diff --git a/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/AqlTranslator.java b/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/AqlTranslator.java
index 9fbb24a..9e628c2 100644
--- a/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/AqlTranslator.java
+++ b/asterix-app/src/main/java/edu/uci/ics/asterix/aql/translator/AqlTranslator.java
@@ -568,14 +568,20 @@
         if (allNodesNodegroup) {
             nodegroupName = MetadataConstants.METADATA_DEFAULT_NODEGROUP_NAME;
         } else {
-            Random random = new Random();
             Set<String> nodeNames = AsterixAppContextInfo.getInstance().getMetadataProperties().getNodeNames();
+            String metadataNodeName = AsterixAppContextInfo.getInstance().getMetadataProperties().getMetadataNodeName();
+            List<String> selectedNodes = new ArrayList<String>();
+            selectedNodes.add(metadataNodeName);
+            nodeNames.remove(metadataNodeName);
+            nodegroupCardinality--;
+
+            Random random = new Random();
             String[] nodes = nodeNames.toArray(new String[] {});
             int[] b = new int[nodeNames.size()];
             for (int i = 0; i < b.length; i++) {
                 b[i] = i;
             }
-            List<String> selectedNodes = new ArrayList<String>();
+
             for (int i = 0; i < nodegroupCardinality; i++) {
                 int selected = i + random.nextInt(nodeNames.size() - i);
                 int selNodeIndex = b[selected];
diff --git a/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/ClusterLifecycleListener.java b/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/ClusterLifecycleListener.java
index 4f355f8..cebc710 100644
--- a/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/ClusterLifecycleListener.java
+++ b/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/ClusterLifecycleListener.java
@@ -14,16 +14,26 @@
  */
 package edu.uci.ics.asterix.hyracks.bootstrap;
 
+import java.util.ArrayList;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import edu.uci.ics.asterix.common.exceptions.AsterixException;
+import edu.uci.ics.asterix.event.schema.cluster.Node;
 import edu.uci.ics.asterix.metadata.api.IClusterEventsSubscriber;
 import edu.uci.ics.asterix.metadata.api.IClusterManagementWork;
+import edu.uci.ics.asterix.metadata.cluster.AddNodeWork;
+import edu.uci.ics.asterix.metadata.cluster.AddNodeWorkResponse;
 import edu.uci.ics.asterix.metadata.cluster.ClusterManager;
+import edu.uci.ics.asterix.metadata.cluster.IClusterManagementWorkResponse;
+import edu.uci.ics.asterix.metadata.cluster.IClusterManagementWorkResponse.Status;
+import edu.uci.ics.asterix.metadata.cluster.RemoveNodeWork;
+import edu.uci.ics.asterix.metadata.cluster.RemoveNodeWorkResponse;
 import edu.uci.ics.asterix.om.util.AsterixClusterProperties;
 import edu.uci.ics.hyracks.api.application.IClusterLifecycleListener;
 
@@ -31,15 +41,26 @@
 
     private static final Logger LOGGER = Logger.getLogger(ClusterLifecycleListener.class.getName());
 
+    private static final LinkedBlockingQueue<Set<IClusterManagementWork>> workRequestQueue = new LinkedBlockingQueue<Set<IClusterManagementWork>>();
+
+    private static ClusterWorkExecutor eventHandler = new ClusterWorkExecutor(workRequestQueue);
+
+    private static List<IClusterManagementWorkResponse> pendingWorkResponses = new ArrayList<IClusterManagementWorkResponse>();
+
     public static ClusterLifecycleListener INSTANCE = new ClusterLifecycleListener();
 
     private ClusterLifecycleListener() {
         Thread t = new Thread(eventHandler);
+        if (LOGGER.isLoggable(Level.INFO)) {
+            LOGGER.info("Starting cluster event handler");
+        }
         t.start();
     }
 
-    private static final LinkedBlockingQueue<Set<IClusterManagementWork>> outbox = new LinkedBlockingQueue<Set<IClusterManagementWork>>();
-    private static ClusterEventHandler eventHandler = new ClusterEventHandler(outbox);
+    public enum ClusterEventType {
+        NODE_JOIN,
+        NODE_FAILURE
+    }
 
     @Override
     public void notifyNodeJoin(String nodeId, Map<String, String> ncConfiguration) {
@@ -47,6 +68,20 @@
             LOGGER.info("NC: " + nodeId + " joined");
         }
         AsterixClusterProperties.INSTANCE.addNCConfiguration(nodeId, ncConfiguration);
+        Set<String> nodeAddition = new HashSet<String>();
+        nodeAddition.add(nodeId);
+        updateProgress(ClusterEventType.NODE_JOIN, nodeAddition);
+        Set<IClusterEventsSubscriber> subscribers = ClusterManager.INSTANCE.getRegisteredClusterEventSubscribers();
+        Set<IClusterManagementWork> work = new HashSet<IClusterManagementWork>();
+        for (IClusterEventsSubscriber sub : subscribers) {
+            Set<IClusterManagementWork> workRequest = sub.notifyNodeJoin(nodeId);
+            if (workRequest != null && !workRequest.isEmpty()) {
+                work.addAll(workRequest);
+            }
+        }
+        if (!work.isEmpty()) {
+            executeWorkSet(work);
+        }
 
     }
 
@@ -57,19 +92,112 @@
             }
             AsterixClusterProperties.INSTANCE.removeNCConfiguration(deadNode);
         }
+        updateProgress(ClusterEventType.NODE_FAILURE, deadNodeIds);
         Set<IClusterEventsSubscriber> subscribers = ClusterManager.INSTANCE.getRegisteredClusterEventSubscribers();
         Set<IClusterManagementWork> work = new HashSet<IClusterManagementWork>();
         for (IClusterEventsSubscriber sub : subscribers) {
-            work.addAll(sub.notifyNodeFailure(deadNodeIds));
+            Set<IClusterManagementWork> workRequest = sub.notifyNodeFailure(deadNodeIds);
+            if (workRequest != null && !workRequest.isEmpty()) {
+                work.addAll(workRequest);
+            }
         }
+        if (!work.isEmpty()) {
+            executeWorkSet(work);
+        }
+    }
 
+    private void submitWork(Set<IClusterManagementWork> work) {
         try {
-            outbox.put(work);
+            workRequestQueue.put(work);
         } catch (InterruptedException e) {
             if (LOGGER.isLoggable(Level.WARNING)) {
                 LOGGER.warning("Interrupted :" + e.getMessage());
             }
         }
+    }
+
+    private void updateProgress(ClusterEventType eventType, Set<String> nodeIds) {
+        List<IClusterManagementWorkResponse> completedResponses = new ArrayList<IClusterManagementWorkResponse>();
+        boolean isComplete = false;
+        for (IClusterManagementWorkResponse resp : pendingWorkResponses) {
+            switch (eventType) {
+                case NODE_FAILURE:
+                    isComplete = ((RemoveNodeWorkResponse) resp).updateProgress(nodeIds);
+                    if (isComplete) {
+                        resp.setStatus(Status.SUCCESS);
+                        resp.getWork().getSourceSubscriber().notifyRequestCompletion(resp);
+                        completedResponses.add(resp);
+                    }
+                    break;
+
+                case NODE_JOIN:
+                    isComplete = ((AddNodeWorkResponse) resp).updateProgress(nodeIds.iterator().next());
+                    if (isComplete) {
+                        resp.setStatus(Status.SUCCESS);
+                        resp.getWork().getSourceSubscriber().notifyRequestCompletion(resp);
+                        completedResponses.add(resp);
+                    }
+                    break;
+            }
+        }
+        pendingWorkResponses.removeAll(completedResponses);
+    }
+
+    private void executeWorkSet(Set<IClusterManagementWork> workSet) {
+        int nodesToAdd = 0;
+        Set<String> nodesToRemove = new HashSet<String>();
+        Set<AddNodeWork> nodeAdditionRequests = new HashSet<AddNodeWork>();
+        Set<IClusterManagementWork> nodeRemovalRequests = new HashSet<IClusterManagementWork>();
+        for (IClusterManagementWork w : workSet) {
+            switch (w.getClusterManagementWorkType()) {
+                case ADD_NODE:
+                    if (nodesToAdd < ((AddNodeWork) w).getNumberOfNodes()) {
+                        nodesToAdd = ((AddNodeWork) w).getNumberOfNodes();
+                    }
+                    nodeAdditionRequests.add((AddNodeWork) w);
+                    break;
+                case REMOVE_NODE:
+                    nodesToRemove.addAll(((RemoveNodeWork) w).getNodesToBeRemoved());
+                    nodeRemovalRequests.add(w);
+                    RemoveNodeWorkResponse response = new RemoveNodeWorkResponse((RemoveNodeWork) w, Status.IN_PROGRESS);
+                    pendingWorkResponses.add(response);
+                    break;
+            }
+        }
+
+        List<String> addedNodes = new ArrayList<String>();
+        String asterixInstanceName = AsterixClusterProperties.INSTANCE.getCluster().getInstanceName();
+        for (int i = 0; i < nodesToAdd; i++) {
+            Node node = AsterixClusterProperties.INSTANCE.getAvailableSubstitutionNode();
+            if (node != null) {
+                try {
+                    ClusterManager.INSTANCE.addNode(node);
+                    addedNodes.add(asterixInstanceName + "_" + node.getId());
+                    if (LOGGER.isLoggable(Level.INFO)) {
+                        LOGGER.info("Added NC at:" + node.getId());
+                    }
+                } catch (AsterixException e) {
+                    if (LOGGER.isLoggable(Level.WARNING)) {
+                        LOGGER.warning("Unable to add NC at:" + node.getId());
+                    }
+                    e.printStackTrace();
+                }
+            } else {
+                if (LOGGER.isLoggable(Level.WARNING)) {
+                    LOGGER.warning("Unable to add NC: no more available nodes");
+                }
+            }
+        }
+
+        for (AddNodeWork w : nodeAdditionRequests) {
+            int n = w.getNumberOfNodes();
+            List<String> nodesToBeAddedForWork = new ArrayList<String>();
+            for (int i = 0; i < n; i++) {
+                nodesToBeAddedForWork.add(addedNodes.get(i));
+            }
+            AddNodeWorkResponse response = new AddNodeWorkResponse(w, nodesToBeAddedForWork);
+            pendingWorkResponses.add(response);
+        }
 
     }
 }
diff --git a/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/ClusterEventHandler.java b/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/ClusterWorkExecutor.java
similarity index 91%
rename from asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/ClusterEventHandler.java
rename to asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/ClusterWorkExecutor.java
index 091cf4b..a6c1f8b 100644
--- a/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/ClusterEventHandler.java
+++ b/asterix-app/src/main/java/edu/uci/ics/asterix/hyracks/bootstrap/ClusterWorkExecutor.java
@@ -30,16 +30,17 @@
 import edu.uci.ics.asterix.metadata.cluster.IClusterManagementWorkResponse.Status;
 import edu.uci.ics.asterix.om.util.AsterixClusterProperties;
 
-public class ClusterEventHandler implements Runnable {
+public class ClusterWorkExecutor implements Runnable {
 
-    private static final Logger LOGGER = Logger.getLogger(ClusterEventHandler.class.getName());
+    private static final Logger LOGGER = Logger.getLogger(ClusterWorkExecutor.class.getName());
 
     private final LinkedBlockingQueue<Set<IClusterManagementWork>> inbox;
 
-    public ClusterEventHandler(LinkedBlockingQueue<Set<IClusterManagementWork>> inbox) {
+    public ClusterWorkExecutor(LinkedBlockingQueue<Set<IClusterManagementWork>> inbox) {
         this.inbox = inbox;
     }
-
+    
+   
     @Override
     public void run() {
         while (true) {
@@ -86,11 +87,7 @@
                         }
                     }
                 }
-
-                for (IClusterManagementWork w : nodeAdditionRequests) {
-                    w.getSourceSubscriber().notifyRequestCompletion(
-                            new AddNodeWorkResponse((AddNodeWork) w, Status.SUCCESS, addedNodes));
-                }
+                
 
             } catch (InterruptedException e) {
                 if (LOGGER.isLoggable(Level.SEVERE)) {
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataManager.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataManager.java
index e02cbba..a008c1d 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataManager.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataManager.java
@@ -16,6 +16,7 @@
 package edu.uci.ics.asterix.metadata;
 
 import java.rmi.RemoteException;
+import java.util.Collection;
 import java.util.List;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
@@ -659,4 +660,15 @@
         return FeedPolicy;
     }
 
+    @Override
+    public Collection<FeedActivity> getActiveFeeds(MetadataTransactionContext ctx) throws MetadataException {
+        Collection<FeedActivity> feedActivities = null;
+        try {
+            feedActivities = metadataNode.getActiveFeeds(ctx.getJobId());
+        } catch (RemoteException e) {
+            throw new MetadataException(e);
+        }
+        return feedActivities;
+    }
+
 }
\ No newline at end of file
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataNode.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataNode.java
index 0398777..b180063 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataNode.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataNode.java
@@ -17,8 +17,11 @@
 
 import java.rmi.RemoteException;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import edu.uci.ics.asterix.common.api.IAsterixAppRuntimeContext;
 import edu.uci.ics.asterix.common.config.DatasetConfig.DatasetType;
@@ -37,7 +40,6 @@
 import edu.uci.ics.asterix.metadata.api.IMetadataIndex;
 import edu.uci.ics.asterix.metadata.api.IMetadataNode;
 import edu.uci.ics.asterix.metadata.api.IValueExtractor;
-import edu.uci.ics.asterix.metadata.bootstrap.MetadataConstants;
 import edu.uci.ics.asterix.metadata.bootstrap.MetadataPrimaryIndexes;
 import edu.uci.ics.asterix.metadata.bootstrap.MetadataSecondaryIndexes;
 import edu.uci.ics.asterix.metadata.entities.Dataset;
@@ -1241,4 +1243,34 @@
             throw new MetadataException(e);
         }
     }
+
+    @Override
+    public Collection<FeedActivity> getActiveFeeds(JobId jobId) throws MetadataException, RemoteException {
+        try {
+            ITupleReference searchKey = createTuple();
+            FeedActivityTupleTranslator tupleReaderWriter = new FeedActivityTupleTranslator(true);
+            List<FeedActivity> results = new ArrayList<FeedActivity>();
+            IValueExtractor<FeedActivity> valueExtractor = new MetadataEntityValueExtractor<FeedActivity>(
+                    tupleReaderWriter);
+            searchIndex(jobId, MetadataPrimaryIndexes.FEED_ACTIVITY_DATASET, searchKey, valueExtractor, results);
+            Map<FeedId, FeedActivity> initiatedFeeds = new HashMap<FeedId, FeedActivity>();
+            FeedId fid = null;
+            for (FeedActivity fa : results) {
+                switch (fa.getActivityType()) {
+                    case FEED_BEGIN:
+                        fid = new FeedId(fa.getDataverseName(), fa.getDatasetName());
+                        initiatedFeeds.put(fid, fa);
+                        break;
+                    case FEED_FAILURE:
+                    case FEED_END:
+                        fid = new FeedId(fa.getDataverseName(), fa.getDatasetName());
+                        initiatedFeeds.remove(fid);
+                        break;
+                }
+            }
+            return initiatedFeeds.values();
+        } catch (Exception e) {
+            throw new MetadataException(e);
+        }
+    }
 }
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IClusterEventsSubscriber.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IClusterEventsSubscriber.java
index 39f9927..049a45c 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IClusterEventsSubscriber.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IClusterEventsSubscriber.java
@@ -17,6 +17,7 @@
 import java.util.Set;
 
 import edu.uci.ics.asterix.metadata.cluster.IClusterManagementWorkResponse;
+import edu.uci.ics.asterix.om.util.AsterixClusterProperties.State;
 
 public interface IClusterEventsSubscriber {
 
@@ -32,6 +33,15 @@
      */
     public Set<IClusterManagementWork> notifyNodeJoin(String joinedNodeId);
 
+    /**
+     * @param response
+     */
     public void notifyRequestCompletion(IClusterManagementWorkResponse response);
 
+    /**
+     * @param previousState
+     * @param newState
+     */
+    public void notifyStateChange(State previousState, State newState);
+
 }
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IMetadataManager.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IMetadataManager.java
index 5f1acf8..a7833d2 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IMetadataManager.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IMetadataManager.java
@@ -16,6 +16,7 @@
 package edu.uci.ics.asterix.metadata.api;
 
 import java.rmi.RemoteException;
+import java.util.Collection;
 import java.util.List;
 
 import edu.uci.ics.asterix.common.exceptions.ACIDException;
@@ -469,9 +470,23 @@
      */
     public void addFeedPolicy(MetadataTransactionContext ctx, FeedPolicy policy) throws MetadataException;
 
+    /**
+     * @param ctx
+     * @param dataverse
+     * @param policyName
+     * @return
+     * @throws MetadataException
+     */
     public FeedPolicy getFeedPolicy(MetadataTransactionContext ctx, String dataverse, String policyName)
             throws MetadataException;
 
+    /**
+     * @param ctx
+     * @return
+     * @throws MetadataException
+     */
+    public Collection<FeedActivity> getActiveFeeds(MetadataTransactionContext ctx) throws MetadataException;
+
     public void initializeDatasetIdFactory(MetadataTransactionContext ctx) throws MetadataException;
 
     public int getMostRecentDatasetId() throws MetadataException;
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IMetadataNode.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IMetadataNode.java
index cf5f41e..9ab483dc 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IMetadataNode.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/api/IMetadataNode.java
@@ -18,6 +18,7 @@
 import java.io.Serializable;
 import java.rmi.Remote;
 import java.rmi.RemoteException;
+import java.util.Collection;
 import java.util.List;
 
 import edu.uci.ics.asterix.common.exceptions.ACIDException;
@@ -524,4 +525,11 @@
     public FeedPolicy getFeedPolicy(JobId jobId, String dataverse, String policy) throws MetadataException,
             RemoteException;
 
+    /**
+     * @param jobId
+     * @return
+     * @throws MetadataException
+     * @throws RemoteException
+     */
+    public Collection<FeedActivity> getActiveFeeds(JobId jobId) throws MetadataException, RemoteException;
 }
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/AddNodeWorkResponse.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/AddNodeWorkResponse.java
index fca9990..40999f0 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/AddNodeWorkResponse.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/AddNodeWorkResponse.java
@@ -14,21 +14,28 @@
  */
 package edu.uci.ics.asterix.metadata.cluster;
 
-import java.util.Set;
-
-import edu.uci.ics.asterix.event.schema.cluster.Node;
+import java.util.ArrayList;
+import java.util.List;
 
 public class AddNodeWorkResponse extends ClusterManagementWorkResponse {
 
-    private final Set<Node> nodesAdded;
+    private final List<String> nodesToBeAdded;
+    private final List<String> nodesAdded;
 
-    public AddNodeWorkResponse(AddNodeWork w, Status status, Set<Node> nodesAdded) {
-        super(w, status);
-        this.nodesAdded = nodesAdded;
+    public AddNodeWorkResponse(AddNodeWork w, List<String> nodesToBeAdded) {
+        super(w);
+        this.nodesToBeAdded = nodesToBeAdded;
+        this.nodesAdded = new ArrayList<String>();
     }
 
-    public Set<Node> getNodesAdded() {
+    public List<String> getNodesAdded() {
         return nodesAdded;
     }
 
+    public boolean updateProgress(String addedNode) {
+        nodesToBeAdded.remove(addedNode);
+        nodesAdded.add(addedNode);
+        return nodesToBeAdded.isEmpty();
+    }
+
 }
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/ClusterManagementWorkResponse.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/ClusterManagementWorkResponse.java
index 5970978..d578a77 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/ClusterManagementWorkResponse.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/ClusterManagementWorkResponse.java
@@ -6,11 +6,11 @@
 
     protected final IClusterManagementWork work;
 
-    protected final Status status;
+    protected Status status;
 
-    public ClusterManagementWorkResponse(IClusterManagementWork w, Status status) {
+    public ClusterManagementWorkResponse(IClusterManagementWork w) {
         this.work = w;
-        this.status = status;
+        this.status = Status.IN_PROGRESS;
     }
 
     @Override
@@ -23,4 +23,9 @@
         return status;
     }
 
+    @Override
+    public void setStatus(Status status) {
+        this.status = status;
+    }
+
 }
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/IClusterManagementWorkResponse.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/IClusterManagementWorkResponse.java
index 1ac9e34..dfc88ac 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/IClusterManagementWorkResponse.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/IClusterManagementWorkResponse.java
@@ -5,6 +5,7 @@
 public interface IClusterManagementWorkResponse {
 
     public enum Status {
+        IN_PROGRESS,
         SUCCESS,
         FAILURE
     }
@@ -19,4 +20,9 @@
      */
     public Status getStatus();
 
+    /**
+     * @param status
+     */
+    public void setStatus(Status status);
+
 }
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/RemoveNodeWorkResponse.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/RemoveNodeWorkResponse.java
index 48445ef..58ea05e 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/RemoveNodeWorkResponse.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/cluster/RemoveNodeWorkResponse.java
@@ -14,19 +14,21 @@
  */
 package edu.uci.ics.asterix.metadata.cluster;
 
+import java.util.HashSet;
 import java.util.Set;
 
 public class RemoveNodeWorkResponse extends ClusterManagementWorkResponse {
 
-    private final Set<String> nodesRemoved;
+    private Set<String> nodesToBeRemoved = new HashSet<String>();
 
-    public RemoveNodeWorkResponse(AddNodeWork w, Status status, Set<String> nodesRemoved) {
-        super(w, status);
-        this.nodesRemoved = nodesRemoved;
+    public RemoveNodeWorkResponse(RemoveNodeWork w, Status status) {
+        super(w);
+        nodesToBeRemoved.addAll(w.getNodesToBeRemoved());
     }
 
-    public Set<String> getNodesAdded() {
-        return nodesRemoved;
-    }
+    public boolean updateProgress(Set<String> failedNodeIds) {
+        nodesToBeRemoved.removeAll(failedNodeIds);
+        return nodesToBeRemoved.isEmpty();
 
+    }
 }
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/feeds/FeedLifecycleListener.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/feeds/FeedLifecycleListener.java
index 257c8fd..c436fde 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/feeds/FeedLifecycleListener.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/feeds/FeedLifecycleListener.java
@@ -24,40 +24,30 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.Random;
 import java.util.Set;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import edu.uci.ics.asterix.common.exceptions.ACIDException;
-import edu.uci.ics.asterix.event.schema.cluster.Node;
 import edu.uci.ics.asterix.metadata.MetadataException;
 import edu.uci.ics.asterix.metadata.MetadataManager;
 import edu.uci.ics.asterix.metadata.MetadataTransactionContext;
 import edu.uci.ics.asterix.metadata.api.IClusterEventsSubscriber;
 import edu.uci.ics.asterix.metadata.api.IClusterManagementWork;
 import edu.uci.ics.asterix.metadata.cluster.AddNodeWork;
-import edu.uci.ics.asterix.metadata.cluster.AddNodeWorkResponse;
 import edu.uci.ics.asterix.metadata.cluster.ClusterManager;
 import edu.uci.ics.asterix.metadata.cluster.IClusterManagementWorkResponse;
 import edu.uci.ics.asterix.metadata.entities.FeedActivity;
 import edu.uci.ics.asterix.metadata.entities.FeedActivity.FeedActivityType;
 import edu.uci.ics.asterix.metadata.feeds.FeedLifecycleListener.FeedFailure.FailureType;
 import edu.uci.ics.asterix.om.util.AsterixAppContextInfo;
-import edu.uci.ics.asterix.om.util.AsterixClusterProperties;
+import edu.uci.ics.asterix.om.util.AsterixClusterProperties.State;
 import edu.uci.ics.hyracks.algebricks.runtime.base.IPushRuntimeFactory;
 import edu.uci.ics.hyracks.algebricks.runtime.operators.meta.AlgebricksMetaOperatorDescriptor;
 import edu.uci.ics.hyracks.algebricks.runtime.operators.std.AssignRuntimeFactory;
 import edu.uci.ics.hyracks.algebricks.runtime.operators.std.EmptyTupleSourceRuntimeFactory;
 import edu.uci.ics.hyracks.api.client.IHyracksClientConnection;
-import edu.uci.ics.hyracks.api.constraints.Constraint;
-import edu.uci.ics.hyracks.api.constraints.PartitionConstraintHelper;
-import edu.uci.ics.hyracks.api.constraints.expressions.ConstantExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.ConstraintExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.LValueConstraintExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.PartitionCountExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.PartitionLocationExpression;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
@@ -79,21 +69,21 @@
     public static FeedLifecycleListener INSTANCE = new FeedLifecycleListener();
 
     private LinkedBlockingQueue<Message> jobEventInbox;
-    private LinkedBlockingQueue<FeedFailureReport> failureEventInbox;
-    private Map<Integer, FeedFailureReport> feedsWaitingForResponse = new HashMap<Integer, FeedFailureReport>();
+    private LinkedBlockingQueue<IClusterManagementWorkResponse> responseInbox;
 
     private FeedLifecycleListener() {
         jobEventInbox = new LinkedBlockingQueue<Message>();
         feedJobNotificationHandler = new FeedJobNotificationHandler(jobEventInbox);
-        failureEventInbox = new LinkedBlockingQueue<FeedFailureReport>();
-        feedFailureNotificationHandler = new FeedFailureHandler(failureEventInbox);
+        responseInbox = new LinkedBlockingQueue<IClusterManagementWorkResponse>();
+        feedWorkRequestResponseHandler = new FeedWorkRequestResponseHandler(responseInbox);
+
         new Thread(feedJobNotificationHandler).start();
-        new Thread(feedFailureNotificationHandler).start();
+        new Thread(feedWorkRequestResponseHandler).start();
         ClusterManager.INSTANCE.registerSubscriber(this);
     }
 
     private final FeedJobNotificationHandler feedJobNotificationHandler;
-    private final FeedFailureHandler feedFailureNotificationHandler;
+    private final FeedWorkRequestResponseHandler feedWorkRequestResponseHandler;
 
     @Override
     public void notifyJobStart(JobId jobId) throws HyracksException {
@@ -392,7 +382,7 @@
 
         AddNodeWork addNodesWork = new AddNodeWork(failureMap.keySet().size(), this);
         work.add(addNodesWork);
-        feedsWaitingForResponse.put(addNodesWork.getWorkId(), failureReport);
+        feedWorkRequestResponseHandler.registerFeedWork(addNodesWork.getWorkId(), failureReport);
         return work;
     }
 
@@ -421,133 +411,35 @@
 
     @Override
     public void notifyRequestCompletion(IClusterManagementWorkResponse response) {
-        IClusterManagementWork submittedWork = response.getWork();
-        switch (submittedWork.getClusterManagementWorkType()) {
-            case ADD_NODE:
-                AddNodeWorkResponse resp = (AddNodeWorkResponse) response;
-                switch (resp.getStatus()) {
-                    case FAILURE:
-                        break;
-                    case SUCCESS:
-                        AddNodeWork work = (AddNodeWork) submittedWork;
-                        FeedFailureReport failureReport = feedsWaitingForResponse.remove(work.getWorkId());
-                        Set<FeedInfo> affectedFeeds = failureReport.failures.keySet();
-                        for (FeedInfo feedInfo : affectedFeeds) {
-                            try {
-                                recoverFeed(feedInfo, resp, failureReport.failures.get(feedInfo));
-                                if (LOGGER.isLoggable(Level.INFO)) {
-                                    LOGGER.info("Recovered feed:" + feedInfo);
-                                }
-                            } catch (Exception e) {
-                                if (LOGGER.isLoggable(Level.SEVERE)) {
-                                    LOGGER.severe("Unable to recover feed:" + feedInfo);
-                                }
-                            }
-                        }
-                        break;
-                }
-                resp.getNodesAdded();
-                break;
-            case REMOVE_NODE:
-                break;
+        try {
+            responseInbox.put(response);
+        } catch (InterruptedException e) {
+            if (LOGGER.isLoggable(Level.WARNING)) {
+                LOGGER.warning("Interrupted exception");
+            }
         }
     }
 
-    private void recoverFeed(FeedInfo feedInfo, AddNodeWorkResponse resp, List<FeedFailure> feedFailures)
-            throws Exception {
-        for (FeedFailure feedFailure : feedFailures) {
-            switch (feedFailure.failureType) {
-                case INGESTION_NODE:
-                    alterFeedJobSpec(feedInfo, resp, feedFailure.nodeId);
-                    break;
-            }
-        }
-        JobSpecification spec = feedInfo.jobSpec;
-        AsterixAppContextInfo.getInstance().getHcc().startJob(feedInfo.jobSpec);
+    @Override
+    public void notifyStateChange(State previousState, State newState) {
+       switch(newState){
+           case ACTIVE:
+                 if(previousState.equals((State.UNUSABLE)){
+                     resumeActiveFeeds();
+                 }
+                 break;
+       }
+        
     }
 
-    private void alterFeedJobSpec(FeedInfo feedInfo, AddNodeWorkResponse resp, String failedNodeId) {
-        Random r = new Random();
-        Object[] rnodes = resp.getNodesAdded().toArray();
-        Node replacementNode = (Node) rnodes[r.nextInt(rnodes.length)];
-        String replacementNodeId = AsterixClusterProperties.INSTANCE.getCluster().getInstanceName() + "_"
-                + replacementNode.getId();
-        Map<OperatorDescriptorId, IOperatorDescriptor> opMap = feedInfo.jobSpec.getOperatorMap();
-        Set<Constraint> userConstraints = feedInfo.jobSpec.getUserConstraints();
-        List<Constraint> locationConstraintsToReplace = new ArrayList<Constraint>();
-        List<Constraint> countConstraintsToReplace = new ArrayList<Constraint>();
-        List<OperatorDescriptorId> modifiedOperators = new ArrayList<OperatorDescriptorId>();
-        Map<OperatorDescriptorId, List<Constraint>> candidateConstraints = new HashMap<OperatorDescriptorId, List<Constraint>>();
-        Map<OperatorDescriptorId, List<String>> newConstraints = new HashMap<OperatorDescriptorId, List<String>>();
-        OperatorDescriptorId opId = null;
-        for (Constraint constraint : userConstraints) {
-            LValueConstraintExpression lexpr = constraint.getLValue();
-            ConstraintExpression cexpr = constraint.getRValue();
-            switch (lexpr.getTag()) {
-                case PARTITION_COUNT:
-                    opId = ((PartitionCountExpression) lexpr).getOperatorDescriptorId();
-                    if (modifiedOperators.contains(opId)) {
-                        countConstraintsToReplace.add(constraint);
-                    } else {
-                        List<Constraint> clist = candidateConstraints.get(opId);
-                        if (clist == null) {
-                            clist = new ArrayList<Constraint>();
-                            candidateConstraints.put(opId, clist);
-                        }
-                        clist.add(constraint);
-                    }
-                    break;
-                case PARTITION_LOCATION:
-                    opId = ((PartitionLocationExpression) lexpr).getOperatorDescriptorId();
-                    String oldLocation = (String) ((ConstantExpression) cexpr).getValue();
-                    if (oldLocation.equals(failedNodeId)) {
-                        locationConstraintsToReplace.add(constraint);
-                        modifiedOperators.add(((PartitionLocationExpression) lexpr).getOperatorDescriptorId());
-                        List<String> newLocs = newConstraints.get(opId);
-                        if (newLocs == null) {
-                            newLocs = new ArrayList<String>();
-                            newConstraints.put(opId, newLocs);
-                        }
-                        newLocs.add(replacementNodeId);
-                    } else {
-                        if (modifiedOperators.contains(opId)) {
-                            locationConstraintsToReplace.add(constraint);
-                            List<String> newLocs = newConstraints.get(opId);
-                            if (newLocs == null) {
-                                newLocs = new ArrayList<String>();
-                                newConstraints.put(opId, newLocs);
-                            }
-                            newLocs.add(oldLocation);
-                        } else {
-                            List<Constraint> clist = candidateConstraints.get(opId);
-                            if (clist == null) {
-                                clist = new ArrayList<Constraint>();
-                                candidateConstraints.put(opId, clist);
-                            }
-                            clist.add(constraint);
-                        }
-                    }
-                    break;
-            }
+    private void resumeActiveFeeds() {
+        MetadataTransactionContext ctx = null;
+        try {
+            ctx = MetadataManager.INSTANCE.beginTransaction();
+            MetadataManager.INSTANCE.getActiveFeeds(ctx);
+        } catch (Exception e) {
+
         }
-
-        feedInfo.jobSpec.getUserConstraints().removeAll(locationConstraintsToReplace);
-        feedInfo.jobSpec.getUserConstraints().removeAll(countConstraintsToReplace);
-
-        for (OperatorDescriptorId mopId : modifiedOperators) {
-            List<Constraint> clist = candidateConstraints.get(mopId);
-            if (clist != null && !clist.isEmpty()) {
-                feedInfo.jobSpec.getUserConstraints().removeAll(clist);
-            }
-        }
-
-        for (Entry<OperatorDescriptorId, List<String>> entry : newConstraints.entrySet()) {
-            OperatorDescriptorId nopId = entry.getKey();
-            List<String> clist = entry.getValue();
-            IOperatorDescriptor op = feedInfo.jobSpec.getOperatorMap().get(nopId);
-            PartitionConstraintHelper.addAbsoluteLocationConstraint(feedInfo.jobSpec, op,
-                    clist.toArray(new String[] {}));
-        }
-
     }
+
 }
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/feeds/FeedWorkRequestResponseHandler.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/feeds/FeedWorkRequestResponseHandler.java
new file mode 100644
index 0000000..8f9beb7
--- /dev/null
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/feeds/FeedWorkRequestResponseHandler.java
@@ -0,0 +1,188 @@
+package edu.uci.ics.asterix.metadata.feeds;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+import java.util.Set;
+import java.util.Map.Entry;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import edu.uci.ics.asterix.metadata.api.IClusterManagementWork;
+import edu.uci.ics.asterix.metadata.cluster.AddNodeWork;
+import edu.uci.ics.asterix.metadata.cluster.AddNodeWorkResponse;
+import edu.uci.ics.asterix.metadata.cluster.IClusterManagementWorkResponse;
+import edu.uci.ics.asterix.metadata.feeds.FeedLifecycleListener.FeedFailure;
+import edu.uci.ics.asterix.metadata.feeds.FeedLifecycleListener.FeedFailureReport;
+import edu.uci.ics.asterix.metadata.feeds.FeedLifecycleListener.FeedInfo;
+import edu.uci.ics.asterix.om.util.AsterixAppContextInfo;
+import edu.uci.ics.hyracks.api.constraints.Constraint;
+import edu.uci.ics.hyracks.api.constraints.PartitionConstraintHelper;
+import edu.uci.ics.hyracks.api.constraints.expressions.ConstantExpression;
+import edu.uci.ics.hyracks.api.constraints.expressions.ConstraintExpression;
+import edu.uci.ics.hyracks.api.constraints.expressions.LValueConstraintExpression;
+import edu.uci.ics.hyracks.api.constraints.expressions.PartitionCountExpression;
+import edu.uci.ics.hyracks.api.constraints.expressions.PartitionLocationExpression;
+import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
+import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
+import edu.uci.ics.hyracks.api.job.JobSpecification;
+
+public class FeedWorkRequestResponseHandler implements Runnable {
+
+    private static final Logger LOGGER = Logger.getLogger(FeedWorkRequestResponseHandler.class.getName());
+
+    private final LinkedBlockingQueue<IClusterManagementWorkResponse> inbox;
+
+    private Map<Integer, FeedFailureReport> feedsWaitingForResponse = new HashMap<Integer, FeedFailureReport>();
+
+    public FeedWorkRequestResponseHandler(LinkedBlockingQueue<IClusterManagementWorkResponse> inbox) {
+        this.inbox = inbox;
+    }
+
+    @Override
+    public void run() {
+        while (true) {
+            IClusterManagementWorkResponse response = null;
+            try {
+                response = inbox.take();
+            } catch (InterruptedException e) {
+                if (LOGGER.isLoggable(Level.WARNING)) {
+                    LOGGER.warning("Interrupted exception " + e.getMessage());
+                }
+            }
+            IClusterManagementWork submittedWork = response.getWork();
+            switch (submittedWork.getClusterManagementWorkType()) {
+                case ADD_NODE:
+                    AddNodeWorkResponse resp = (AddNodeWorkResponse) response;
+                    switch (resp.getStatus()) {
+                        case FAILURE:
+                            break;
+                        case SUCCESS:
+                            AddNodeWork work = (AddNodeWork) submittedWork;
+                            FeedFailureReport failureReport = feedsWaitingForResponse.remove(work.getWorkId());
+                            Set<FeedInfo> affectedFeeds = failureReport.failures.keySet();
+                            for (FeedInfo feedInfo : affectedFeeds) {
+                                try {
+                                    recoverFeed(feedInfo, resp, failureReport.failures.get(feedInfo));
+                                    if (LOGGER.isLoggable(Level.INFO)) {
+                                        LOGGER.info("Recovered feed:" + feedInfo);
+                                    }
+                                } catch (Exception e) {
+                                    if (LOGGER.isLoggable(Level.SEVERE)) {
+                                        LOGGER.severe("Unable to recover feed:" + feedInfo);
+                                    }
+                                }
+                            }
+                            break;
+                    }
+                    resp.getNodesAdded();
+                    break;
+                case REMOVE_NODE:
+                    break;
+            }
+        }
+    }
+
+    private void recoverFeed(FeedInfo feedInfo, AddNodeWorkResponse resp, List<FeedFailure> feedFailures)
+            throws Exception {
+        for (FeedFailure feedFailure : feedFailures) {
+            switch (feedFailure.failureType) {
+                case INGESTION_NODE:
+                    alterFeedJobSpec(feedInfo, resp, feedFailure.nodeId);
+                    break;
+            }
+        }
+        JobSpecification spec = feedInfo.jobSpec;
+        //AsterixAppContextInfo.getInstance().getHcc().startJob(feedInfo.jobSpec);
+    }
+
+    private void alterFeedJobSpec(FeedInfo feedInfo, AddNodeWorkResponse resp, String failedNodeId) {
+        Random r = new Random();
+        String[] rnodes = resp.getNodesAdded().toArray(new String[] {});
+        String replacementNode = rnodes[r.nextInt(rnodes.length)];
+        Map<OperatorDescriptorId, IOperatorDescriptor> opMap = feedInfo.jobSpec.getOperatorMap();
+        Set<Constraint> userConstraints = feedInfo.jobSpec.getUserConstraints();
+        List<Constraint> locationConstraintsToReplace = new ArrayList<Constraint>();
+        List<Constraint> countConstraintsToReplace = new ArrayList<Constraint>();
+        List<OperatorDescriptorId> modifiedOperators = new ArrayList<OperatorDescriptorId>();
+        Map<OperatorDescriptorId, List<Constraint>> candidateConstraints = new HashMap<OperatorDescriptorId, List<Constraint>>();
+        Map<OperatorDescriptorId, List<String>> newConstraints = new HashMap<OperatorDescriptorId, List<String>>();
+        OperatorDescriptorId opId = null;
+        for (Constraint constraint : userConstraints) {
+            LValueConstraintExpression lexpr = constraint.getLValue();
+            ConstraintExpression cexpr = constraint.getRValue();
+            switch (lexpr.getTag()) {
+                case PARTITION_COUNT:
+                    opId = ((PartitionCountExpression) lexpr).getOperatorDescriptorId();
+                    if (modifiedOperators.contains(opId)) {
+                        countConstraintsToReplace.add(constraint);
+                    } else {
+                        List<Constraint> clist = candidateConstraints.get(opId);
+                        if (clist == null) {
+                            clist = new ArrayList<Constraint>();
+                            candidateConstraints.put(opId, clist);
+                        }
+                        clist.add(constraint);
+                    }
+                    break;
+                case PARTITION_LOCATION:
+                    opId = ((PartitionLocationExpression) lexpr).getOperatorDescriptorId();
+                    String oldLocation = (String) ((ConstantExpression) cexpr).getValue();
+                    if (oldLocation.equals(failedNodeId)) {
+                        locationConstraintsToReplace.add(constraint);
+                        modifiedOperators.add(((PartitionLocationExpression) lexpr).getOperatorDescriptorId());
+                        List<String> newLocs = newConstraints.get(opId);
+                        if (newLocs == null) {
+                            newLocs = new ArrayList<String>();
+                            newConstraints.put(opId, newLocs);
+                        }
+                        newLocs.add(replacementNode);
+                    } else {
+                        if (modifiedOperators.contains(opId)) {
+                            locationConstraintsToReplace.add(constraint);
+                            List<String> newLocs = newConstraints.get(opId);
+                            if (newLocs == null) {
+                                newLocs = new ArrayList<String>();
+                                newConstraints.put(opId, newLocs);
+                            }
+                            newLocs.add(oldLocation);
+                        } else {
+                            List<Constraint> clist = candidateConstraints.get(opId);
+                            if (clist == null) {
+                                clist = new ArrayList<Constraint>();
+                                candidateConstraints.put(opId, clist);
+                            }
+                            clist.add(constraint);
+                        }
+                    }
+                    break;
+            }
+        }
+
+        feedInfo.jobSpec.getUserConstraints().removeAll(locationConstraintsToReplace);
+        feedInfo.jobSpec.getUserConstraints().removeAll(countConstraintsToReplace);
+
+        for (OperatorDescriptorId mopId : modifiedOperators) {
+            List<Constraint> clist = candidateConstraints.get(mopId);
+            if (clist != null && !clist.isEmpty()) {
+                feedInfo.jobSpec.getUserConstraints().removeAll(clist);
+            }
+        }
+
+        for (Entry<OperatorDescriptorId, List<String>> entry : newConstraints.entrySet()) {
+            OperatorDescriptorId nopId = entry.getKey();
+            List<String> clist = entry.getValue();
+            IOperatorDescriptor op = feedInfo.jobSpec.getOperatorMap().get(nopId);
+            PartitionConstraintHelper.addAbsoluteLocationConstraint(feedInfo.jobSpec, op,
+                    clist.toArray(new String[] {}));
+        }
+
+    }
+
+    public void registerFeedWork(int workId, FeedFailureReport failureReport) {
+        feedsWaitingForResponse.put(workId, failureReport);
+    }
+}
diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/om/util/AsterixClusterProperties.java b/asterix-om/src/main/java/edu/uci/ics/asterix/om/util/AsterixClusterProperties.java
index 29e3b3b..f764954 100644
--- a/asterix-om/src/main/java/edu/uci/ics/asterix/om/util/AsterixClusterProperties.java
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/om/util/AsterixClusterProperties.java
@@ -69,7 +69,7 @@
     private State state = State.UNUSABLE;
 
     public void removeNCConfiguration(String nodeId) {
-        state = State.UNUSABLE;
+        // state = State.UNUSABLE;
         ncConfiguration.remove(nodeId);
     }
 
@@ -115,7 +115,7 @@
 
     public Node getAvailableSubstitutionNode() {
         List<Node> subNodes = cluster.getSubstituteNodes().getNode();
-        return subNodes.isEmpty() ? null : subNodes.remove(0);
+        return subNodes.isEmpty() ? null : subNodes.get(0);
     }
 
 }