replicas

10 files changed, 590 insertions, 359 deletions

diff --git a/src/main/java/derms/Replica1.java b/src/main/java/derms/Replica1.java
new file mode 100644
index 0000000..d7c149d
--- /dev/null
+++ b/src/main/java/derms/Replica1.java
@@ -0,0 +1,90 @@
+package derms;
+
+import derms.net.runicast.ReliableUnicastSender;
+
+import javax.xml.ws.Endpoint;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.util.logging.Logger;
+
+public class Replica1 {
+    private final ReliableUnicastSender<Response> unicastSender;
+    ReplicaManager replicaManager;
+    private final Logger log;
+    private boolean alive = true;
+
+    public Replica1( InetSocketAddress frontEndAddress) throws IOException {
+        this.unicastSender = new ReliableUnicastSender<Response>(frontEndAddress);
+        this.log = Logger.getLogger(getClass().getName());
+    }
+
+
+    public boolean isAlive() {
+        return alive;
+    }
+
+    public void startProcess() {
+        // Simulate the replica process starting.
+        log.info("Replica " + 1 + " started.");
+    }
+
+    public void processRequest(Request request) {
+        // Process the request and create a response.
+        endpoint1 = Endpoint.publish("http://localhost:8080/ws/derms", new DERMSServer("MTL"));
+        endpoint2 = Endpoint.publish("http://localhost:8081/ws/derms", new DERMSServer("QUE"));
+        endpoint3 = Endpoint.publish("http://localhost:8082/ws/derms", new DERMSServer("SHE"));
+
+
+        String responseMessage;
+        switch (request.getFunction()) {
+            case "addResource":
+                responderClient = new ResponderClient(request.getClientID());
+                responseMessage = responderClient.addResource(request.getResourceID(), request.getResourceType(), request.getDuration());
+                break;
+            case "removeResource":
+                responderClient = new ResponderClient(request.getClientID());
+                responseMessage = responderClient.removeResource(request.getResourceID(), request.getDuration());
+                break;
+            case "listResourceAvailability":
+                responderClient = new ResponderClient(request.getClientID());
+                responseMessage = responderClient.listResourceAvailability(request.getResourceType());
+                break;
+            case "requestResource":
+                coordinatorClient = new CoordinatorClient(request.getClientID());
+                responseMessage = coordinatorClient.requestResource(request.getClientID(), request.getResourceID(), request.getDuration());
+                break;
+            case "findResource":
+                coordinatorClient = new CoordinatorClient(request.getClientID());
+                responseMessage = coordinatorClient.findResource(request.getClientID(), request.getResourceType());
+                break;
+            case "returnResource":
+                coordinatorClient = new CoordinatorClient(request.getClientID());
+                responseMessage = coordinatorClient.returnResource(request.getClientID(), request.getResourceID());
+                break;
+            case "swapResource":
+                coordinatorClient = new CoordinatorClient(request.getClientID());
+                responseMessage = coordinatorClient.swapResource(
+                        request.getClientID(),
+                        request.getOldResourceID(),
+                        request.getOldResourceType(),
+                        request.getResourceID(),
+                        request.getResourceType()
+                );
+                break;
+            default:
+                responseMessage = "Unrecognized function: " + request.getFunction();
+                log.severe("Unrecognized function in request: " + request.getFunction());
+                break;
+        }
+
+        Response response = new Response(request.getSequenceNumber(), responseMessage);
+        log.info("Replica " + 1 + " processed request: " + request + ", response: " + response);
+        replicaManager.sendResponseToFE(response);
+    }
+
+    public void restart() {
+        // Restart the replica process.
+        log.warning("Replica " + 1 + " is restarting...");
+        startProcess();
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/derms/ReplicaManager.java b/src/main/java/derms/ReplicaManager.java
new file mode 100644
index 0000000..9725bcb
--- /dev/null
+++ b/src/main/java/derms/ReplicaManager.java
@@ -0,0 +1,115 @@
+package derms;
+import derms.frontend.FEInterface;
+
+import derms.Replica1;
+import derms.Replica2;
+import derms.Replica3;
+import derms.Replica4;
+
+import derms.Request;
+import derms.Response;
+import derms.net.MessagePayload;
+import derms.net.tomulticast.TotalOrderMulticastReceiver;
+import derms.net.runicast.ReliableUnicastSender;
+import derms.net.tomulticast.TotalOrderMulticastSender;
+
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.util.logging.Logger;
+
+public class ReplicaManager {
+    private final int replicaId;
+    private Replica replica;
+    private Response response;
+    private final FEInterface frontEnd;
+    private final Logger log;
+    private ReliableUnicastSender <Response>unicastSender;
+
+    private TotalOrderMulticastReceiver multicastReceiver;
+
+    public ReplicaManager(int replicaId, FEInterface frontEnd) throws IOException {
+        this.replicaId = replicaId;
+        this.frontEnd = frontEnd;
+        this.log = Logger.getLogger(getClass().getName());
+        initReplica();
+        initMulticastReceiver();
+        startHeartbeatThread();
+    }
+
+    private void initReplica() throws IOException {
+        InetSocketAddress frontEndAddress = new InetSocketAddress("localhost", 1999);
+        switch (replicaId)
+        case 1:
+        replica = new Replica1(frontEndAddress);
+        break;
+        case 2:
+        replica = new Replica2( frontEndAddress);
+        break;
+        case 3:
+        replica = new Replica3( frontEndAddress);
+        break;
+        case 4:
+        replica = new Replica4(frontEndAddress);
+        break;
+        replica.startProcess();
+    }
+
+
+
+    private void initMulticastReceiver() throws IOException {
+        InetSocketAddress group = new InetSocketAddress("230.0.0.0", 4446); // Example multicast group and port for receiving requests
+        InetAddress localAddress = InetAddress.getLocalHost(); // Your local address
+        multicastReceiver = new TotalOrderMulticastReceiver<Request>(group, localAddress);
+
+
+        new Thread(() -> {
+            while (true) {
+                try {
+                    MessagePayload receivedPayload = multicastReceiver.receive();
+                    Request request = (Request) receivedPayload;
+                    replica.processRequest(request);
+                } catch (InterruptedException e) {
+                    log.severe("Failed to receive request: " + e.getMessage());
+                    Thread.currentThread().interrupt();
+                } catch (Exception e) {
+                    log.severe("Error processing request: " + e.getMessage());
+                }
+            }
+        }).start();
+    }
+
+
+    private void startHeartbeatThread() {
+        new Thread(() -> {
+            while (true) {
+                if (!replica.isAlive()) {
+                    frontEnd.informRmIsDown(replica.getId());
+                    replica.restart();
+                }
+                try {
+                    Thread.sleep(5000); // Example 5 seconds.
+                } catch (InterruptedException e) {
+                    log.severe("Heartbeat thread interrupted: " + e.getMessage());
+                }
+            }
+        }).start();
+    }
+
+    public void sendResponseToFE(Response response) {
+        try {
+            unicastSender.send(response);
+        } catch (IOException e) {
+            log.severe("Failed to send response to FE: " + e.getMessage());
+        }
+    }
+    public void handleByzantineFailure() {
+        log.severe("Byzantine failure detected in Replica " + replica.getId());
+        replica.restart();
+        frontEnd.informRmHasBug(replica.getId());
+    }
+
+
+
+}
\ No newline at end of file
diff --git a/src/main/java/derms/ReplicaRunner.java b/src/main/java/derms/ReplicaRunner.java
new file mode 100644
index 0000000..a17fbf1
--- /dev/null
+++ b/src/main/java/derms/ReplicaRunner.java
@@ -0,0 +1,28 @@
+package derms;
+import derms.frontend.FEInterface;
+
+import java.io.IOException;
+
+public class ReplicaRunner {
+    public static void main(String[] args) {
+        if (args.length != 1) {
+            System.err.println("Usage: ReplicaManagerRunner <replica_id>");
+            System.exit(1);
+        }
+
+        int replicaId = Integer.parseInt(args[0]);
+        System.out.println("Starting ReplicaManager for Replica " + replicaId);
+
+        try {
+            FEInterface frontEnd = new FE(); // Assume FE implements FEInterface
+            ReplicaManager replicaManager = new ReplicaManager(replicaId, frontEnd);
+
+            // Simulate receiving and handling client requests
+            // Add logic to listen for client requests and forward them to replicaManager
+
+        } catch (IOException e) {
+            System.err.println("Failed to start ReplicaManager: " + e.getMessage());
+            e.printStackTrace();
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/derms/Request.java b/src/main/java/derms/Request.java
index 8dfca56..4132cfa 100644
--- a/src/main/java/derms/Request.java
+++ b/src/main/java/derms/Request.java
@@ -5,9 +5,138 @@ import derms.net.MessagePayload;
 // TODO
 public class Request implements MessagePayload {
 
+
     @Override
     public int hash() {
         // TODO
         return -1;
     }
+
+    private String function = "";
+    private String clientID = "";
+    private String resourceType = "";
+    private String OldResourceType = "";
+    private String resourceID = "";
+    private String OldResourceID = "";
+    private String FeIpAddress = "FE.FE_IP_Address";
+    private int duration = 0;
+    private int sequenceNumber = 0;
+    private String MessageType = "00";
+    private int retryCount = 1;
+
+    public Request(String function, String clientID) {
+        setFunction(function);
+        setClientID(clientID);
+    }
+
+    public Request(int rmNumber, String bugType) {
+        setMessageType(bugType + rmNumber);
+    }
+
+    public String getFunction() {
+        return function;
+    }
+
+    public void setFunction(String function) {
+        this.function = function;
+    }
+
+    public String getClientID() {
+        return clientID;
+    }
+
+    public void setClientID(String clientID) {
+        this.clientID = clientID;
+    }
+
+    public String getResourceType() {
+        return resourceType;
+    }
+
+    public void setResourceType(String resourceType) {
+        this.resourceType = resourceType;
+    }
+
+    public String getOldResourceType() {
+        return OldResourceType;
+    }
+
+    public void setOldResourceType(String OldResourceType) {
+        this.OldResourceType = OldResourceType;
+    }
+
+    public String getResourceID() {
+        return resourceID;
+    }
+
+    public void setResourceID(String resourceID) {
+        this.resourceID = resourceID;
+    }
+
+    public String getOldResourceID() {
+        return OldResourceID;
+    }
+
+    public void setOldResourceID(String OldResourceID) {
+        this.OldResourceID = OldResourceID;
+    }
+
+    public int getDuration() {
+        return duration;
+    }
+
+    public void setDuration(int duration) {
+        this.duration = duration;
+    }
+
+    public String noRequestSendError() {
+        return "request: " + getFunction() + " from " + getClientID() + " not sent";
+    }
+
+    public int getSequenceNumber() {
+        return sequenceNumber;
+    }
+
+    public void setSequenceNumber(int sequenceNumber) {
+        this.sequenceNumber = sequenceNumber;
+    }
+
+    public String getFeIpAddress() {
+        return FeIpAddress;
+    }
+
+    public void setFeIpAddress(String feIpAddress) {
+        FeIpAddress = feIpAddress;
+    }
+
+    public String getMessageType() {
+        return MessageType;
+    }
+
+    public void setMessageType(String messageType) {
+        MessageType = messageType;
+    }
+
+    public boolean haveRetries() {
+        return retryCount > 0;
+    }
+
+    public void countRetry() {
+        retryCount--;
+    }
+
+    //Message Format: Sequence_id;FrontIpAddress;Message_Type;function(addResource,...);userID; newEventID;newEventType; oldEventID; oldEventType;bookingCapacity
+    @Override
+    public String toString() {
+        return getSequenceNumber() + ";" +
+                getFeIpAddress().toUpperCase() + ";" +
+                getMessageType().toUpperCase() + ";" +
+                getFunction().toUpperCase() + ";" +
+                getClientID().toUpperCase() + ";" +
+                getResourceID().toUpperCase() + ";" +
+                getResourceType().toUpperCase() + ";" +
+                getOldResourceID().toUpperCase() + ";" +
+                getOldResourceType().toUpperCase() + ";" +
+                getDuration();
+    }
 }
diff --git a/src/main/java/derms/Response.java b/src/main/java/derms/Response.java
index 3832253..036ea9d 100644
--- a/src/main/java/derms/Response.java
+++ b/src/main/java/derms/Response.java
@@ -10,4 +10,147 @@ public class Response implements MessagePayload {
         // TODO
         return  -1;
     }
+    private int sequenceID = 0;
+    private String response = "";
+    private int rmNumber = 0;
+    private String function = "";
+    private String userID = "";
+    private String newResourceID = "";
+    private String newResourceType = "";
+    private String oldResourceID = "";
+    private String oldResourceType = "";
+    private int duration = 0;
+    private String udpMessage = "";
+    private boolean isSuccess = false;
+
+    public Response(String udpMessage) {
+        setUdpMessage(udpMessage.trim());
+        String[] messageParts = getUdpMessage().split(";");
+        setSequenceID(Integer.parseInt(messageParts[0]));
+        setResponse(messageParts[1].trim());
+        setRmNumber(messageParts[2]);
+        setFunction(messageParts[3]);
+        setUserID(messageParts[4]);
+        setNewResourceID(messageParts[5]);
+        setNewResourceType(messageParts[6]);
+        setOldResourceID(messageParts[7]);
+        setOldResourceType(messageParts[8]);
+        setDuration(Integer.parseInt(messageParts[9]));
+    }
+
+    public int getSequenceID() {
+        return sequenceID;
+    }
+
+    public void setSequenceID(int sequenceID) {
+        this.sequenceID = sequenceID;
+    }
+
+    public String getResponse() {
+        return response;
+    }
+
+    public void setResponse(String response) {
+        isSuccess = response.contains("Success:");
+        this.response = response;
+    }
+
+    public int getRmNumber() {
+        return rmNumber;
+    }
+
+    public void setRmNumber(String rmNumber) {
+        if (rmNumber.equalsIgnoreCase("RM1")) {
+            this.rmNumber = 1;
+        } else if (rmNumber.equalsIgnoreCase("RM2")) {
+            this.rmNumber = 2;
+        } else if (rmNumber.equalsIgnoreCase("RM3")) {
+            this.rmNumber = 3;
+        } else {
+            this.rmNumber = 0;
+        }
+    }
+
+    public String getFunction() {
+        return function;
+    }
+
+    public void setFunction(String function) {
+        this.function = function;
+    }
+
+    public String getUserID() {
+        return userID;
+    }
+
+    public void setUserID(String userID) {
+        this.userID = userID;
+    }
+
+    public String getNewResourceID() {
+        return newResourceID;
+    }
+
+    public void setNewResourceID(String newEventID) {
+        this.newResourceID = newEventID;
+    }
+
+    public String getNewResourceType() {
+        return newResourceType;
+    }
+
+    public void setNewResourceType(String newEventType) {
+        this.newResourceType = newEventType;
+    }
+
+    public String getOldResourceID() {
+        return oldResourceID;
+    }
+
+    public void setOldResourceID(String oldEventID) {
+        this.oldResourceID = oldEventID;
+    }
+
+    public String getOldResourceType() {
+        return oldResourceType;
+    }
+
+    public void setOldResourceType(String oldEventType) {
+        this.oldResourceType = oldEventType;
+    }
+
+    public int getDuration() {
+        return duration;
+    }
+
+    public void setDuration(int bookingCapacity) {
+        this.duration = bookingCapacity;
+    }
+
+    public String getUdpMessage() {
+        return udpMessage;
+    }
+
+    public void setUdpMessage(String udpMessage) {
+        this.udpMessage = udpMessage;
+    }
+
+    public boolean isSuccess() {
+        return isSuccess;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj != null) {
+            if (obj instanceof RmResponse) {
+                RmResponse obj1 = (RmResponse) obj;
+                return obj1.getFunction().equalsIgnoreCase(this.getFunction())
+                        && obj1.getSequenceID() == this.getSequenceID()
+                        && obj1.getUserID().equalsIgnoreCase(this.getUserID())
+                        && obj1.isSuccess() == this.isSuccess();
+//                        && obj1.getResponse().equalsIgnoreCase(this.getResponse());
+            }
+        }
+        return false;
+    }
 }
diff --git a/src/main/java/derms/frontend/DERMSServerImpl.java b/src/main/java/derms/frontend/DERMSServerImpl.java
index 67dd8c5..4008278 100644
--- a/src/main/java/derms/frontend/DERMSServerImpl.java
+++ b/src/main/java/derms/frontend/DERMSServerImpl.java
@@ -21,7 +21,8 @@ import javax.jws.soap.SOAPBinding.Style;
 //import constants.PortConstants;
 //import validation.ValidationService;
 //import interfaces.DERMSInterface;
-
+import  derms.Request;
+import  derms.Response;
 @WebService(endpointInterface = "derms.frontend.DERMSInterface")
 public class DERMSServerImpl implements DERMSInterface {
 	
@@ -38,7 +39,7 @@ public class DERMSServerImpl implements DERMSInterface {
     private long startTime;
     private CountDownLatch latch;
     private FEInterface inter = null;
-    private final List<RmResponse> responses = new ArrayList<>();
+    private final List<Response> responses = new ArrayList<>();
 
     public DERMSServerImpl() {
         super();
@@ -51,72 +52,72 @@ public class DERMSServerImpl implements DERMSInterface {
     
 	@Override
     public synchronized String addResource(String resourceID, String resourceName, int duration) {
-        MyRequest myRequest = new MyRequest("addResource", "");
-        myRequest.setResourceID(resourceID);
-        myRequest.setResourceType(resourceName);
-        myRequest.setDuration(duration);
-        myRequest.setSequenceNumber(sendUdpUnicastToSequencer(myRequest));
-        System.out.println("FE Implementation:addEvent>>>" + myRequest.toString());
-        return validateResponses(myRequest);
+        Request request = new Request("addResource", "");
+        request.setResourceID(resourceID);
+        request.setResourceType(resourceName);
+        request.setDuration(duration);
+        request.setSequenceNumber(sendUdpUnicastToSequencer(request));
+        System.out.println("FE Implementation:addEvent>>>" + request.toString());
+        return validateResponses(request);
     }
 
 	@Override
     public synchronized String removeResource(String resourceID, int duration) {
-        MyRequest myRequest = new MyRequest("removeResource", "");
-        myRequest.setResourceID(resourceID);
-        myRequest.setDuration(duration);
-        myRequest.setSequenceNumber(sendUdpUnicastToSequencer(myRequest));
-        System.out.println("FE Implementation:removeEvent>>>" + myRequest.toString());
-        return validateResponses(myRequest);
+        Request request = new Request("removeResource", "");
+        request.setResourceID(resourceID);
+        request.setDuration(duration);
+        request.setSequenceNumber(sendUdpUnicastToSequencer(request));
+        System.out.println("FE Implementation:removeEvent>>>" + request.toString());
+        return validateResponses(request);
     }
 
 	@Override
     public synchronized String listResourceAvailability(String resourceName) {
-        MyRequest myRequest = new MyRequest("listEventAvailability", "");
-        myRequest.setResourceType(resourceName);
-        myRequest.setSequenceNumber(sendUdpUnicastToSequencer(myRequest));
-        System.out.println("FE Implementation:listEventAvailability>>>" + myRequest.toString());
-        return validateResponses(myRequest);
+        Request request = new Request("listEventAvailability", "");
+        request.setResourceType(resourceName);
+        request.setSequenceNumber(sendUdpUnicastToSequencer(request));
+        System.out.println("FE Implementation:listEventAvailability>>>" + request.toString());
+        return validateResponses(request);
     }
 
 	@Override
     public synchronized String requestResource(String coordinatorID, String resourceID, int duration) {
-        MyRequest myRequest = new MyRequest("requestResource", coordinatorID);
-        myRequest.setResourceID(resourceID);
-        myRequest.setDuration(duration);
-        myRequest.setSequenceNumber(sendUdpUnicastToSequencer(myRequest));
-        System.out.println("FE Implementation:bookEvent>>>" + myRequest.toString());
-        return validateResponses(myRequest);
+        Request request = new Request("requestResource", coordinatorID);
+        request.setResourceID(resourceID);
+        request.setDuration(duration);
+        request.setSequenceNumber(sendUdpUnicastToSequencer(request));
+        System.out.println("FE Implementation:bookEvent>>>" + request.toString());
+        return validateResponses(request);
     }
 	
 	@Override
     public synchronized String findResource(String coordinatorID, String resourceName) {
-        MyRequest myRequest = new MyRequest("findResource", coordinatorID);
-        myRequest.setResourceType(resourceName);
-        myRequest.setSequenceNumber(sendUdpUnicastToSequencer(myRequest));
-        System.out.println("FE Implementation:bookEvent>>>" + myRequest.toString());
-        return validateResponses(myRequest);
+        Request request = new Request("findResource", coordinatorID);
+        request.setResourceType(resourceName);
+        request.setSequenceNumber(sendUdpUnicastToSequencer(request));
+        System.out.println("FE Implementation:bookEvent>>>" + request.toString());
+        return validateResponses(request);
     }
 	
 	@Override
     public synchronized String returnResource(String coordinatorID, String resourceID) {
-        MyRequest myRequest = new MyRequest("findResource", coordinatorID);
-        myRequest.setResourceID(resourceID);
-        myRequest.setSequenceNumber(sendUdpUnicastToSequencer(myRequest));
-        System.out.println("FE Implementation:bookEvent>>>" + myRequest.toString());
-        return validateResponses(myRequest);
+        Request request = new Request("findResource", coordinatorID);
+        request.setResourceID(resourceID);
+        request.setSequenceNumber(sendUdpUnicastToSequencer(request));
+        System.out.println("FE Implementation:bookEvent>>>" + request.toString());
+        return validateResponses(request);
     }
 
 	@Override
     public synchronized String swapResource(String coordinatorID, String oldResourceID, String oldResourceType, String newResourceID, String newResourceType) {
-        MyRequest myRequest = new MyRequest("swapResource", coordinatorID);
-        myRequest.setResourceID(newResourceID);
-        myRequest.setResourceType(newResourceType);
-        myRequest.setOldResourceID(oldResourceID);
-        myRequest.setOldResourceType(oldResourceType);
-        myRequest.setSequenceNumber(sendUdpUnicastToSequencer(myRequest));
-        System.out.println("FE Implementation:swapEvent>>>" + myRequest.toString());
-        return validateResponses(myRequest);
+        Request request = new Request("swapResource", coordinatorID);
+        request.setResourceID(newResourceID);
+        request.setResourceType(newResourceType);
+        request.setOldResourceID(oldResourceID);
+        request.setOldResourceType(oldResourceType);
+        request.setSequenceNumber(sendUdpUnicastToSequencer(request));
+        System.out.println("FE Implementation:swapEvent>>>" + request.toString());
+        return validateResponses(request);
     }
 	
     public void waitForResponse() {
@@ -128,26 +129,26 @@ public class DERMSServerImpl implements DERMSInterface {
             }
         } catch (InterruptedException e) {
             e.printStackTrace();
-//            inter.sendRequestToSequencer(myRequest);
+//            inter.sendRequestToSequencer(request);
         }
 //         check result and react correspondingly
     }
 	
-   private String validateResponses(MyRequest myRequest) {
+   private String validateResponses(Request request) {
         String resp;
         switch ((int) latch.getCount()) {
             case 0:
             case 1:
             case 2:
             case 3:
-                resp = findMajorityResponse(myRequest);
+                resp = findMajorityResponse(request);
                 break;
             case 4:
                 resp = "Fail: No response from any server";
                 System.out.println(resp);
-                if (myRequest.haveRetries()) {
-                    myRequest.countRetry();
-                    resp = retryRequest(myRequest);
+                if (request.haveRetries()) {
+                    request.countRetry();
+                    resp = retryRequest(request);
                 }
                 rmDown(1);
                 rmDown(2);
@@ -155,20 +156,20 @@ public class DERMSServerImpl implements DERMSInterface {
                 rmDown(4);
                 break;
             default:
-                resp = "Fail: " + myRequest.noRequestSendError();
+                resp = "Fail: " + request.noRequestSendError();
                 break;
         }
         System.out.println("FE Implementation:validateResponses>>>Responses remain:" + latch.getCount() + " >>>Response to be sent to client " + resp);
         return resp;
     }
    
-   private String findMajorityResponse(MyRequest myRequest) {
-       RmResponse res1 = null;
-       RmResponse res2 = null;
-       RmResponse res3 = null;
-       RmResponse res4 = null;
-       for (RmResponse response :responses) {
-           if (response.getSequenceID() == myRequest.getSequenceNumber()) {
+   private String findMajorityResponse(Request request) {
+       Response res1 = null;
+       Response res2 = null;
+       Response res3 = null;
+       Response res4 = null;
+       for (Response response :responses) {
+           if (response.getSequenceID() == request.getSequenceNumber()) {
                switch (response.getRmNumber()) {
                    case 1:
                        res1 = response;
@@ -197,12 +198,12 @@ public class DERMSServerImpl implements DERMSInterface {
        if (res4 == null) rmDown(4);
 
        // Majority voting logic
-       List<RmResponse> validResponses = Arrays.asList(res1, res2, res3, res4).stream()
+       List<Response> validResponses = Arrays.asList(res1, res2, res3, res4).stream()
                                               .filter(Objects::nonNull)
                                               .collect(Collectors.toList());
 
        Map<String, Long> responseCounts = validResponses.stream()
-               .collect(Collectors.groupingBy(RmResponse::getResponse, Collectors.counting()));
+               .collect(Collectors.groupingBy(Response::getResponse, Collectors.counting()));
 
        // Find the response with the highest count
        Optional<Map.Entry<String, Long>> majorityEntry = responseCounts.entrySet().stream()
@@ -319,7 +320,7 @@ public class DERMSServerImpl implements DERMSInterface {
        System.out.println("FE Implementation:notifyOKCommandReceived>>>Response Received: Remaining responses" + latch.getCount());
    }
 
-   public void addReceivedResponse(RmResponse res) {
+   public void addReceivedResponse(Response res) {
        long endTime = System.nanoTime();
        responseTime = (endTime - startTime) / 1000000;
        System.out.println("Current Response time is: " + responseTime);
@@ -327,22 +328,22 @@ public class DERMSServerImpl implements DERMSInterface {
        notifyOKCommandReceived();
    }
 
-   private int sendUdpUnicastToSequencer(MyRequest myRequest) {
+   private int sendUdpUnicastToSequencer(Request request) {
        startTime = System.nanoTime();
-       int sequenceNumber = inter.sendRequestToSequencer(myRequest);
-       myRequest.setSequenceNumber(sequenceNumber);
+       int sequenceNumber = inter.sendRequestToSequencer(request);
+       request.setSequenceNumber(sequenceNumber);
        latch = new CountDownLatch(4);
        waitForResponse();
        return sequenceNumber;
    }
 
-   private String retryRequest(MyRequest myRequest) {
-       System.out.println("FE Implementation:retryRequest>>>" + myRequest.toString());
+   private String retryRequest(Request request) {
+       System.out.println("FE Implementation:retryRequest>>>" + request.toString());
        startTime = System.nanoTime();
-       inter.retryRequest(myRequest);
+       inter.retryRequest(request);
        latch = new CountDownLatch(4);
        waitForResponse();
-       return validateResponses(myRequest);
+       return validateResponses(request);
    }
 
 	
diff --git a/src/main/java/derms/frontend/FE.java b/src/main/java/derms/frontend/FE.java
index e49dd61..decea07 100644
--- a/src/main/java/derms/frontend/FE.java
+++ b/src/main/java/derms/frontend/FE.java
@@ -7,6 +7,8 @@ import java.net.InetAddress;
 import java.net.SocketException;
 
 import javax.xml.ws.Endpoint;
+import  derms.Request;
+import  derms.Response;
 
 //import constants.Constants;
 
@@ -20,8 +22,8 @@ public class FE {
     private static final int RM_Multicast_Port = 1234;
     public static String FE_Address = "http://localhost:8067/service/FE";
     private static final String FE_IP_Address = "";
-    
-    
+
+
 //    public static String FE_IP_Address = "localhost";
 
     public static void main(String[] args) {
@@ -30,7 +32,7 @@ public class FE {
                 @Override
                 public void informRmHasBug(int RmNumber) {
 //                    String errorMessage = new MyRequest(RmNumber, "1").toString();
-                    MyRequest errorMessage = new MyRequest(RmNumber, "1");
+                    Request errorMessage = new Request(RmNumber, "1");
                     System.out.println("Rm:" + RmNumber + "has bug");
 //                    sendMulticastFaultMessageToRms(errorMessage);
                     sendUnicastToSequencer(errorMessage);
@@ -39,21 +41,21 @@ public class FE {
                 @Override
                 public void informRmIsDown(int RmNumber) {
 //                    String errorMessage = new MyRequest(RmNumber, "2").toString();
-                    MyRequest errorMessage = new MyRequest(RmNumber, "2");
+                    Request errorMessage = new Request(RmNumber, "2");
                     System.out.println("Rm:" + RmNumber + "is down");
 //                    sendMulticastFaultMessageToRms(errorMessage);
                     sendUnicastToSequencer(errorMessage);
                 }
 
                 @Override
-                public int sendRequestToSequencer(MyRequest myRequest) {
+                public int sendRequestToSequencer(Request myRequest) {
                     return sendUnicastToSequencer(myRequest);
                 }
 
                 @Override
-                public void retryRequest(MyRequest myRequest) {
+                public void retryRequest(Request request) {
                     System.out.println("No response from all Rms, Retrying request...");
-                    sendUnicastToSequencer(myRequest);
+                    sendUnicastToSequencer(request);
                 }
             };
             DERMSServerImpl servant = new DERMSServerImpl(inter);
@@ -75,7 +77,7 @@ public class FE {
 
     }
 
-    private static int sendUnicastToSequencer(MyRequest requestFromClient) {
+    private static int sendUnicastToSequencer(Request requestFromClient) {
         DatagramSocket aSocket = null;
         String dataFromClient = requestFromClient.toString();
         System.out.println("FE:sendUnicastToSequencer>>>" + dataFromClient);
@@ -154,7 +156,7 @@ public class FE {
                 String sentence = new String(response.getData(), 0,
                         response.getLength()).trim();
                 System.out.println("FE:Response received from Rm>>>" + sentence);
-                RmResponse rmResponse = new RmResponse(sentence);
+                Response rmResponse = new Response(sentence);
 //                String[] parts = sentence.split(";");
 
                 System.out.println("Adding response to FrontEndImplementation:");
diff --git a/src/main/java/derms/frontend/FEInterface.java b/src/main/java/derms/frontend/FEInterface.java
index 5a4e6f1..292f960 100644
--- a/src/main/java/derms/frontend/FEInterface.java
+++ b/src/main/java/derms/frontend/FEInterface.java
@@ -1,11 +1,12 @@
 package derms.frontend;
+import  derms.Request;
 
 public interface FEInterface {
-    void informRmHasBug(int RmNumber);
+    void informRmHasBug(int replicaId);
 
-    void informRmIsDown(int RmNumber);
+    void informRmIsDown(int replicaId);
 
-    int sendRequestToSequencer(MyRequest myRequest);
+    int sendRequestToSequencer(Request request);
 
-    void retryRequest(MyRequest myRequest);
+    void retryRequest(Request request);
 }
\ No newline at end of file
diff --git a/src/main/java/derms/frontend/MyRequest.java b/src/main/java/derms/frontend/MyRequest.java
deleted file mode 100644
index b0f2758..0000000
--- a/src/main/java/derms/frontend/MyRequest.java
+++ /dev/null
@@ -1,131 +0,0 @@
-package derms.frontend;
-
-public class MyRequest {
-	   private String function = "";
-	    private String clientID = "";
-	    private String resourceType = "";
-	    private String OldResourceType = "";
-	    private String resourceID = "";
-	    private String OldResourceID = "";
-	    private String FeIpAddress = "FE.FE_IP_Address";
-	    private int duration = 0;
-	    private int sequenceNumber = 0;
-	    private String MessageType = "00";
-	    private int retryCount = 1;
-
-	    public MyRequest(String function, String clientID) {
-	        setFunction(function);
-	        setClientID(clientID);
-	    }
-
-	    public MyRequest(int rmNumber, String bugType) {
-	        setMessageType(bugType + rmNumber);
-	    }
-
-	    public String getFunction() {
-	        return function;
-	    }
-
-	    public void setFunction(String function) {
-	        this.function = function;
-	    }
-
-	    public String getClientID() {
-	        return clientID;
-	    }
-
-	    public void setClientID(String clientID) {
-	        this.clientID = clientID;
-	    }
-
-	    public String getResourceType() {
-	        return resourceType;
-	    }
-
-	    public void setResourceType(String resourceType) {
-	        this.resourceType = resourceType;
-	    }
-
-	    public String getOldResourceType() {
-	        return OldResourceType;
-	    }
-
-	    public void setOldResourceType(String OldResourceType) {
-	        this.OldResourceType = OldResourceType;
-	    }
-
-	    public String getResourceID() {
-	        return resourceID;
-	    }
-
-	    public void setResourceID(String resourceID) {
-	        this.resourceID = resourceID;
-	    }
-
-	    public String getOldResourceID() {
-	        return OldResourceID;
-	    }
-
-	    public void setOldResourceID(String OldResourceID) {
-	        this.OldResourceID = OldResourceID;
-	    }
-
-	    public int getDuration() {
-	        return duration;
-	    }
-
-	    public void setDuration(int duration) {
-	        this.duration = duration;
-	    }
-
-	    public String noRequestSendError() {
-	        return "request: " + getFunction() + " from " + getClientID() + " not sent";
-	    }
-
-	    public int getSequenceNumber() {
-	        return sequenceNumber;
-	    }
-
-	    public void setSequenceNumber(int sequenceNumber) {
-	        this.sequenceNumber = sequenceNumber;
-	    }
-
-	    public String getFeIpAddress() {
-	        return FeIpAddress;
-	    }
-
-	    public void setFeIpAddress(String feIpAddress) {
-	        FeIpAddress = feIpAddress;
-	    }
-
-	    public String getMessageType() {
-	        return MessageType;
-	    }
-
-	    public void setMessageType(String messageType) {
-	        MessageType = messageType;
-	    }
-
-	    public boolean haveRetries() {
-	        return retryCount > 0;
-	    }
-
-	    public void countRetry() {
-	        retryCount--;
-	    }
-
-	    //Message Format: Sequence_id;FrontIpAddress;Message_Type;function(addResource,...);userID; newEventID;newEventType; oldEventID; oldEventType;bookingCapacity
-	    @Override
-	    public String toString() {
-	        return getSequenceNumber() + ";" +
-	                getFeIpAddress().toUpperCase() + ";" +
-	                getMessageType().toUpperCase() + ";" +
-	                getFunction().toUpperCase() + ";" +
-	                getClientID().toUpperCase() + ";" +
-	                getResourceID().toUpperCase() + ";" +
-	                getResourceType().toUpperCase() + ";" +
-	                getOldResourceID().toUpperCase() + ";" +
-	                getOldResourceType().toUpperCase() + ";" +
-	                getDuration();
-	    }
-}
diff --git a/src/main/java/derms/frontend/RmResponse.java b/src/main/java/derms/frontend/RmResponse.java
deleted file mode 100644
index f693375..0000000
--- a/src/main/java/derms/frontend/RmResponse.java
+++ /dev/null
@@ -1,147 +0,0 @@
-package derms.frontend;
-
-public class RmResponse {
-    private int sequenceID = 0;
-    private String response = "";
-    private int rmNumber = 0;
-    private String function = "";
-    private String userID = "";
-    private String newResourceID = "";
-    private String newResourceType = "";
-    private String oldResourceID = "";
-    private String oldResourceType = "";
-    private int duration = 0;
-    private String udpMessage = "";
-    private boolean isSuccess = false;
-
-    public RmResponse(String udpMessage) {
-        setUdpMessage(udpMessage.trim());
-        String[] messageParts = getUdpMessage().split(";");
-        setSequenceID(Integer.parseInt(messageParts[0]));
-        setResponse(messageParts[1].trim());
-        setRmNumber(messageParts[2]);
-        setFunction(messageParts[3]);
-        setUserID(messageParts[4]);
-        setNewResourceID(messageParts[5]);
-        setNewResourceType(messageParts[6]);
-        setOldResourceID(messageParts[7]);
-        setOldResourceType(messageParts[8]);
-        setDuration(Integer.parseInt(messageParts[9]));
-    }
-
-    public int getSequenceID() {
-        return sequenceID;
-    }
-
-    public void setSequenceID(int sequenceID) {
-        this.sequenceID = sequenceID;
-    }
-
-    public String getResponse() {
-        return response;
-    }
-
-    public void setResponse(String response) {
-        isSuccess = response.contains("Success:");
-        this.response = response;
-    }
-
-    public int getRmNumber() {
-        return rmNumber;
-    }
-
-    public void setRmNumber(String rmNumber) {
-        if (rmNumber.equalsIgnoreCase("RM1")) {
-            this.rmNumber = 1;
-        } else if (rmNumber.equalsIgnoreCase("RM2")) {
-            this.rmNumber = 2;
-        } else if (rmNumber.equalsIgnoreCase("RM3")) {
-            this.rmNumber = 3;
-        } else {
-            this.rmNumber = 0;
-        }
-    }
-
-    public String getFunction() {
-        return function;
-    }
-
-    public void setFunction(String function) {
-        this.function = function;
-    }
-
-    public String getUserID() {
-        return userID;
-    }
-
-    public void setUserID(String userID) {
-        this.userID = userID;
-    }
-
-    public String getNewResourceID() {
-        return newResourceID;
-    }
-
-    public void setNewResourceID(String newEventID) {
-        this.newResourceID = newEventID;
-    }
-
-    public String getNewResourceType() {
-        return newResourceType;
-    }
-
-    public void setNewResourceType(String newEventType) {
-        this.newResourceType = newEventType;
-    }
-
-    public String getOldResourceID() {
-        return oldResourceID;
-    }
-
-    public void setOldResourceID(String oldEventID) {
-        this.oldResourceID = oldEventID;
-    }
-
-    public String getOldResourceType() {
-        return oldResourceType;
-    }
-
-    public void setOldResourceType(String oldEventType) {
-        this.oldResourceType = oldEventType;
-    }
-
-    public int getDuration() {
-        return duration;
-    }
-
-    public void setDuration(int bookingCapacity) {
-        this.duration = bookingCapacity;
-    }
-
-    public String getUdpMessage() {
-        return udpMessage;
-    }
-
-    public void setUdpMessage(String udpMessage) {
-        this.udpMessage = udpMessage;
-    }
-
-    public boolean isSuccess() {
-        return isSuccess;
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-        if (obj != null) {
-            if (obj instanceof RmResponse) {
-                RmResponse obj1 = (RmResponse) obj;
-                return obj1.getFunction().equalsIgnoreCase(this.getFunction())
-                        && obj1.getSequenceID() == this.getSequenceID()
-                        && obj1.getUserID().equalsIgnoreCase(this.getUserID())
-                        && obj1.isSuccess() == this.isSuccess();
-//                        && obj1.getResponse().equalsIgnoreCase(this.getResponse());
-            }
-        }
-        return false;
-    }
-}