Fourth Commit : Wroking Fine All but NO SSH and No Logging - Dublicating...

Fourth Commit : Wroking Fine All but NO SSH and No Logging - Dublicating Physical Nodes Solved and Transient Workers are Steady and Stable

src/main/java/Application.java

@@ -27,7 +27,6 @@ public class Application implements Watcher {
 
         int currentServerPort = args.length == 3 ? Integer.parseInt(args[0]) : DEFAULT_PORT;
         numberOfInstances = args.length == 3 ? Integer.parseInt(args[1]) : 4;
-
         pathToFile = args.length == 3 ? args[2] : "TransientWorker_jar/Registration&Discovery-AutoHealer.jar";
         pathToFile = System.getProperty("user.dir") + RELATIVE_PATH_TO_JARS + pathToFile;
 
@@ -39,7 +38,7 @@ public class Application implements Watcher {
         OnElectionAction onElectionAction = new OnElectionAction(serviceRegistry, currentServerPort);
 
         LeaderElection leaderElection = new LeaderElection(zooKeeper, onElectionAction);
-        String ss = leaderElection.volunteerForLeadership();
+        leaderElection.volunteerForLeadership();
         leaderElection.reelectLeader();
 
         application.run();

src/main/java/LeaderElection.java

@@ -23,7 +23,7 @@ public class LeaderElection implements Watcher {
 
     public void volunteerForLeadership() throws InterruptedException, KeeperException, UnknownHostException {
 
-        String znodePrefix = ELECTION_NAMESPACE + "/node_";
+        String znodePrefix = ELECTION_NAMESPACE + "/c_";
         String IP = InetAddress.getLocalHost().getHostAddress();
         String username = System.getProperty("user.name")+"@"+IP;
         String znodeFullPath = zooKeeper.create(znodePrefix, username.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
@@ -45,6 +45,7 @@ public class LeaderElection implements Watcher {
             String smallestChild = children.get(0); //the first element
             if (smallestChild.equals(currentZnodeName)) {
                 System.out.println("I'm a leader");
+
                 onElectionCallback.onElectedToBeLeader();
                 return;
             }

src/main/java/NodeSorting.java

@@ -12,13 +12,22 @@ public class NodeSorting
             this.node = x;
             this.tasksNo = y;
         }
+        @Override
+        public String toString()
+        {
+            return "node : " + this.node +" has : " + tasksNo + " workers !!";
+        }
     }
     public static List<String> sort(List<byte[]> workers , List<String> Nodes)
     {
         Map<String , Integer> map = new HashMap<>();
+        System.out.println("physical nodes are : " + Nodes);
+        System.out.println("jars running are : " + workers.size());
+
         for (byte[] worker : workers)
         {
             String s = new String(worker);
+            if (!Nodes.contains(s)) continue;
             int x = map.getOrDefault(s , 0);
             map.put(s , x+1);
         }
@@ -43,7 +52,7 @@ public class NodeSorting
         };
         List<String> ans = new ArrayList<>();
         Collections.sort(temp, comparator);
-
+        System.out.println(temp);
         for (Pair pair : temp)
         {
             ans.add(pair.node);

src/main/java/ServiceRegistry.java

@@ -49,7 +49,7 @@ public class ServiceRegistry implements Watcher
             System.out.println("Already registered to service registry");
             return;
         }
-        this.currentZnode = zooKeeper.create(PHYSICAL_ZNODES_PATH + "/node_", metadata.getBytes(),
+        this.currentZnode = zooKeeper.create(PHYSICAL_ZNODES_PATH + "/physical_node_", metadata.getBytes(),
                 ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
         System.out.println("Registered to service registry");
     }
@@ -78,14 +78,14 @@ public class ServiceRegistry implements Watcher
         }
     }
 
-    private void masterJob() throws InterruptedException, KeeperException, IOException {
+    private synchronized void masterJob() throws InterruptedException, KeeperException, IOException {
         updateAddresses();
         launchWorkersIfNecessary();
     }
 
-    private synchronized void updateAddresses() throws KeeperException, InterruptedException
+    private void updateAddresses() throws KeeperException, InterruptedException
     {
-        List<String> workerZnodes = zooKeeper.getChildren(PHYSICAL_ZNODES_PATH, this);
+        List<String> workerZnodes = zooKeeper.getChildren(PHYSICAL_ZNODES_PATH, false);
 
         List<String> addresses = new ArrayList<>(workerZnodes.size());
 
@@ -105,57 +105,66 @@ public class ServiceRegistry implements Watcher
         System.out.println("The cluster addresses are: " + this.allServiceAddresses);
     }
 
-    private void launchWorkersIfNecessary() throws KeeperException, InterruptedException, IOException {
-        synchronized (zooKeeper)
+    private void launchWorkersIfNecessary() throws KeeperException, InterruptedException, IOException
+    {
+        List<String> physicalZnodes = zooKeeper.getChildren(PHYSICAL_ZNODES_PATH, this);
+
+        List<String> workers = zooKeeper.getChildren(WORKERS_ZNODES_PATH, this);
+
+        //System.out.println("Total workers (before editing) = " + workers.size());
+
+        for (String worker : workers)
         {
-            List<String> physicalZnodes = zooKeeper.getChildren(PHYSICAL_ZNODES_PATH, false);
-            List<String> workers = zooKeeper.getChildren(WORKERS_ZNODES_PATH, this);
-            for (String worker : workers) {
-                Stat stat = zooKeeper.exists(WORKERS_ZNODES_PATH + "/" + worker, false);
-                if (stat == null) {
-                    workers.remove(worker);
-                    continue;
-                }
+            Stat stat = zooKeeper.exists(WORKERS_ZNODES_PATH + "/" + worker, false);
+            if (stat == null) {
+                workers.remove(worker);
+                continue;
+            }
 
-                String node = new String(zooKeeper.getData(WORKERS_ZNODES_PATH + "/" + worker, false, stat));
-                if (physicalZnodes.contains(node)) {
-                    System.out.println("NODE ALREADY EXIST");
-                    continue;
-                }
+            String node = new String(zooKeeper.getData(WORKERS_ZNODES_PATH + "/" + worker, false, stat));
+            if (!physicalZnodes.contains(node))
+            {
+                //System.out.println("Physical Node is shut down !!");
                 workers.remove(worker);
             }
+        }
 
-            int neededInstances = numberOfInstances - workers.size();
+        List<String> sortedWorkers = NodeSorting.sort(getOriginalNodes(workers), physicalZnodes);
 
-            System.out.println("Needed Instances is : " + neededInstances);
+        while (workers.size() > numberOfInstances)
+        {
+            Stat stat = zooKeeper.exists(WORKERS_ZNODES_PATH + "/" + workers.get(0), false);
+            if (stat == null) {
+                workers.remove(0);
+                continue;
+            }
+            zooKeeper.delete(WORKERS_ZNODES_PATH + "/" + workers.get(0) , -1);
+        }
 
-            int index = 0;
+        int neededInstances = numberOfInstances - workers.size();
 
-            int code = 1;
+        if (neededInstances <= 0) return;
 
+        System.out.println("Needed Instances is : " + neededInstances);
 
-            List<String> sortedWorkers = NodeSorting.sort(getOriginalNodes(workers), physicalZnodes);
+        int index = 0;
 
-            while (neededInstances > 0 && sortedWorkers.size() > 0)
+        int size = sortedWorkers.size();
+        while (neededInstances>0
+                && size>0)
+        {
+            Stat stat = zooKeeper.exists(PHYSICAL_ZNODES_PATH + "/" + sortedWorkers.get(index), false);
+            if (stat == null)
             {
-                Stat stat = zooKeeper.exists(PHYSICAL_ZNODES_PATH + "/" + sortedWorkers.get(index), false);
-                if (stat == null) {
-                    code++;
-                    if (code > sortedWorkers.size()) {
-                        break;
-                    }
-                    continue;
-                }
-
-                System.out.println("I am In the While !!" + " Turn for " + sortedWorkers.get(index));
-                startNewWorker(sortedWorkers.get(index));
-
-                neededInstances--;
-
-                index = (index + 1) % sortedWorkers.size();
+                sortedWorkers.remove(index);
+                size--;
+                continue;
             }
-
+            startNewWorker(sortedWorkers.get(index));
+            neededInstances--;
+            index = (index + 1) % size;
         }
+
     }
 
     private List<byte[]> getOriginalNodes(List<String> workers) throws InterruptedException, KeeperException {
@@ -165,6 +174,8 @@ public class ServiceRegistry implements Watcher
             Stat stat = zooKeeper.exists(WORKERS_ZNODES_PATH+"/"+worker ,false);
             if (stat == null) continue;
             ans.add(zooKeeper.getData(WORKERS_ZNODES_PATH+"/"+worker,false,stat ));
+           // String jj = new String(ans.get(ans.size()-1));
+           // System.out.println("worker : " +worker + " belongs to : " + jj);
         }
         return ans;
     }
@@ -200,10 +211,19 @@ public class ServiceRegistry implements Watcher
     @Override
     public void process(WatchedEvent watchedEvent)
     {
-        try {
-            masterJob();
-        } catch (InterruptedException | KeeperException | IOException e) {
-            throw new RuntimeException(e);
+        switch (watchedEvent.getType())
+        {
+            case NodeChildrenChanged:
+            {
+                try
+                {
+                    masterJob();
+                }
+                catch (InterruptedException | KeeperException | IOException e) {
+                    throw new RuntimeException(e);
+                }
+            }
+
         }
     }
 

src/main/java/TestLogging.java

@@ -3,6 +3,7 @@ import ch.qos.logback.core.FileAppender;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.File;
 import java.io.IOException;
 
 public class TestLogging {
@@ -25,9 +26,14 @@ public class TestLogging {
     }
 
     public static void main(String[] args) throws InterruptedException, IOException {
-/*
+
          String remoteDirectory = "/JavaJars/";
 
+        String RELATIVE_PATH_TO_JARS = "/out/artifacts/";
+        String pathToFile = args.length == 3 ? args[2] : "TransientWorker_jar/Registration&Discovery-AutoHealer.jar";
+        pathToFile = System.getProperty("user.dir") + RELATIVE_PATH_TO_JARS + pathToFile;
+        File file = new File(pathToFile);
+        String remoteUser = "root@192.168.184.10";
          String pathToProgram  = System.getProperty("user.dir") + RELATIVE_PATH_TO_JARS + pathToFile;
          String remoteJarFilePath = remoteDirectory + file.getName();
 
@@ -41,6 +47,6 @@ public class TestLogging {
          scpProcess.waitFor();
          if (scpProcess.exitValue() == 0) {
          Process sshProcess = Runtime.getRuntime().exec(sshCommand);
-         }*/
+         }
     }
 }
\ No newline at end of file

src/main/java/TransientWorker.java

@@ -29,7 +29,11 @@ public class TransientWorker
 
     public void work(String nodeNum) throws KeeperException, InterruptedException {
         addChildZnode(nodeNum);
-        while (true)
+        System.out.println(myName + " is Working...");
+        Thread.sleep(20000);
+        System.out.println(myName + " encountered Critical error happened");
+        throw new RuntimeException(myName + " : Oops");
+        /*while (true)
         {
             System.out.println(myName + " is Working...");
             LockSupport.parkNanos(1000L);
@@ -37,7 +41,7 @@ public class TransientWorker
                 System.out.println(myName + " encountered Critical error happened");
                 throw new RuntimeException(myName + " : Oops");
             }
-        }
+        }*/
     }
 
     private void addChildZnode(String nodeNumber) throws KeeperException, InterruptedException {