diff --git a/src/main/java/mpo/dayon/assistant/control/ControlEngine.java b/src/main/java/mpo/dayon/assistant/control/ControlEngine.java
index 3ed9159b..dadd4718 100644
--- a/src/main/java/mpo/dayon/assistant/control/ControlEngine.java
+++ b/src/main/java/mpo/dayon/assistant/control/ControlEngine.java
@@ -65,7 +65,7 @@ protected void execute() {
 		});
 	}
 	
-	private int getActingMouseButton(final int button) {
+	private static int getActingMouseButton(final int button) {
 		if (MouseEvent.BUTTON1 == button) {
 			return NetworkMouseControlMessage.BUTTON1;
 		}
@@ -91,7 +91,7 @@ protected void execute() {
 	/**
 	 * Fix missing pair'd PRESSED event from RELEASED
 	 */
-	private final HashMap<Integer, Character> pressedKeys = new HashMap<>();
+	private final HashMap<Integer, Character> pressedKeys = new HashMap<>(4);
 
 	/**
 	 * From AWT thread (!)
diff --git a/src/main/java/mpo/dayon/assistant/gui/Assistant.java b/src/main/java/mpo/dayon/assistant/gui/Assistant.java
index 151fc143..87495627 100644
--- a/src/main/java/mpo/dayon/assistant/gui/Assistant.java
+++ b/src/main/java/mpo/dayon/assistant/gui/Assistant.java
@@ -62,8 +62,6 @@ public class Assistant implements ClipboardOwner {
 
     private final NetworkAssistantEngine networkEngine;
 
-    private final ClipboardDispatcher clipboardDispatcher;
-
     private BitCounter receivedBitCounter;
 
     private TileCounter receivedTileCounter;
@@ -145,7 +143,6 @@ public Assistant(String tokenServerUrl, String language) {
             Log.warn("Could not set the [" + lnf + "] L&F!", ex);
         }
         initGui();
-        clipboardDispatcher = new ClipboardDispatcher();
     }
 
     private void initGui() {
@@ -306,7 +303,7 @@ public void actionPerformed(ActionEvent ev) {
     }
 
     private void sendLocalClipboard() {
-        clipboardDispatcher.sendClipboard(networkEngine, frame, this);
+        ClipboardDispatcher.sendClipboard(networkEngine, frame, this);
     }
 
     /**
@@ -411,7 +408,7 @@ private void updateCaptureConfiguration(CaptureEngineConfiguration newCaptureEng
         }
     }
 
-    private Gray8Bits toGrayLevel(int value) {
+    private static Gray8Bits toGrayLevel(int value) {
         return Gray8Bits.values()[6 - value];
     }
 
@@ -504,7 +501,7 @@ public void actionPerformed(ActionEvent ev) {
         return configure;
     }
 
-    private String validatePurgeValue(JTextField purgeSizeTf, int maxValue) {
+    private static String validatePurgeValue(JTextField purgeSizeTf, int maxValue) {
         final String purge = purgeSizeTf.getText();
         if (purge.isEmpty()) {
             return translate("compression.cache.purge.msg1");
@@ -708,7 +705,7 @@ public boolean isUpnpEnabled() {
         synchronized (upnpEnabledLOCK) {
             while (upnpEnabled == null) {
                 try {
-                    upnpEnabledLOCK.wait();
+                    upnpEnabledLOCK.wait(5000);
                 } catch (InterruptedException e) {
                     Log.warn("Swallowed", e);
                     Thread.currentThread().interrupt();
diff --git a/src/main/java/mpo/dayon/assistant/gui/AssistantConfiguration.java b/src/main/java/mpo/dayon/assistant/gui/AssistantConfiguration.java
index 7c45d3ac..1290a6d1 100644
--- a/src/main/java/mpo/dayon/assistant/gui/AssistantConfiguration.java
+++ b/src/main/java/mpo/dayon/assistant/gui/AssistantConfiguration.java
@@ -41,7 +41,7 @@ public boolean equals(Object o) {
 			return false;
 		}
 		final AssistantConfiguration that = (AssistantConfiguration) o;
-		return language.equals(that.getLanguage());
+		return language.equals(that.language);
 	}
 
 	@Override
diff --git a/src/main/java/mpo/dayon/assistant/gui/AssistantFrame.java b/src/main/java/mpo/dayon/assistant/gui/AssistantFrame.java
index a4918dc1..69949580 100644
--- a/src/main/java/mpo/dayon/assistant/gui/AssistantFrame.java
+++ b/src/main/java/mpo/dayon/assistant/gui/AssistantFrame.java
@@ -280,7 +280,7 @@ private JTabbedPane createTabbedPane() {
         return tabbedPane;
     }
 
-    private Component createTokenButton(Action tokenAction) {
+    private static Component createTokenButton(Action tokenAction) {
         String token = (String) tokenAction.getValue("token");
         JButton button = createButton(tokenAction);
         if (token != null) {
@@ -290,7 +290,7 @@ private Component createTokenButton(Action tokenAction) {
         return button;
     }
 
-    private StatusBar createStatusBar(ArrayList<Counter<?>> counters) {
+    private static StatusBar createStatusBar(ArrayList<Counter<?>> counters) {
         final StatusBar statusBar = new StatusBar();
         final Component horizontalStrut = Box.createHorizontalStrut(10);
         statusBar.add(horizontalStrut);
diff --git a/src/main/java/mpo/dayon/assistant/network/NetworkAssistantEngine.java b/src/main/java/mpo/dayon/assistant/network/NetworkAssistantEngine.java
index 13bfd914..3243fe6b 100644
--- a/src/main/java/mpo/dayon/assistant/network/NetworkAssistantEngine.java
+++ b/src/main/java/mpo/dayon/assistant/network/NetworkAssistantEngine.java
@@ -93,7 +93,7 @@ public void cancel() {
         fireOnDisconnecting();
     }
 
-    public void manageRouterPorts(int oldPort, int newPort) {
+    public static void manageRouterPorts(int oldPort, int newPort) {
         if (!UPnP.isUPnPAvailable()) {
             return;
         }
diff --git a/src/main/java/mpo/dayon/assistant/network/NetworkAssistantEngineConfiguration.java b/src/main/java/mpo/dayon/assistant/network/NetworkAssistantEngineConfiguration.java
index ca47fe91..3bdc8814 100644
--- a/src/main/java/mpo/dayon/assistant/network/NetworkAssistantEngineConfiguration.java
+++ b/src/main/java/mpo/dayon/assistant/network/NetworkAssistantEngineConfiguration.java
@@ -60,7 +60,7 @@ public boolean equals(Object o) {
 
 		final NetworkAssistantEngineConfiguration that = (NetworkAssistantEngineConfiguration) o;
 
-		return port == that.getPort() && tokenServerUrl.equals(that.getTokenServerUrl());
+		return port == that.port && tokenServerUrl.equals(that.tokenServerUrl);
 	}
 
 	@Override
diff --git a/src/main/java/mpo/dayon/assistant/utils/NetworkUtilities.java b/src/main/java/mpo/dayon/assistant/utils/NetworkUtilities.java
index b52ead55..7f4c2236 100644
--- a/src/main/java/mpo/dayon/assistant/utils/NetworkUtilities.java
+++ b/src/main/java/mpo/dayon/assistant/utils/NetworkUtilities.java
@@ -11,7 +11,7 @@
 
 public interface NetworkUtilities {
 	static List<String> getInetAddresses() {
-		final List<String> addresses = new ArrayList<>();
+		final List<String> addresses = new ArrayList<>(8);
 
 		try {
 			InetAddress loopback = null;
diff --git a/src/main/java/mpo/dayon/assisted/gui/Assisted.java b/src/main/java/mpo/dayon/assisted/gui/Assisted.java
index 9b9cc43c..67b4a0ac 100644
--- a/src/main/java/mpo/dayon/assisted/gui/Assisted.java
+++ b/src/main/java/mpo/dayon/assisted/gui/Assisted.java
@@ -20,6 +20,7 @@
 import mpo.dayon.common.gui.common.ImageUtilities;
 import mpo.dayon.common.log.Log;
 import mpo.dayon.common.network.ClipboardDispatcher;
+import mpo.dayon.common.network.NetworkEngine;
 import mpo.dayon.common.network.message.*;
 
 import javax.swing.*;
@@ -55,8 +56,6 @@ public class Assisted implements Subscriber, ClipboardOwner {
 
     private NetworkAssistedEngine networkEngine;
 
-    private final ClipboardDispatcher clipboardDispatcher;
-
     private boolean coldStart = true;
 
     private CaptureEngineConfiguration captureEngineConfiguration;
@@ -84,7 +83,6 @@ public Assisted(String tokenServerUrl) {
         } catch (Exception ex) {
             Log.warn(format("Could not set the L&F [%s]", lnf), ex);
         }
-        clipboardDispatcher = new ClipboardDispatcher();
     }
 
     /**
@@ -171,14 +169,14 @@ private boolean requestConnectionSettings() {
         return ok;
     }
 
-    private String validateIpAddress(String ipAddress) {
+    private static String validateIpAddress(String ipAddress) {
         if (ipAddress.isEmpty()) {
             return translate("connection.settings.emptyIpAddress");
         }
         return isValidIpAddressOrHostName(ipAddress.trim()) ? null : translate("connection.settings.invalidIpAddress");
     }
 
-    private String validatePortNumber(String portNumber) {
+    private static String validatePortNumber(String portNumber) {
         if (portNumber.isEmpty()) {
             return translate("connection.settings.emptyPortNumber");
         }
@@ -316,7 +314,7 @@ private void stop(String serverName) {
         frame.onDisconnecting();
     }
 
-    private NetworkAssistedEngineConfiguration extractConfiguration(String connectionParams) {
+    private static NetworkAssistedEngineConfiguration extractConfiguration(String connectionParams) {
         if (connectionParams != null) {
             int portStart = connectionParams.lastIndexOf('*');
             if (portStart > 0) {
@@ -395,13 +393,13 @@ private void onCompressorEngineConfigured(NetworkCompressorConfigurationMessage
      */
     private void onClipboardRequested() {
         Log.info("Clipboard transfer request received");
-        clipboardDispatcher.sendClipboard(networkEngine, frame, this);
+        ClipboardDispatcher.sendClipboard(networkEngine, frame, this);
     }
 
     private void onScreenshotRequested(){
         Log.info("Screenshot request received");
         try {
-            networkEngine.setClipboardContents(new Robot().createScreenCapture(ScreenUtilities.getSharedScreenSize()), this);
+            NetworkEngine.setClipboardContents(new Robot().createScreenCapture(ScreenUtilities.getSharedScreenSize()), this);
         } catch (AWTException e) {
             Log.error("Failed to capture screen", e);
         }
diff --git a/src/main/java/mpo/dayon/assisted/utils/ScreenUtilities.java b/src/main/java/mpo/dayon/assisted/utils/ScreenUtilities.java
index 7dc1bef5..4713091a 100644
--- a/src/main/java/mpo/dayon/assisted/utils/ScreenUtilities.java
+++ b/src/main/java/mpo/dayon/assisted/utils/ScreenUtilities.java
@@ -45,11 +45,13 @@ private ScreenUtilities() {
         }
     }
 
-    public static synchronized void setShareAllScreens(boolean doShareAllScreens) {
-        shareAllScreens = doShareAllScreens;
-        sharedScreenSize = doShareAllScreens ? COMBINED_SCREEN_SIZE : DEFAULT_SIZE;
-        rgb = new int[sharedScreenSize.height * sharedScreenSize.width];
-        gray = new byte[rgb.length];
+    public static void setShareAllScreens(boolean doShareAllScreens) {
+        synchronized (ScreenUtilities.class) {
+            shareAllScreens = doShareAllScreens;
+            sharedScreenSize = doShareAllScreens ? COMBINED_SCREEN_SIZE : DEFAULT_SIZE;
+            rgb = new int[sharedScreenSize.height * sharedScreenSize.width];
+            gray = new byte[rgb.length];
+        }
     }
 
     public static Rectangle getSharedScreenSize() {
diff --git a/src/main/java/mpo/dayon/common/babylon/Babylon.java b/src/main/java/mpo/dayon/common/babylon/Babylon.java
index a9d7896a..effb6ecd 100644
--- a/src/main/java/mpo/dayon/common/babylon/Babylon.java
+++ b/src/main/java/mpo/dayon/common/babylon/Babylon.java
@@ -16,25 +16,27 @@ public final class Babylon {
     private Babylon() {
     }
 
-    public static synchronized String translate(String tag, Object... arguments) {
-        final Locale locale = Locale.getDefault();
-        final ResourceBundle bundle = ResourceBundle.getBundle(BUNDLE, locale);
-        String value;
-        try {
-            value = bundle.getString(tag);
-            if (value.trim().isEmpty()) {
+    public static String translate(String tag, Object... arguments) {
+        synchronized (Babylon.class) {
+            final Locale locale = Locale.getDefault();
+            final ResourceBundle bundle = ResourceBundle.getBundle(BUNDLE, locale);
+            String value;
+            try {
+                value = bundle.getString(tag);
+                if (value.trim().isEmpty()) {
+                    value = tag;
+                }
+            } catch (MissingResourceException ignored) {
                 value = tag;
             }
-        } catch (MissingResourceException ignored) {
-            value = tag;
-        }
-        if (arguments != null && arguments.length > 0) {
-            value = formatValue(locale, value, tag, arguments);
-        }
-        if (value != null) {
-            return value.trim();
+            if (arguments != null && arguments.length > 0) {
+                value = formatValue(locale, value, tag, arguments);
+            }
+            if (value != null) {
+                return value.trim();
+            }
+            return null;
         }
-        return null;
     }
 
     @java.lang.SuppressWarnings("squid:S4973")
diff --git a/src/main/java/mpo/dayon/common/capture/CaptureEngineConfiguration.java b/src/main/java/mpo/dayon/common/capture/CaptureEngineConfiguration.java
index 4c52c46c..3c80c1b2 100644
--- a/src/main/java/mpo/dayon/common/capture/CaptureEngineConfiguration.java
+++ b/src/main/java/mpo/dayon/common/capture/CaptureEngineConfiguration.java
@@ -65,7 +65,7 @@ public boolean equals(Object o) {
 
         final CaptureEngineConfiguration that = (CaptureEngineConfiguration) o;
 
-        return captureTick == that.getCaptureTick() && captureQuantization == that.getCaptureQuantization() && captureColors == that.captureColors;
+        return captureTick == that.captureTick && captureQuantization == that.captureQuantization && captureColors == that.captureColors;
     }
 
     @Override
diff --git a/src/main/java/mpo/dayon/common/gui/common/BaseFrame.java b/src/main/java/mpo/dayon/common/gui/common/BaseFrame.java
index d774d7d1..02794547 100644
--- a/src/main/java/mpo/dayon/common/gui/common/BaseFrame.java
+++ b/src/main/java/mpo/dayon/common/gui/common/BaseFrame.java
@@ -146,11 +146,11 @@ private void updateInputLocale() {
         }
     }
 
-    protected JButton createButton(Action action) {
+    protected static JButton createButton(Action action) {
         return createButton(action, true);
     }
 
-    protected JButton createButton(Action action, boolean visible) {
+    protected static JButton createButton(Action action, boolean visible) {
         final JButton button = new JButton();
         addButtonProperties(action, button);
         button.setVisible(visible);
@@ -161,7 +161,7 @@ protected JToggleButton createToggleButton(Action action) {
         return createToggleButton(action, true);
     }
 
-    protected JToggleButton createToggleButton(Action action, boolean visible) {
+    protected static JToggleButton createToggleButton(Action action, boolean visible) {
         final JToggleButton button = new JToggleButton();
         addButtonProperties(action, button);
         button.setVisible(visible);
@@ -174,7 +174,7 @@ protected JToggleButton createToggleButton(Action action, boolean visible, boole
         return button;
     }
 
-    private void addButtonProperties(Action action, AbstractButton button) {
+    private static void addButtonProperties(Action action, AbstractButton button) {
         button.setMargin(ZERO_INSETS);
         button.setHideActionText(true);
         button.setAction(action);
@@ -401,7 +401,7 @@ private JPanel createPanel(JTextField addressTextField, JTextField portNumberTex
         return panel;
     }
 
-    private String toUpperFirst(String text) {
+    private static String toUpperFirst(String text) {
         return Pattern.compile("^.").matcher(text).replaceFirst(m -> m.group().toUpperCase());
     }
 
@@ -428,7 +428,7 @@ private String validateInputFields(JTextField addressTextField, JTextField portN
         return null;
     }
 
-    private void updateAssistedNetworkConfiguration(JTextField addressTextField, JTextField portNumberTextField, JCheckBox autoConnectCheckBox, String newTokenServerUrl) {
+    private static void updateAssistedNetworkConfiguration(JTextField addressTextField, JTextField portNumberTextField, JCheckBox autoConnectCheckBox, String newTokenServerUrl) {
         final NetworkAssistedEngineConfiguration newNetworkConfiguration = new NetworkAssistedEngineConfiguration(
                 addressTextField.getText().trim(), Integer.parseInt(portNumberTextField.getText()), autoConnectCheckBox.isSelected(), newTokenServerUrl);
 
@@ -437,19 +437,19 @@ private void updateAssistedNetworkConfiguration(JTextField addressTextField, JTe
         }
     }
 
-    private void updateAssistantNetworkConfiguration(JTextField portNumberTextField, String newTokenServerUrl, NetworkAssistantEngine networkEngine) {
+    private static void updateAssistantNetworkConfiguration(JTextField portNumberTextField, String newTokenServerUrl, NetworkAssistantEngine networkEngine) {
         final NetworkAssistantEngineConfiguration newNetworkConfiguration = new NetworkAssistantEngineConfiguration(
                 Integer.parseInt(portNumberTextField.getText()), newTokenServerUrl);
 
         NetworkAssistantEngineConfiguration networkConfiguration = new NetworkAssistantEngineConfiguration();
         if (!newNetworkConfiguration.equals(networkConfiguration)) {
-            networkEngine.manageRouterPorts(networkConfiguration.getPort(), newNetworkConfiguration.getPort());
+            NetworkAssistantEngine.manageRouterPorts(networkConfiguration.getPort(), newNetworkConfiguration.getPort());
             newNetworkConfiguration.persist();
             networkEngine.reconfigure(newNetworkConfiguration);
         }
     }
 
-    private void updateSystemProperty(String newTokenServerUrl) {
+    private static void updateSystemProperty(String newTokenServerUrl) {
         if (newTokenServerUrl.isEmpty()) {
             System.clearProperty("dayon.custom.tokenServer");
             return;
@@ -457,7 +457,7 @@ private void updateSystemProperty(String newTokenServerUrl) {
         System.setProperty("dayon.custom.tokenServer", newTokenServerUrl);
     }
 
-    private GridBagConstraints createGridBagConstraints(int gridy) {
+    private static GridBagConstraints createGridBagConstraints(int gridy) {
         GridBagConstraints gc = new GridBagConstraints();
         gc.fill = HORIZONTAL;
         gc.gridx = 0;
@@ -465,7 +465,7 @@ private GridBagConstraints createGridBagConstraints(int gridy) {
         return gc;
     }
 
-    private boolean isActiveTokenServer(String tokenServer) {
+    private static boolean isActiveTokenServer(String tokenServer) {
         CompletableFuture<Boolean> future = CompletableFuture.supplyAsync(() -> {
             try {
                 // HttpClient doesn't implement AutoCloseable nor close before Java 21!
@@ -575,7 +575,7 @@ protected static JLabel getFingerprints() {
         return fingerprints;
     }
 
-    protected void clearFingerprints() {
+    protected static void clearFingerprints() {
         fingerprints.setText(null);
         fingerprints.setIcon(null);
         fingerprints.setCursor(null);
diff --git a/src/main/java/mpo/dayon/common/gui/statusbar/StatusBar.java b/src/main/java/mpo/dayon/common/gui/statusbar/StatusBar.java
index 7b48f443..983f7a4f 100644
--- a/src/main/java/mpo/dayon/common/gui/statusbar/StatusBar.java
+++ b/src/main/java/mpo/dayon/common/gui/statusbar/StatusBar.java
@@ -14,7 +14,7 @@
 import static mpo.dayon.common.babylon.Babylon.translate;
 
 public class StatusBar extends JPanel {
-    
+
     private static final int HEIGHT = 5;
     private final JLabel message = new JLabel();
     private final JLabel sessionDuration = new JLabel("00:00:00");
@@ -30,7 +30,7 @@ public StatusBar() {
     }
 
     public void clearMessage() {
-        this.message.setText(null);
+        message.setText(null);
     }
 
     public void setMessage(String message) {
@@ -51,48 +51,39 @@ public String getKeyboardLayout() {
     }
 
     private void addKeyboardLayout() {
-        final Dimension dimension = new Dimension(60, HEIGHT);
-        keyboardLayout.setHorizontalAlignment(CENTER);
-        keyboardLayout.setSize(dimension);
-        keyboardLayout.setPreferredSize(dimension);
         add(keyboardLayout);
     }
 
     public <T> void addCounter(Counter<T> counter, int width) {
-        final JLabel lbl = new JLabel(counter.getUid());
-        final Dimension dimension = new Dimension(width, HEIGHT);
-        lbl.setHorizontalAlignment(CENTER);
-        lbl.setSize(dimension);
-        lbl.setPreferredSize(dimension);
-        lbl.setToolTipText(counter.getShortDescription());
-        counter.addListener((counter1, value) -> lbl.setText(counter1.formatInstantValue(value)));
-        add(lbl);
+        JLabel label = createLabel(counter.getUid(), width);
+        label.setToolTipText(counter.getShortDescription());
+        counter.addListener((counter1, value) -> label.setText(counter1.formatInstantValue(value)));
+        add(label);
     }
 
     public void addRamInfo() {
-        final JLabel lbl = new JLabel();
-        final Dimension dimension = new Dimension(110, HEIGHT);
-        lbl.setHorizontalAlignment(CENTER);
-        lbl.setSize(dimension);
-        lbl.setPreferredSize(dimension);
-        BigBrother.get().registerRamInfo(new MemoryCounter(lbl));
-        lbl.setToolTipText(translate("memory.info"));
-        add(lbl);
+        JLabel label = createLabel("", 110);
+        BigBrother.get().registerRamInfo(new MemoryCounter(label));
+        label.setToolTipText(translate("memory.info"));
+        add(label);
     }
 
     public void addConnectionDuration() {
-        final Dimension dimension = new Dimension(65, HEIGHT);
         sessionDuration.setHorizontalAlignment(RIGHT);
-        sessionDuration.setSize(dimension);
-        sessionDuration.setPreferredSize(dimension);
+        sessionDuration.setPreferredSize(new Dimension(65, HEIGHT));
         sessionDuration.setToolTipText(translate("session.duration"));
         add(sessionDuration);
     }
 
     public void addSeparator() {
-        final JToolBar.Separator separator = new JToolBar.Separator();
-        separator.setOrientation(VERTICAL);
-        add(separator);
+        add(new JToolBar.Separator(new Dimension(5, HEIGHT)));
+    }
+
+    private JLabel createLabel(String text, int width) {
+        JLabel label = new JLabel(text);
+        label.setHorizontalAlignment(CENTER);
+        label.setPreferredSize(new Dimension(width, HEIGHT));
+        return label;
     }
 
     private static class MemoryCounter extends TimerTask {
diff --git a/src/main/java/mpo/dayon/common/log/file/FileAppender.java b/src/main/java/mpo/dayon/common/log/file/FileAppender.java
index 4ffb9fe5..3d5a54f8 100644
--- a/src/main/java/mpo/dayon/common/log/file/FileAppender.java
+++ b/src/main/java/mpo/dayon/common/log/file/FileAppender.java
@@ -35,27 +35,29 @@ public FileAppender(String filename) throws FileNotFoundException {
 		setupFile(filename, true);
 	}
 
-	@Override
-    public synchronized void append(LogLevel level, String message, Throwable error) {
-		try {
-			StringBuilder builder = new StringBuilder();
-			builder.append(format(level, message)).append(System.lineSeparator());
-			if (error != null) {
-				builder.append(getStackTrace(error)).append(System.lineSeparator());
-			}
-			count += builder.length();
-			if (count >= MAX_FILE_SIZE && count >= nextRolloverCount) {
-				rollOver();
-			}
-			writer.write(builder.toString());
-			writer.flush();
-		} catch (RuntimeException ex) {
-			fallback.append(level, message, error);
-			fallback.append(LogLevel.WARN, "[FileAppender] error", ex);
-		}
-	}
-
-	private String getStackTrace(Throwable error) {
+    @Override
+    public void append(LogLevel level, String message, Throwable error) {
+        synchronized (this) {
+            try {
+                StringBuilder builder = new StringBuilder(64);
+                builder.append(format(level, message)).append(System.lineSeparator());
+                if (error != null) {
+                    builder.append(getStackTrace(error)).append(System.lineSeparator());
+                }
+                count += builder.length();
+                if (count >= MAX_FILE_SIZE && count >= nextRolloverCount) {
+                    rollOver();
+                }
+                writer.write(builder.toString());
+                writer.flush();
+            } catch (RuntimeException ex) {
+                fallback.append(level, message, error);
+                fallback.append(LogLevel.WARN, "[FileAppender] error", ex);
+            }
+        }
+    }
+
+	private static String getStackTrace(Throwable error) {
 		final StringWriter out = new StringWriter();
 		final PrintWriter printer = new PrintWriter(out);
 		error.printStackTrace(printer);
@@ -67,7 +69,7 @@ private void setupFile(String filename, boolean append) throws FileNotFoundExcep
 		final File file = new File(filename);
 		count = file.length();
 	}
-	
+
 	@java.lang.SuppressWarnings("squid:S106")
 	private void rollOver() {
 		nextRolloverCount = count + MAX_FILE_SIZE;
diff --git a/src/main/java/mpo/dayon/common/monitoring/BigBrother.java b/src/main/java/mpo/dayon/common/monitoring/BigBrother.java
index 98429396..7e9a5314 100644
--- a/src/main/java/mpo/dayon/common/monitoring/BigBrother.java
+++ b/src/main/java/mpo/dayon/common/monitoring/BigBrother.java
@@ -27,7 +27,7 @@ public void registerCounter(final Counter<?> counter, final long instantRatePeri
     }
 
     public void registerRamInfo(Runnable callback) {
-        scheduler.scheduleAtFixedRate(callback, 0, 1, TimeUnit.SECONDS);
+        scheduler.scheduleAtFixedRate(callback, 0, 1291, TimeUnit.MILLISECONDS);
     }
 
     public void shutdown() {
diff --git a/src/main/java/mpo/dayon/common/monitoring/counter/AverageValueCounter.java b/src/main/java/mpo/dayon/common/monitoring/counter/AverageValueCounter.java
index 892decb6..f5423c55 100644
--- a/src/main/java/mpo/dayon/common/monitoring/counter/AverageValueCounter.java
+++ b/src/main/java/mpo/dayon/common/monitoring/counter/AverageValueCounter.java
@@ -13,14 +13,12 @@ public void add(double value) {
 		add(1.0, value);
 	}
 
-	public void add(double weight, double value) {
-		synchronized (this) {
-			final double xvalue = weight * value;
+	public synchronized void add(double weight, double value) {
+        final double xvalue = weight * value;
 
-			instantWeight += weight;
-			instantValue += xvalue;
-		}
-	}
+        instantWeight += weight;
+        instantValue += xvalue;
+    }
 
 	@Override
     public void computeAndResetInstantValue() {
diff --git a/src/main/java/mpo/dayon/common/monitoring/counter/RateCounter.java b/src/main/java/mpo/dayon/common/monitoring/counter/RateCounter.java
index cf5c1abd..79cc6f5c 100644
--- a/src/main/java/mpo/dayon/common/monitoring/counter/RateCounter.java
+++ b/src/main/java/mpo/dayon/common/monitoring/counter/RateCounter.java
@@ -15,11 +15,9 @@ public String formatInstantValue(Double value) {
 
 	protected abstract String formatRate(Double rate);
 
-	public void add(double value) {
-		synchronized (this) {
-			instantValue += value;
-		}
-	}
+	public synchronized void add(double value) {
+        instantValue += value;
+    }
 
 	@Override
     public void computeAndResetInstantValue() {
diff --git a/src/main/java/mpo/dayon/common/network/ClipboardDispatcher.java b/src/main/java/mpo/dayon/common/network/ClipboardDispatcher.java
index d8890f77..d3201962 100644
--- a/src/main/java/mpo/dayon/common/network/ClipboardDispatcher.java
+++ b/src/main/java/mpo/dayon/common/network/ClipboardDispatcher.java
@@ -15,7 +15,10 @@
 
 public class ClipboardDispatcher {
 
-    public void sendClipboard(NetworkEngine networkEngine, BaseFrame frame, ClipboardOwner owner) {
+    private ClipboardDispatcher() {
+    }
+
+    public static void sendClipboard(NetworkEngine networkEngine, BaseFrame frame, ClipboardOwner owner) {
 
         Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
         Transferable content = clipboard.getContents(owner);
diff --git a/src/main/java/mpo/dayon/common/network/NetworkEngine.java b/src/main/java/mpo/dayon/common/network/NetworkEngine.java
index 324fde50..857c4499 100644
--- a/src/main/java/mpo/dayon/common/network/NetworkEngine.java
+++ b/src/main/java/mpo/dayon/common/network/NetworkEngine.java
@@ -80,23 +80,23 @@ public void sendClipboardFiles(List<File> files, long size, String basePath) {
         }
     }
 
-    protected void setClipboardContents(String string, ClipboardOwner clipboardOwner) {
+    protected static void setClipboardContents(String string, ClipboardOwner clipboardOwner) {
         Log.debug(CLIPBOARD_DEBUG, () -> string);
         StringSelection stringSelection = new StringSelection(string);
         Toolkit.getDefaultToolkit().getSystemClipboard().setContents(stringSelection, clipboardOwner);
     }
 
-    public void setClipboardContents(BufferedImage image, ClipboardOwner clipboardOwner) {
+    public static void setClipboardContents(BufferedImage image, ClipboardOwner clipboardOwner) {
         Log.debug(CLIPBOARD_DEBUG, () -> format("%dx%d", image.getWidth(), image.getHeight()));
         Toolkit.getDefaultToolkit().getSystemClipboard().setContents(new TransferableImage(image), clipboardOwner);
     }
 
-    private void setClipboardContents(List<File> files, ClipboardOwner clipboardOwner) {
+    private static void setClipboardContents(List<File> files, ClipboardOwner clipboardOwner) {
         Log.debug(CLIPBOARD_DEBUG, () -> String.valueOf(files));
         Toolkit.getDefaultToolkit().getSystemClipboard().setContents(new TransferableFiles(files), clipboardOwner);
     }
 
-    private NetworkClipboardFilesHelper handleNetworkClipboardFilesHelper(NetworkClipboardFilesHelper filesHelper, ClipboardOwner clipboardOwner) {
+    private static NetworkClipboardFilesHelper handleNetworkClipboardFilesHelper(NetworkClipboardFilesHelper filesHelper, ClipboardOwner clipboardOwner) {
         if (filesHelper.isDone()) {
             setClipboardContents(filesHelper.getFiles(), clipboardOwner);
             return new NetworkClipboardFilesHelper();
diff --git a/src/main/java/mpo/dayon/common/network/message/NetworkMessage.java b/src/main/java/mpo/dayon/common/network/message/NetworkMessage.java
index 966223f2..075d24ef 100644
--- a/src/main/java/mpo/dayon/common/network/message/NetworkMessage.java
+++ b/src/main/java/mpo/dayon/common/network/message/NetworkMessage.java
@@ -6,42 +6,34 @@
 public abstract class NetworkMessage {
     private static final byte MAGIC_NUMBER = (byte) 170;
 
-    NetworkMessage() {
-    }
+    protected NetworkMessage() {}
 
     public abstract NetworkMessageType getType();
-
-    /**
-     * Take into account some extra-info sent over the network with the actual
-     * payload ...
-     */
     public abstract int getWireSize();
-
     public abstract void marshall(ObjectOutputStream out) throws IOException;
 
     public static void marshallMagicNumber(ObjectOutputStream out) throws IOException {
-        out.writeByte(NetworkMessage.MAGIC_NUMBER);
+        out.writeByte(MAGIC_NUMBER);
     }
 
     public static void unmarshallMagicNumber(ObjectInputStream in) throws IOException {
-        if (NetworkMessage.MAGIC_NUMBER != in.readByte()) {
+        if (MAGIC_NUMBER != in.readByte()) {
             throw new IOException("Protocol error!");
         }
     }
 
-    static <T extends Enum<T>> void marshallEnum(ObjectOutputStream out, Enum<T> value) throws IOException {
+    public static <T extends Enum<T>> void marshallEnum(ObjectOutputStream out, Enum<T> value) throws IOException {
         out.write(value.ordinal());
     }
 
     public static <T extends Enum<T>> T unmarshallEnum(ObjectInputStream in, Class<T> enumClass) throws IOException {
-        final byte ordinal = in.readByte();
-        final T[] xenums = enumClass.getEnumConstants();
-        return Arrays.stream(xenums)
-                .filter(xenum -> xenum.ordinal() == ordinal)
+        byte ordinal = in.readByte();
+        return Arrays.stream(enumClass.getEnumConstants())
+                .filter(x -> x.ordinal() == ordinal)
                 .findFirst()
-                .orElseThrow(() -> new IllegalArgumentException("Unknown " + enumClass.getSimpleName() + " [" + ordinal + "] enum!"));
+                .orElseThrow(() -> new IllegalArgumentException("Unknown " + enumClass.getSimpleName() + " enum!"));
     }
 
     @Override
     public abstract String toString();
-}
+}
\ No newline at end of file
diff --git a/src/main/java/mpo/dayon/common/security/CustomTrustManager.java b/src/main/java/mpo/dayon/common/security/CustomTrustManager.java
index eccffa37..c6ef8ee5 100644
--- a/src/main/java/mpo/dayon/common/security/CustomTrustManager.java
+++ b/src/main/java/mpo/dayon/common/security/CustomTrustManager.java
@@ -19,9 +19,11 @@
 import static java.lang.System.getProperty;
 
 public class CustomTrustManager implements X509TrustManager {
+	private static final X509Certificate[] ACCEPTED = {};
+
 	@Override
 	public X509Certificate[] getAcceptedIssuers() {
-		return new X509Certificate[]{};
+		return ACCEPTED;
 	}
 
 	@Override
diff --git a/src/main/java/mpo/dayon/common/squeeze/RegularRunLengthEncoder.java b/src/main/java/mpo/dayon/common/squeeze/RegularRunLengthEncoder.java
index 6bfcc1cd..25736e08 100644
--- a/src/main/java/mpo/dayon/common/squeeze/RegularRunLengthEncoder.java
+++ b/src/main/java/mpo/dayon/common/squeeze/RegularRunLengthEncoder.java
@@ -39,7 +39,7 @@ public void runLengthEncode(MemByteBuffer out, MemByteBuffer capture) {
         }
     }
 
-    private void writeNonZero(MemByteBuffer out, int count) {
+    private static void writeNonZero(MemByteBuffer out, int count) {
         if (count > 0) {
             out.write(count);
         }
diff --git a/src/main/java/mpo/dayon/common/squeeze/RegularTileCache.java b/src/main/java/mpo/dayon/common/squeeze/RegularTileCache.java
index 99553d6f..9bce821a 100644
--- a/src/main/java/mpo/dayon/common/squeeze/RegularTileCache.java
+++ b/src/main/java/mpo/dayon/common/squeeze/RegularTileCache.java
@@ -14,24 +14,19 @@ public class RegularTileCache implements TileCache {
     private final Map<Integer, CaptureTile> tiles;
     private final int maxSize;
     private final int purgeSize;
-    private int hits;
+    private int hits = 0;
 
     public RegularTileCache(int maxSize, int purgeSize) {
         this.maxSize = maxSize;
         this.purgeSize = purgeSize;
         tiles = new LinkedHashMap<>(maxSize, 0.75f, true) {
-            @Override
-            protected boolean removeEldestEntry(Map.Entry<Integer, CaptureTile> eldest) {
-                return size() > maxSize;
-            }
-
             @Override
             public CaptureTile get(Object key) {
                 CaptureTile tile = super.get(key);
                 if (tile != null) {
                     ++hits;
                 }
-                return tile;
+                return tile != null ? tile : CaptureTile.MISSING;
             }
         };
         Log.info("Regular cache created [MAX:" + maxSize + "][PURGE:" + purgeSize + "]");
@@ -53,8 +48,7 @@ public void add(CaptureTile tile) {
 
     @Override
     public CaptureTile get(int cacheId) {
-        CaptureTile tile = tiles.get(cacheId);
-        return tile != null ? tile : CaptureTile.MISSING;
+        return tiles.get(cacheId);
     }
 
     @Override
diff --git a/src/main/java/mpo/dayon/common/utils/SystemUtilities.java b/src/main/java/mpo/dayon/common/utils/SystemUtilities.java
index e1765b38..ede8be9a 100644
--- a/src/main/java/mpo/dayon/common/utils/SystemUtilities.java
+++ b/src/main/java/mpo/dayon/common/utils/SystemUtilities.java
@@ -15,6 +15,7 @@
 import java.security.NoSuchAlgorithmException;
 import java.time.Duration;
 import java.util.*;
+import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -28,6 +29,8 @@ public final class SystemUtilities {
     public static final String FLATPAK_BROWSER = "/app/bin/dayon.browser";
     private static final String JAVA_VENDOR = "java.vendor";
     public static final String DEFAULT_TOKEN_SERVER_URL = "https://fensterkitt.ch/dayon/";
+    private static final Pattern FQ_HOSTNAME_REGEX = Pattern.compile("^([a-zA-Z\\d][a-zA-Z\\d\\-]{0,61}[a-zA-Z\\d]\\.)*[a-zA-Z]{2,}$");
+    private static final Pattern IPV4_REGEX = Pattern.compile("(\\d{1,3})");
 
     private SystemUtilities() {
     }
@@ -69,7 +72,7 @@ private static void cleanDir(File folder) throws IOException {
     }
 
     public static List<String> getSystemProperties() {
-        final List<String> props = new ArrayList<>();
+        final List<String> props = new ArrayList<>(64);
         final List<String> propNames = System.getProperties().keySet().stream().map(Object::toString).collect(Collectors.toList());
         final int size = propNames.stream().max(Comparator.comparing(String::length)).orElse("").length();
         final String format = "%" + size + "." + size + "s [%s]";
@@ -78,7 +81,7 @@ public static List<String> getSystemProperties() {
             String propValue = getProperty(propName);
             // I want to display the actual content of the line separator...
             if (propName.equals("line.separator")) {
-                StringBuilder hex = new StringBuilder();
+                StringBuilder hex = new StringBuilder(3);
                 for (int idx = 0; idx < propValue.length(); idx++) {
                     final int cc = propValue.charAt(idx);
                     hex.append("\\").append(cc);
@@ -188,15 +191,15 @@ private static boolean isValidIpV6(String serverName) {
     @java.lang.SuppressWarnings("squid:S5998") // matcher input is max 256 chars long
     private static boolean isValidHostname(String serverName) {
         return !isLookingLikeAnIpV4(serverName) && serverName.length() < 256 &&
-                serverName.matches("^([a-zA-Z\\d][a-zA-Z\\d\\-]{0,61}[a-zA-Z\\d]\\.)*[a-zA-Z]{2,}$");
+                FQ_HOSTNAME_REGEX.matcher(serverName).matches();
     }
 
     public static boolean isValidUrl(String url) {
         try {
             new URI(url);
             if (url.startsWith("http://") || url.startsWith("https://")) {
-                if (url.lastIndexOf("/") > 7) {
-                    return isValidIpAddressOrHostName(url.substring(url.indexOf("://") + 3, url.indexOf("/", url.indexOf("://") + 3)));
+                if (url.lastIndexOf('/') > 7) {
+                    return isValidIpAddressOrHostName(url.substring(url.indexOf("://") + 3, url.indexOf('/', url.indexOf("://") + 3)));
                 } else {
                     return isValidIpAddressOrHostName(url.substring(url.indexOf("://") + 3));
                 }
@@ -208,7 +211,7 @@ public static boolean isValidUrl(String url) {
     }
 
     private static boolean isLookingLikeAnIpV4(String serverName) {
-        return Arrays.stream(serverName.split("\\.")).allMatch(e -> e.matches("(\\d{1,3})"));
+        return Arrays.stream(serverName.split("\\.")).allMatch(e -> IPV4_REGEX.matcher(e).matches());
     }
 
     public static boolean isValidToken(String token) throws NoSuchAlgorithmException {
diff --git a/src/main/java/mpo/dayon/common/version/Version.java b/src/main/java/mpo/dayon/common/version/Version.java
index e34e7dec..d5ce79dc 100644
--- a/src/main/java/mpo/dayon/common/version/Version.java
+++ b/src/main/java/mpo/dayon/common/version/Version.java
@@ -87,13 +87,13 @@ public String getLatestRelease() {
     }
 
     public static boolean isCompatibleVersion(int major, int minor, Version that) {
-        if (!isProd(major, minor) || !isProd(that.getMajor(), that.getMajor())) {
+        if (!isProd(major, minor) || !isProd(that.major, that.major)) {
             return true;
         }
-        if (that.getMajor() > 10 && (major > 10 || (major == 1 && minor == 10))) {
+        if (that.major > 10 && (major > 10 || (major == 1 && minor == 10))) {
             return true;
         }
-        return that.getMajor() == major && that.getMinor() == minor;
+        return that.major == major && that.minor == minor;
     }
 
     public static boolean isOutdatedVersion(int major, int otherMajor) {