeersRequest(NodeAddress senderNodeAddress, long nonce, HashSet<ReportedPeer> reportedPeers) {
         this.senderNodeAddress = senderNodeAddress;
+        this.nonce = nonce;
         this.reportedPeers = reportedPeers;
     }
 
@@ -28,6 +30,7 @@ public final class GetPeersRequest extends PeerExchangeMessage implements Sender
     public String toString() {
         return "GetPeersRequest{" +
                 "senderNodeAddress=" + senderNodeAddress +
+                ", requestNonce=" + nonce +
                 ", reportedPeers=" + reportedPeers +
                 super.toString() + "} ";
     }
diff --git a/network/src/main/java/io/bitsquare/p2p/peers/messages/peers/GetPeersResponse.java b/network/src/main/java/io/bitsquare/p2p/peers/messages/peers/GetPeersResponse.java
index bd5d3e5bca..79d56a589d 100644
--- a/network/src/main/java/io/bitsquare/p2p/peers/messages/peers/GetPeersResponse.java
+++ b/network/src/main/java/io/bitsquare/p2p/peers/messages/peers/GetPeersResponse.java
@@ -9,16 +9,19 @@ public final class GetPeersResponse extends PeerExchangeMessage {
     // That object is sent over the wire, so we need to take care of version compatibility.
     private static final long serialVersionUID = Version.NETWORK_PROTOCOL_VERSION;
 
+    public final long requestNonce;
     public final HashSet<ReportedPeer> reportedPeers;
 
-    public GetPeersResponse(HashSet<ReportedPeer> reportedPeers) {
+    public GetPeersResponse(long requestNonce, HashSet<ReportedPeer> reportedPeers) {
+        this.requestNonce = requestNonce;
         this.reportedPeers = reportedPeers;
     }
 
     @Override
     public String toString() {
         return "GetPeersResponse{" +
-                "reportedPeers=" + reportedPeers +
+                "requestNonce=" + requestNonce +
+                ", reportedPeers=" + reportedPeers +
                 super.toString() + "} ";
     }
 }