Update onElectedToBeLeader function to register as coordinator and store it's IP address

registration-discovery-leader-reelection-cordinator-workers/src/main/java/Registration_Discovery/ServiceRegistry.java

@@ -14,8 +14,8 @@ public class ServiceRegistry implements Watcher {
     private static final Logger logger = LoggerFactory.getLogger(ServiceRegistry.class);
 
     private static final String REGISTRY_ZNODE = "/service_registry";
+    private static final String COORDINATOR_ZNODE = "/cordinator";
     private final ZooKeeper zooKeeper;
-
     private String currentZnode = null;
     private static List<String> allServiceAddresses = null;
 
@@ -26,6 +26,7 @@ public class ServiceRegistry implements Watcher {
     public ServiceRegistry(ZooKeeper zooKeeper) {
         this.zooKeeper = zooKeeper;
         createServiceRegistryZnode();
+        createCoordinatorZnode();
     }
 
     private void createServiceRegistryZnode() {
@@ -39,6 +40,17 @@ public class ServiceRegistry implements Watcher {
             e.printStackTrace();
         }
     }
+    private void createCoordinatorZnode() {
+        try {
+            if (zooKeeper.exists(COORDINATOR_ZNODE, false) == null) {
+                zooKeeper.create(COORDINATOR_ZNODE, new byte[]{}, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
+            }
+        } catch (KeeperException e) {
+            e.printStackTrace();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
 
     public void registerToCluster(String metadata) throws KeeperException, InterruptedException {
         if (this.currentZnode != null) {
@@ -51,6 +63,12 @@ public class ServiceRegistry implements Watcher {
 //        System.out.println("Registered to service registry");
         logger.debug("Registered to service registry");
     }
+    public void registerToClusterAsCoordinator(String metadata) throws KeeperException, InterruptedException {
+
+        zooKeeper.create(COORDINATOR_ZNODE + "/C_", metadata.getBytes(),
+                ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
+        logger.debug("Register to cluster as coordinator");
+    }
 
     public void registerForUpdates() {
         try {
@@ -62,6 +80,7 @@ public class ServiceRegistry implements Watcher {
         }
     }
 
+
     public void unregisterFromCluster() {
         try {
             if (currentZnode != null && zooKeeper.exists(currentZnode, false) != null) {