write common classes

common/src/main/java/common/LoggerUtil.java

+package common;
+
+import java.io.BufferedWriter;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+
+public class LoggerUtil {
+    private static final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
+
+    // Memory queue to hold log messages
+    private static final BlockingQueue<String> logQueue = new LinkedBlockingQueue<>();
+    private static BufferedWriter writer;
+
+    static {
+        try {
+            // Keep the file open for better performance
+            writer = new BufferedWriter(new FileWriter(ZkConfig.CLUSTER_LOG_FILE, true));
+
+            // Start a background thread to process logs asynchronously
+            Thread logThread = new Thread(() -> {
+                try {
+                    while (true) {
+                        String message = logQueue.take(); // Wait for a message in the queue
+                        writer.write(message);
+                        writer.newLine();
+                        writer.flush(); // Flush to disk without closing
+                    }
+                } catch (InterruptedException | IOException e) {
+                    Thread.currentThread().interrupt();
+                }
+            });
+
+            logThread.setDaemon(true); // Let it close when the main application stops
+            logThread.start();
+
+        } catch (IOException e) {
+            System.err.println("Failed to initialize fast logger: " + e.getMessage());
+        }
+    }
+
+    /**
+     * Rapidly logs an event by adding it to an internal queue.
+     * This method is non-blocking and returns almost instantly.
+     */
+    public static void log(String message) {
+        String timestampedMessage = String.format("[%s] %s", LocalDateTime.now().format(formatter), message);
+
+        // Print to console (fast)
+        System.out.println(timestampedMessage);
+
+        // Offer the message to the background logging thread
+        logQueue.offer(timestampedMessage);
+    }
+}
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common/src/main/java/common/ZkConfig.java

+package common;
+
+public class ZkConfig {
+    public static final String ZOOKEEPER_ADDRESS = "192.168.98.208:2181";
+    public static final int SESSION_TIMEOUT = 5000;
+
+    // Root paths for the cluster components
+    public static final String NODES_PARENT_PATH = "/nodes";
+    public static final String WORKERS_PARENT_PATH = "/workers";
+    public static final String TASKS_PARENT_PATH = "/tasks";
+
+    // Shared log file path
+    public static final String CLUSTER_LOG_FILE = "cluster_events.log";
+}
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