Merge remote branch 'upstream/master'

18 files changed, 1127 insertions, 452 deletions

diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/AbstractResource.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/AbstractResource.java
index ee65add0..feef8b3e 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/AbstractResource.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/AbstractResource.java
@@ -65,21 +65,32 @@ public class AbstractResource {
 	 * Creates a response with HTTP status code of 202 (accepted), also setting the location header to given location.
 	 * This is typically done while triggering long running tasks
 	 * 
-	 * @param uriElements
-	 *            URI Elements to be appended to the base URI
+	 * @param locationURI
+	 *            URI to be appended to the base URI
 	 * @return the {@link Response} object
 	 */
-	protected Response acceptedResponse(Object...uriElements) {
-		return Response.status(Status.ACCEPTED).location(createAbsoluteURI(uriElements)).build();
+	protected Response acceptedResponse(String locationURI) {
+		return Response.status(Status.ACCEPTED).location(createAbsoluteURI(locationURI)).build();
+	}
+
+	/**
+	 * Creates a response with HTTP status code of 404 (not found), also setting the given message in the response body
+	 * 
+	 * @param message
+	 *            Message to be set in the response body
+	 * @return the {@link Response} object
+	 */
+	protected Response notFoundResponse(String message) {
+		return Response.status(Status.NOT_FOUND).type(MediaType.TEXT_HTML).entity(message).build();
 	}
 
 	/**
 	 * Creates a new URI that is relative to the <b>base URI</b> of the application
-	 * @param uriElements URI Elements to be appended to the base URI
+	 * @param uriString URI String to be appended to the base URI
 	 * @return newly created URI
 	 */
-	private URI createAbsoluteURI(Object[] uriElements) {
-		return uriInfo.getBaseUriBuilder().build(uriElements);
+	private URI createAbsoluteURI(String uriString) {
+		return uriInfo.getBaseUriBuilder().path(uriString).build();
 	}
 
 	/**
@@ -123,6 +134,15 @@ public class AbstractResource {
 	protected Response badRequestResponse(String errMessage) {
 		return Response.status(Status.BAD_REQUEST).type(MediaType.TEXT_HTML).entity(errMessage).build();
 	}
+	
+	/**
+	 * Creates a response with HTTP status code of 401 (unauthorized)
+	 * 
+	 * @return the {@link Response} object
+	 */
+	protected Response unauthorizedResponse() {
+		return Response.status(Status.UNAUTHORIZED).build();
+	}
 
 	/**
 	 * Creates an OK response and sets the entity in the response body.
@@ -138,6 +158,17 @@ public class AbstractResource {
 	}
 
 	/**
+	 * Creates an OK response without any entity in the response body.
+	 * 
+	 * @param mediaType
+	 *            Media type to be set on the response
+	 * @return the {@link Response} object
+	 */
+	protected Response okResponse(String mediaType) {
+		return Response.ok().type(mediaType).build();
+	}
+
+	/**
 	 * Creates a streaming output response and sets the given streaming output in the response. Typically used for
 	 * "download" requests
 	 * 
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/AbstractServersResource.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/AbstractServersResource.java
index 0bc0f061..dd6e2804 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/AbstractServersResource.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/AbstractServersResource.java
@@ -20,9 +20,6 @@
  */
 package com.gluster.storage.management.server.resources;
 
-import com.gluster.storage.management.core.exceptions.GlusterRuntimeException;
-import com.gluster.storage.management.core.model.Server;
-import com.gluster.storage.management.core.model.Status;
 import com.gluster.storage.management.server.utils.GlusterUtil;
 import com.gluster.storage.management.server.utils.ServerUtil;
 import com.sun.jersey.api.core.InjectParam;
@@ -37,19 +34,5 @@ public class AbstractServersResource extends AbstractResource {
 	@InjectParam
 	protected GlusterUtil glusterUtil;
 
-	/**
-	 * Fetch details of the given server. The server name must be populated in the object before calling this method.
-	 * 
-	 * @param server
-	 *            Server whose details are to be fetched
-	 */
-	protected void fetchServerDetails(Server server) {
-		// fetch standard server details like cpu, disk, memory details
-		Object response = serverUtil.executeOnServer(true, server.getName(), "get_server_details.py --only-data-disks", Server.class);
-		if (response instanceof Status) {
-			// TODO: check if this happened because the server is not reachable, and if yes, set it's status as offline
-			throw new GlusterRuntimeException(((Status)response).getMessage());
-		}
-		server.copyFrom((Server) response); // Update the details in <Server> object
-	}
+	// TODO: Remove this class!
 }
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/ClustersResource.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/ClustersResource.java
index 2ce23a4e..4c834973 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/ClustersResource.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/ClustersResource.java
@@ -106,7 +106,6 @@ public class ClustersResource extends AbstractResource {
 			return badRequestResponse("Server [" + knownServer + "] is already present in cluster ["
 					+ mappedCluster.getName() + "]!");
 		}
-
 		
 		try {
 			clusterService.registerCluster(clusterName, knownServer);
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/DiscoveredServersResource.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/DiscoveredServersResource.java
index aba88d82..283ab147 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/DiscoveredServersResource.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/DiscoveredServersResource.java
@@ -18,6 +18,8 @@
  *******************************************************************************/
 package com.gluster.storage.management.server.resources;
 
+import static com.gluster.storage.management.core.constants.RESTConstants.PATH_PARAM_SERVER_NAME;
+import static com.gluster.storage.management.core.constants.RESTConstants.QUERY_PARAM_DETAILS;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_PATH_DISCOVERED_SERVERS;
 
 import java.util.ArrayList;
@@ -29,16 +31,13 @@ import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
 import javax.ws.rs.QueryParam;
 import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
 
 import org.springframework.stereotype.Component;
 
-import com.gluster.storage.management.core.constants.CoreConstants;
-import com.gluster.storage.management.core.model.Response;
 import com.gluster.storage.management.core.model.Server;
-import com.gluster.storage.management.core.model.Status;
-import com.gluster.storage.management.core.response.GenericResponse;
 import com.gluster.storage.management.core.response.ServerListResponse;
-import com.gluster.storage.management.core.response.StringListResponse;
+import com.gluster.storage.management.core.response.ServerNameListResponse;
 import com.sun.jersey.spi.resource.Singleton;
 
 @Component
@@ -67,57 +66,76 @@ public class DiscoveredServersResource extends AbstractServersResource {
 
 	@GET
 	@Produces(MediaType.APPLICATION_XML)
-	@SuppressWarnings("rawtypes")
-	public Response getDiscoveredServers(@QueryParam("details") Boolean getDetails) {
-		if(getDetails != null && getDetails == true) {
-			return getDiscoveredServerDetails();
+	public Response getDiscoveredServersXML(@QueryParam(QUERY_PARAM_DETAILS) Boolean details) {
+		return getDiscoveredServersResponse(details, MediaType.APPLICATION_XML);
+	}
+
+	@GET
+	@Produces(MediaType.APPLICATION_JSON)
+	public Response getDiscoveredServersJSON(@QueryParam(QUERY_PARAM_DETAILS) Boolean details) {
+		return getDiscoveredServersResponse(details, MediaType.APPLICATION_JSON);
+	}
+
+	private Response getDiscoveredServersResponse(Boolean details, String mediaType) {
+		if(details != null && details == true) {
+			try {
+				List<Server> discoveredServers = getDiscoveredServerDetails();
+				return okResponse(new ServerListResponse(discoveredServers), mediaType);
+			} catch(Exception e) {
+				return errorResponse(e.getMessage());
+			}
+		} else {		
+			return okResponse(new ServerNameListResponse(getDiscoveredServerNames()), mediaType);
 		}
-		return new StringListResponse(getDiscoveredServerNames());
 	}
 
-	private ServerListResponse getDiscoveredServerDetails() {
+	private List<Server> getDiscoveredServerDetails() {
 		List<Server> discoveredServers = new ArrayList<Server>();
-		List<String> serverNames = getDiscoveredServerNames();
-		GenericResponse<Server> discoveredServerResponse;
-		int errCount = 0;
-		StringBuilder errMsg = new StringBuilder("Couldn't fetch details for server(s): ");
-		for (String serverName : serverNames) {
-			discoveredServerResponse = getDiscoveredServer(serverName);
-			if (!discoveredServerResponse.getStatus().isSuccess()) {
-				errMsg.append(CoreConstants.NEWLINE + serverName + " : " + discoveredServerResponse.getStatus());
-				errCount++;
-			} else {
-				discoveredServers.add(discoveredServerResponse.getData());
+		for (String serverName : getDiscoveredServerNames()) {
+			try {
+				discoveredServers.add(getDiscoveredServer(serverName));
+			} catch(Exception e) {
+				// TODO: Log the exception 
+				// continue with next discovered server
 			}
 		}
-		Status status = null;
-		if(errCount == 0) {
-			status = new Status(Status.STATUS_CODE_SUCCESS, "Success");
-		} else if(errCount == serverNames.size()) {
-			status = new Status(Status.STATUS_CODE_FAILURE, errMsg.toString());
-		} else {
-			status = new Status(Status.STATUS_CODE_PART_SUCCESS, errMsg.toString());
-		}
-		return new ServerListResponse(status, discoveredServers);
+		return discoveredServers;
 	}
 	
-	@Path("/{serverName}")
+	@Path("{" + PATH_PARAM_SERVER_NAME + "}")
 	@GET
 	@Produces(MediaType.APPLICATION_XML)
-	public GenericResponse<Server> getDiscoveredServer(@PathParam("serverName") String serverName) {
-		Server server = new Server(serverName);
+	public Response getDiscoveredServerXML(@PathParam(PATH_PARAM_SERVER_NAME) String serverName) {
+		return getDiscoveredServerResponse(serverName, MediaType.APPLICATION_XML);
+	}
+
+	@Path("{" + PATH_PARAM_SERVER_NAME + "}")
+	@GET
+	@Produces(MediaType.APPLICATION_JSON)
+	public Response getDiscoveredServerJSON(@PathParam(PATH_PARAM_SERVER_NAME) String serverName) {
+		return getDiscoveredServerResponse(serverName, MediaType.APPLICATION_JSON);
+	}
+
+	private Response getDiscoveredServerResponse(String serverName, String mediaType) {
+		if(serverName == null || serverName.isEmpty()) {
+			return badRequestResponse("Server name must not be empty!");
+		}
 		try {
-			fetchServerDetails(server);
+			return okResponse(getDiscoveredServer(serverName), mediaType);
 		} catch (Exception e) {
-			return new GenericResponse<Server>(new Status(e), null);
+			// TODO: Log the exception
+			return errorResponse(e.getMessage());
 		}
-		return new GenericResponse<Server>(Status.STATUS_SUCCESS, server);
+	}
+	
+	private Server getDiscoveredServer(String serverName) {
+		Server server = new Server(serverName);
+		serverUtil.fetchServerDetails(server);
+		return server;
 	}
 	
 	public static void main(String[] args) {
-		StringListResponse listResponse = (StringListResponse)new DiscoveredServersResource().getDiscoveredServers(false);
-		for (String server : listResponse.getData()) {
-			System.out.println(server);
-		}
+		Response response = (Response)new DiscoveredServersResource().getDiscoveredServersXML(false);
+		System.out.println(response.getEntity());
 	}
 }
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/GlusterServersResource.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/GlusterServersResource.java
index 6e15e106..a9ef7fbb 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/GlusterServersResource.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/GlusterServersResource.java
@@ -18,13 +18,14 @@
  *******************************************************************************/
 package com.gluster.storage.management.server.resources;
 
-import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_CLUSTER_NAME;
 import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_SERVER_NAME;
-import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_SOURCE;
 import static com.gluster.storage.management.core.constants.RESTConstants.PATH_PARAM_CLUSTER_NAME;
+import static com.gluster.storage.management.core.constants.RESTConstants.PATH_PARAM_DISK_NAME;
 import static com.gluster.storage.management.core.constants.RESTConstants.PATH_PARAM_SERVER_NAME;
+import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_DISKS;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_PATH_CLUSTERS;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_SERVERS;
+import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_TASKS;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -33,6 +34,7 @@ import javax.ws.rs.DELETE;
 import javax.ws.rs.FormParam;
 import javax.ws.rs.GET;
 import javax.ws.rs.POST;
+import javax.ws.rs.PUT;
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
@@ -43,17 +45,16 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
 import com.gluster.storage.management.core.constants.CoreConstants;
+import com.gluster.storage.management.core.constants.RESTConstants;
 import com.gluster.storage.management.core.exceptions.ConnectionException;
 import com.gluster.storage.management.core.exceptions.GlusterRuntimeException;
 import com.gluster.storage.management.core.model.GlusterServer;
 import com.gluster.storage.management.core.model.GlusterServer.SERVER_STATUS;
-import com.gluster.storage.management.core.model.Status;
 import com.gluster.storage.management.core.response.GlusterServerListResponse;
-import com.gluster.storage.management.core.response.GlusterServerResponse;
-import com.gluster.storage.management.core.utils.LRUCache;
 import com.gluster.storage.management.server.data.ClusterInfo;
 import com.gluster.storage.management.server.data.ServerInfo;
 import com.gluster.storage.management.server.services.ClusterService;
+import com.gluster.storage.management.server.tasks.InitializeDiskTask;
 import com.gluster.storage.management.server.utils.GlusterUtil;
 import com.gluster.storage.management.server.utils.SshUtil;
 import com.sun.jersey.api.core.InjectParam;
@@ -65,128 +66,90 @@ import com.sun.jersey.spi.resource.Singleton;
 public class GlusterServersResource extends AbstractServersResource {
 
 	public static final String HOSTNAMETAG = "hostname:";
-	private LRUCache<String, GlusterServer> clusterServerCache = new LRUCache<String, GlusterServer>(3);
-	
+
 	@InjectParam
 	private DiscoveredServersResource discoveredServersResource;
-	
+
+	@InjectParam
+	private TasksResource taskResource;
+
 	@Autowired
 	private ClusterService clusterService;
-	
+
 	@Autowired
 	private SshUtil sshUtil;
-	
+
 	protected void fetchServerDetails(GlusterServer server) {
 		try {
 			server.setStatus(SERVER_STATUS.ONLINE);
-			super.fetchServerDetails(server);
-		} catch(ConnectionException e) {
+			serverUtil.fetchServerDetails(server);
+		} catch (ConnectionException e) {
 			server.setStatus(SERVER_STATUS.OFFLINE);
 		}
 	}
-	
-	public GlusterServer getOnlineServer(String clusterName) {
-		return getOnlineServer(clusterName, "");
-	}
-	
-	// uses cache
-	public GlusterServer getOnlineServer(String clusterName, String exceptServerName) {
-		GlusterServer server = clusterServerCache.get(clusterName);
-		if(server != null && !server.getName().equals(exceptServerName)) {
-			return server;
-		}
-		
-		return getNewOnlineServer(clusterName, exceptServerName);
-	}
 
-	public GlusterServer getNewOnlineServer(String clusterName) {
-		return getNewOnlineServer(clusterName, "");
-	}
 
-	// Doesn't use cache
-	public GlusterServer getNewOnlineServer(String clusterName, String exceptServerName) {
-		ClusterInfo cluster = clusterService.getCluster(clusterName);
-		if(cluster == null) {
-			return null;
-		}
-		
-		for(ServerInfo serverInfo : cluster.getServers()) {
-			GlusterServer server = new GlusterServer(serverInfo.getName());
-			fetchServerDetails(server);
-			if(server.isOnline() && !server.getName().equals(exceptServerName)) {
-				// server is online. add it to cache and return
-				clusterServerCache.put(clusterName, server);
-				return server;
-			}
-		}
-		
-		// no online server found.
-		return null;
-	}
-	
 	@GET
 	@Produces(MediaType.APPLICATION_JSON)
-	public Response getGlusterServersJSON(
-			@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName) {
+	public Response getGlusterServersJSON(@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName) {
 		return getGlusterServers(clusterName, MediaType.APPLICATION_JSON);
 	}
 
 	@GET
 	@Produces(MediaType.APPLICATION_XML)
-	public Response getGlusterServersXML(
-			@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName) {
+	public Response getGlusterServersXML(@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName) {
 		return getGlusterServers(clusterName, MediaType.APPLICATION_XML);
 	}
 
 	public Response getGlusterServers(String clusterName, String mediaType) {
 		List<GlusterServer> glusterServers = new ArrayList<GlusterServer>();
-		
+
 		if (clusterName == null || clusterName.isEmpty()) {
 			return badRequestResponse("Cluster name must not be empty!");
 		}
 
 		ClusterInfo cluster = clusterService.getCluster(clusterName);
 		if (cluster == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 
-		if(cluster.getServers().size() == 0) {
+		if (cluster.getServers().size() == 0) {
 			return okResponse(new GlusterServerListResponse(glusterServers), mediaType);
 		}
-		
-		GlusterServer onlineServer = getOnlineServer(clusterName);
+
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
 		if (onlineServer == null) {
 			return errorResponse("No online servers found in cluster [" + clusterName + "]");
 		}
-		
+
 		try {
 			glusterServers = getGlusterServers(clusterName, onlineServer);
-		} catch(ConnectionException e) {
+		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = getNewOnlineServer(clusterName);
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
 			if (onlineServer == null) {
 				return errorResponse("No online servers found in cluster [" + clusterName + "]");
 			}
 			try {
 				glusterServers = getGlusterServers(clusterName, onlineServer);
-			} catch(Exception e1) {
+			} catch (Exception e1) {
 				return errorResponse(e1.getMessage());
 			}
-		} catch(Exception e) {
+		} catch (Exception e) {
 			return errorResponse(e.getMessage());
 		}
-		
+
 		String errMsg = fetchDetailsOfServers(glusterServers, onlineServer);
-		if(!errMsg.isEmpty()) {
+		if (!errMsg.isEmpty()) {
 			return errorResponse("Couldn't fetch details for server(s): " + errMsg);
 		}
-		
+
 		return okResponse(new GlusterServerListResponse(glusterServers), mediaType);
 	}
 
 	public String fetchDetailsOfServers(List<GlusterServer> glusterServers, GlusterServer onlineServer) {
 		String errMsg = "";
-		
+
 		for (GlusterServer server : glusterServers) {
 			if (server.getStatus() == SERVER_STATUS.ONLINE && !server.getName().equals(onlineServer.getName())) {
 				try {
@@ -203,13 +166,13 @@ public class GlusterServersResource extends AbstractServersResource {
 		List<GlusterServer> glusterServers;
 		try {
 			glusterServers = glusterUtil.getGlusterServers(onlineServer);
-		} catch(ConnectionException e) {
+		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = getNewOnlineServer(clusterName);
-			if(onlineServer == null) {
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
+			if (onlineServer == null) {
 				throw new GlusterRuntimeException("No online servers found in cluster [" + clusterName + "]");
 			}
-			
+
 			glusterServers = glusterUtil.getGlusterServers(onlineServer);
 		}
 		return glusterServers;
@@ -218,8 +181,7 @@ public class GlusterServersResource extends AbstractServersResource {
 	@GET
 	@Path("{serverName}")
 	@Produces(MediaType.APPLICATION_XML)
-	public Response getGlusterServerXML(
-			@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName,
+	public Response getGlusterServerXML(@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName,
 			@PathParam(PATH_PARAM_SERVER_NAME) String serverName) {
 		return getGlusterServerResponse(clusterName, serverName, MediaType.APPLICATION_XML);
 	}
@@ -227,8 +189,7 @@ public class GlusterServersResource extends AbstractServersResource {
 	@GET
 	@Path("{serverName}")
 	@Produces(MediaType.APPLICATION_JSON)
-	public Response getGlusterServerJSON(
-			@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName,
+	public Response getGlusterServerJSON(@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName,
 			@PathParam(PATH_PARAM_SERVER_NAME) String serverName) {
 		return getGlusterServerResponse(clusterName, serverName, MediaType.APPLICATION_JSON);
 	}
@@ -236,7 +197,7 @@ public class GlusterServersResource extends AbstractServersResource {
 	private Response getGlusterServerResponse(String clusterName, String serverName, String mediaType) {
 		try {
 			return okResponse(getGlusterServer(clusterName, serverName), mediaType);
-		} catch(Exception e) {
+		} catch (Exception e) {
 			return errorResponse(e.getMessage());
 		}
 	}
@@ -255,93 +216,93 @@ public class GlusterServersResource extends AbstractServersResource {
 			throw new GlusterRuntimeException("Cluster [" + clusterName + "] not found!");
 		}
 
-		GlusterServer onlineServer = getOnlineServer(clusterName);
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
 		if (onlineServer == null) {
 			throw new GlusterRuntimeException("No online servers found in cluster [" + clusterName + "]");
 		}
-		
+
 		GlusterServer server = null;
 		try {
 			server = glusterUtil.getGlusterServer(onlineServer, serverName);
-		} catch(ConnectionException e) {
+		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = getNewOnlineServer(clusterName);
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
 			if (onlineServer == null) {
 				throw new GlusterRuntimeException("No online servers found in cluster [" + clusterName + "]");
 			}
 			server = glusterUtil.getGlusterServer(onlineServer, serverName);
 		}
-		
-		if(server.isOnline()) {
+
+		if (server.isOnline()) {
 			fetchServerDetails(server);
 		}
 		return server;
 	}
 
 	private void performAddServer(String clusterName, String serverName) {
-		GlusterServer onlineServer = getOnlineServer(clusterName);
-		if(onlineServer == null) {
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
+		if (onlineServer == null) {
 			throw new GlusterRuntimeException("No online server found in cluster [" + clusterName + "]");
 		}
-		
+
 		try {
 			glusterUtil.addServer(onlineServer.getName(), serverName);
-		} catch(ConnectionException e) {
+		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = getNewOnlineServer(clusterName);
-			if(onlineServer == null) {
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
+			if (onlineServer == null) {
 				throw new GlusterRuntimeException("No online server found in cluster [" + clusterName + "]");
 			}
-			
+
 			glusterUtil.addServer(serverName, onlineServer.getName());
 		}
 	}
-	
+
 	@POST
 	public Response addServer(@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName,
 			@FormParam(FORM_PARAM_SERVER_NAME) String serverName) {
-		if(clusterName == null || clusterName.isEmpty()) {
+		if (clusterName == null || clusterName.isEmpty()) {
 			return badRequestResponse("Cluster name must not be empty!");
 		}
-		
-		if(serverName == null || serverName.isEmpty()) {
+
+		if (serverName == null || serverName.isEmpty()) {
 			return badRequestResponse("Parameter [" + FORM_PARAM_SERVER_NAME + "] is missing in request!");
 		}
-		
+
 		ClusterInfo cluster = clusterService.getCluster(clusterName);
 		if (cluster == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
-		
+
 		boolean publicKeyInstalled = sshUtil.isPublicKeyInstalled(serverName);
-		if(!publicKeyInstalled && !sshUtil.hasDefaultPassword(serverName)) {
+		if (!publicKeyInstalled && !sshUtil.hasDefaultPassword(serverName)) {
 			// public key not installed, default password doesn't work. return with error.
 			return errorResponse("Gluster Management Gateway uses the default password to set up keys on the server."
 					+ CoreConstants.NEWLINE + "However it seems that the password on server [" + serverName
 					+ "] has been changed manually." + CoreConstants.NEWLINE
 					+ "Please reset it back to the standard default password and try again.");
 		}
-		
+
 		List<ServerInfo> servers = cluster.getServers();
-		if(servers != null && !servers.isEmpty()) {
+		if (servers != null && !servers.isEmpty()) {
 			// cluster has at least one existing server, so that peer probe can be performed
 			try {
 				performAddServer(clusterName, serverName);
-			} catch(Exception e) {
+			} catch (Exception e) {
 				return errorResponse(e.getMessage());
 			}
 		} else {
 			// this is the first server to be added to the cluster, which means no
 			// gluster CLI operation required. just add it to the cluster-server mapping
 		}
-		
+
 		try {
 			// add the cluster-server mapping
 			clusterService.mapServerToCluster(clusterName, serverName);
 		} catch (Exception e) {
 			return errorResponse(e.getMessage());
 		}
-		
+
 		// since the server is added to a cluster, it should not more be considered as a
 		// discovered server available to other clusters
 		discoveredServersResource.removeDiscoveredServer(serverName);
@@ -366,40 +327,39 @@ public class GlusterServersResource extends AbstractServersResource {
 		if (clusterName == null || clusterName.isEmpty()) {
 			return badRequestResponse("Cluster name must not be empty!");
 		}
-		
-		if(serverName == null || serverName.isEmpty()) {
+
+		if (serverName == null || serverName.isEmpty()) {
 			return badRequestResponse("Server name must not be empty!");
 		}
-		
+
 		ClusterInfo cluster = clusterService.getCluster(clusterName);
-		if(cluster == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+		if (cluster == null) {
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 
 		List<ServerInfo> servers = cluster.getServers();
-		if(servers == null || servers.isEmpty() || !containsServer(servers, serverName)) {
-			return badRequestResponse("Server [" + serverName + "] is not attached to cluster ["
-					+ clusterName + "]!");
+		if (servers == null || servers.isEmpty() || !containsServer(servers, serverName)) {
+			return badRequestResponse("Server [" + serverName + "] is not attached to cluster [" + clusterName + "]!");
 		}
-		
-		if(servers.size() == 1) {
+
+		if (servers.size() == 1) {
 			// Only one server mapped to the cluster, no "peer detach" required.
 			// remove the cached online server for this cluster if present
-			clusterServerCache.remove(clusterName);
+			clusterService.removeOnlineServer(clusterName);
 		} else {
 			try {
 				removeServerFromCluster(clusterName, serverName);
-			} catch(Exception e) {
+			} catch (Exception e) {
 				return errorResponse(e.getMessage());
 			}
-		}		
-		
+		}
+
 		return noContentResponse();
 	}
-	
+
 	private void removeServerFromCluster(String clusterName, String serverName) {
 		// get an online server that is not same as the server being removed
-		GlusterServer onlineServer = getOnlineServer(clusterName, serverName);
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName, serverName);
 		if (onlineServer == null) {
 			throw new GlusterRuntimeException("No online server found in cluster [" + clusterName + "]");
 		}
@@ -408,34 +368,63 @@ public class GlusterServersResource extends AbstractServersResource {
 			glusterUtil.removeServer(onlineServer.getName(), serverName);
 		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = getNewOnlineServer(clusterName, serverName);
+			onlineServer = clusterService.getNewOnlineServer(clusterName, serverName);
 			if (onlineServer == null) {
 				throw new GlusterRuntimeException("No online server found in cluster [" + clusterName + "]");
 			}
 			glusterUtil.removeServer(onlineServer.getName(), serverName);
 		}
-		
-		if(onlineServer.getName().equals(serverName)) {
+
+		if (onlineServer.getName().equals(serverName)) {
 			// since the cached server has been removed from the cluster, remove it from the cache
-			clusterServerCache.remove(clusterName);
+			clusterService.removeOnlineServer(clusterName);
 		}
-		
+
 		clusterService.unmapServerFromCluster(clusterName, serverName);
-		
-		// since the server is removed from the cluster, it is now available to be added to other clusters. 
+
+		// since the server is removed from the cluster, it is now available to be added to other clusters.
 		// Hence add it back to the discovered servers list.
-		discoveredServersResource.addDiscoveredServer(serverName);		
+		discoveredServersResource.addDiscoveredServer(serverName);
 	}
 
 	private boolean containsServer(List<ServerInfo> servers, String serverName) {
-		for(ServerInfo server : servers) {
-			if(server.getName().toUpperCase().equals(serverName.toUpperCase())) {
+		for (ServerInfo server : servers) {
+			if (server.getName().toUpperCase().equals(serverName.toUpperCase())) {
 				return true;
 			}
 		}
 		return false;
 	}
 
+	@PUT
+	@Produces(MediaType.APPLICATION_XML)
+	@Path("{" + PATH_PARAM_SERVER_NAME + "}/" + RESOURCE_DISKS + "/{" + PATH_PARAM_DISK_NAME + "}")
+	public Response initializeDisk(@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName,
+			@PathParam(PATH_PARAM_SERVER_NAME) String serverName, @PathParam(PATH_PARAM_DISK_NAME) String diskName) {
+
+		if (clusterName == null || clusterName.isEmpty()) {
+			return badRequestResponse("Cluster name must not be empty!");
+		}
+
+		if (serverName == null || serverName.isEmpty()) {
+			return badRequestResponse("Server name must not be empty!");
+		}
+
+		if (diskName == null || diskName.isEmpty()) {
+			return badRequestResponse("Disk name must not be empty!");
+		}
+
+		InitializeDiskTask initializeTask = new InitializeDiskTask(clusterService, clusterName, diskName, serverName);
+		try {
+			initializeTask.start();
+			taskResource.addTask(initializeTask);
+			return acceptedResponse(RESTConstants.RESOURCE_PATH_CLUSTERS + "/" + clusterName + "/" + RESOURCE_TASKS
+					+ "/" + initializeTask.getId());
+		} catch (ConnectionException e) {
+			return errorResponse(e.getMessage());
+		}
+	}
+
 	private void setGlusterUtil(GlusterUtil glusterUtil) {
 		this.glusterUtil = glusterUtil;
 	}
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/TasksResource.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/TasksResource.java
index 4bf1c0cf..53122f11 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/TasksResource.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/TasksResource.java
@@ -20,9 +20,9 @@
  */
 package com.gluster.storage.management.server.resources;
 
+import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_OPERATION;
 import static com.gluster.storage.management.core.constants.RESTConstants.PATH_PARAM_CLUSTER_NAME;
 import static com.gluster.storage.management.core.constants.RESTConstants.PATH_PARAM_TASK_ID;
-import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_OPERATION;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_PATH_CLUSTERS;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_TASKS;
 
@@ -40,26 +40,25 @@ import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
 import javax.ws.rs.QueryParam;
 import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
 
 import com.gluster.storage.management.core.constants.RESTConstants;
 import com.gluster.storage.management.core.exceptions.GlusterRuntimeException;
-import com.gluster.storage.management.core.model.Status;
-import com.gluster.storage.management.core.model.Task;
+import com.gluster.storage.management.core.exceptions.GlusterValidationException;
 import com.gluster.storage.management.core.model.TaskInfo;
-import com.gluster.storage.management.core.response.TaskListResponse;
-import com.gluster.storage.management.core.response.TaskResponse;
+import com.gluster.storage.management.core.response.TaskInfoListResponse;
+import com.gluster.storage.management.server.tasks.Task;
 import com.sun.jersey.spi.resource.Singleton;
 
 @Path(RESOURCE_PATH_CLUSTERS + "/{" + PATH_PARAM_CLUSTER_NAME + "}/" + RESOURCE_TASKS)
 @Singleton
-public class TasksResource {
+public class TasksResource extends AbstractResource {
 	private Map<String, Task> tasksMap = new HashMap<String, Task>();
 
 	public TasksResource() {
 	}
 
-	
-	public void addTask(Task task) { // task should be one of MuigrateDiskTask, FormatDiskTask, etc
+	public void addTask(Task task) {
 		tasksMap.put(task.getId(), task);
 	}
 
@@ -70,18 +69,11 @@ public class TasksResource {
 	public List<TaskInfo> getAllTasksInfo() {
 		List<TaskInfo> allTasksInfo = new ArrayList<TaskInfo>();
 		for (Map.Entry<String, Task> entry : tasksMap.entrySet()) {
-			allTasksInfo.add(entry.getValue().getTaskInfo());
+			checkTaskStatus(entry.getKey());
+			allTasksInfo.add(entry.getValue().getTaskInfo()); // TaskInfo with latest status 
 		}
 		return allTasksInfo;
 	}
-	
-	public List<Task> getAllTasks() {
-		List<Task> allTasks = new ArrayList<Task>();
-		for (Map.Entry<String, Task> entry : tasksMap.entrySet()) {
-			allTasks.add(entry.getValue());
-		}
-		return allTasks;
-	}
 
 	public Task getTask(String taskId) {
 		for (Map.Entry<String, Task> entry : tasksMap.entrySet()) {
@@ -91,63 +83,93 @@ public class TasksResource {
 		}
 		return null;
 	}
-
+	
 	@GET
 	@Produces(MediaType.APPLICATION_XML)
-	public TaskListResponse getTasks() {
-		TaskListResponse taskListResponse = new TaskListResponse();
+	public Response getTasks() {
+		try {
+			return okResponse(new TaskInfoListResponse(getAllTasksInfo()), MediaType.APPLICATION_XML);
+		} catch (GlusterRuntimeException e) {
+			return errorResponse(e.getMessage());
+		}
+	}
+	
+	@GET
+	@Path("/{" + PATH_PARAM_TASK_ID + "}")
+	@Produces(MediaType.APPLICATION_XML)
+	public Response getTaskStatus( @PathParam(PATH_PARAM_TASK_ID) String taskId) {
 		try {
-			taskListResponse.setData(getAllTasksInfo());
-			taskListResponse.setStatus(new Status(Status.STATUS_CODE_SUCCESS, ""));
+			Task task = checkTaskStatus(taskId);
+			return okResponse(task.getTaskInfo(), MediaType.APPLICATION_XML);
 		} catch (GlusterRuntimeException e) {
-			taskListResponse.setStatus(new Status(e));
+			return errorResponse(e.getMessage());
 		}
-		return taskListResponse;
+	}
+
+	private Task checkTaskStatus(String taskId) {
+		Task task = getTask(taskId);
+		task.getTaskInfo().setStatus(task.checkStatus());
+		return task;
 	}
 
 	@PUT
 	@Path("/{" + PATH_PARAM_TASK_ID + "}")
 	@Produces(MediaType.APPLICATION_XML)
-	public TaskResponse performTask(@PathParam(PATH_PARAM_TASK_ID) String taskId,
-			@FormParam(FORM_PARAM_OPERATION) String taskOperation) {
+	public Response performTask(@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName,
+			@PathParam(PATH_PARAM_TASK_ID) String taskId, @FormParam(FORM_PARAM_OPERATION) String taskOperation) {
 		Task task = getTask(taskId);
-		TaskInfo taskInfo = null;
-		TaskResponse taskResponse = new TaskResponse();
-
+		
 		try {
 			if (taskOperation.equals(RESTConstants.TASK_RESUME)) {
-				taskInfo = task.resume();
-			}
-			if (taskOperation.equals(RESTConstants.TASK_PAUSE)) {
-				taskInfo = task.pause();
+				task.resume();
+			} else if (taskOperation.equals(RESTConstants.TASK_PAUSE)) {
+				task.pause();
+			} else if (taskOperation.equals(RESTConstants.TASK_STOP)) {
+				task.stop();
+			} else if (taskOperation.equals(RESTConstants.TASK_COMMIT)) {
+				task.commit();
 			}
-			if (taskOperation.equals(RESTConstants.TASK_STOP)) {
-				taskInfo = task.stop();
-			}
-			taskResponse.setData(taskInfo);
-			taskResponse.setStatus(new Status(Status.STATUS_CODE_SUCCESS, ""));
+			return (Response) noContentResponse();
+		} catch(GlusterValidationException ve) {
+			return badRequestResponse(ve.getMessage());
 		} catch (GlusterRuntimeException e) {
-			taskResponse.setStatus(new Status(e));
+			return errorResponse(e.getMessage());
 		}
-		return taskResponse;
 	}
 
 	@DELETE
 	@Path("/{" + PATH_PARAM_TASK_ID + "}")
 	@Produces(MediaType.APPLICATION_XML)
-	public TaskResponse deleteTask(@PathParam(PATH_PARAM_TASK_ID) String taskId,
+	public Response deleteTask(@PathParam(PATH_PARAM_TASK_ID) String taskId,
 			@QueryParam(FORM_PARAM_OPERATION) String taskOperation) {
-		TaskResponse taskResponse = new TaskResponse();
 		Task task = getTask(taskId);
 		if (task == null) {
-			taskResponse.setStatus( new Status(Status.STATUS_CODE_FAILURE, "No such task " + taskId + "is found ")); 
+			return notFoundResponse("Task [" + taskId + "] not found!");
 		}
-		if (taskOperation.equals("delete")) {
-			removeTask(task);
-			taskResponse.setStatus(new Status(Status.STATUS_CODE_SUCCESS, "Task [" + taskId
-						+ "] removed successfully"));
-					}
-		return null;
-	}
+		
+		if(taskOperation == null || taskOperation.isEmpty()) {
+			return badRequestResponse("Parameter [" + FORM_PARAM_OPERATION + "] is missing in request!");
+		}
+		
+		if(!taskOperation.equals(RESTConstants.TASK_STOP) && !taskOperation.equals(RESTConstants.TASK_DELETE)) {
+			return badRequestResponse("Invalid value [" + taskOperation + "] for parameter [" + FORM_PARAM_OPERATION
+					+ "]");
+		}
+		
+		try {
+			if (taskOperation.equals(RESTConstants.TASK_STOP)) {
+				task.stop();
+				// On successfully stopping the task, we can delete (forget) it as it is no more useful
+				taskOperation = RESTConstants.TASK_DELETE;
+			}
 
+			if (taskOperation.equals(RESTConstants.TASK_DELETE)) {
+				removeTask(task);
+			}
+			
+			return noContentResponse();
+		} catch (Exception e) {
+			return errorResponse(e.getMessage());
+		}
+	}
 }
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/UsersResource.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/UsersResource.java
index 0326793b..0ccb4263 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/UsersResource.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/UsersResource.java
@@ -18,6 +18,9 @@
  *******************************************************************************/
 package com.gluster.storage.management.server.resources;
 
+import static com.gluster.storage.management.core.constants.RESTConstants.PATH_PARAM_USER;
+import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_PATH_USERS;
+
 import javax.ws.rs.FormParam;
 import javax.ws.rs.GET;
 import javax.ws.rs.PUT;
@@ -25,68 +28,60 @@ import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
 import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.security.authentication.encoding.PasswordEncoder;
-import org.springframework.security.core.AuthenticationException;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.security.provisioning.JdbcUserDetailsManager;
 import org.springframework.stereotype.Component;
 
-import com.gluster.storage.management.core.model.Status;
 import com.sun.jersey.spi.resource.Singleton;
 
 @Singleton
 @Component
-@Path("/users")
-public class UsersResource {
+@Path(RESOURCE_PATH_USERS)
+public class UsersResource extends AbstractResource {
 	@Autowired
 	private JdbcUserDetailsManager jdbcUserService;
 
 	@Autowired
 	private PasswordEncoder passwordEncoder;
 
-	/**
-	 * Authenticates given user with given password for login on current system
-	 * 
-	 * @param user
-	 * @param password
-	 * @return true is user can be successfully authenticated using given password, else false
-	 */
-	/*
-	 * NOTE: This method is no more required as user authentication is performed on every request by the spring security
-	 * framework. Can be removed after testing.
-	 */
-	/*
-	 * private boolean authenticate(String user, String password) { String tmpFileName = "tmp"; File saltFile = new
-	 * File(tmpFileName); ProcessResult result = new ProcessUtil().executeCommand("get-user-password.py", user,
-	 * tmpFileName); if (result.isSuccess()) { String salt = new FileUtil().readFileAsString(saltFile); String
-	 * encryptedPassword = MD5Crypt.crypt(password, salt); return encryptedPassword.equals(salt); }
-	 * 
-	 * return false; }
-	 */
-
-	@Path("{user}")
+	@Path("{" + PATH_PARAM_USER + "}")
 	@GET
 	@Produces(MediaType.APPLICATION_XML)
-	public Status authenticate(@PathParam("user") String user) {
+	public Response authenticateXML(@PathParam("user") String user) {
+		// success only if the user passed in query is same as the one passed in security header
+		// spring security would have already authenticated the user credentials
+		return getAuthenticationResponse(user, MediaType.APPLICATION_XML);
+	}
+
+	@Path("{" + PATH_PARAM_USER + "}")
+	@GET
+	@Produces(MediaType.APPLICATION_JSON)
+	public Response authenticateJSON(@PathParam("user") String user) {
 		// success only if the user passed in query is same as the one passed in security header
 		// spring security would have already authenticated the user credentials
-		return (SecurityContextHolder.getContext().getAuthentication().getName().equals(user) ? Status.STATUS_SUCCESS
-				: Status.STATUS_FAILURE);
+		return getAuthenticationResponse(user, MediaType.APPLICATION_JSON);
 	}
 
-	@Path("{user}")
+	public Response getAuthenticationResponse(String user, String mediaType) {
+		return (SecurityContextHolder.getContext().getAuthentication().getName().equals(user) ? okResponse(mediaType)
+				: unauthorizedResponse());
+	}
+
+	@Path("{" + PATH_PARAM_USER + "}")
 	@PUT
-	@Produces(MediaType.APPLICATION_XML)
-	public Status changePassword(@FormParam("oldpassword") String oldPassword,
+	public Response changePassword(@FormParam("oldpassword") String oldPassword,
 			@FormParam("newpassword") String newPassword) {
 		try {
 			jdbcUserService.changePassword(oldPassword, passwordEncoder.encodePassword(newPassword, null));
-		} catch (AuthenticationException ex) {
+		} catch (Exception ex) {
+			// TODO: Log the exception
 			ex.printStackTrace();
-			return new Status(Status.STATUS_CODE_FAILURE, "Could not change password: [" + ex.getMessage() + "]");
+			return errorResponse("Could not change password. Error: [" + ex.getMessage() + "]");
 		}
-		return Status.STATUS_SUCCESS;
+		return noContentResponse();
 	}
 }
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/VolumesResource.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/VolumesResource.java
index 5d1f38e9..c9ae0fe5 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/VolumesResource.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/resources/VolumesResource.java
@@ -23,8 +23,12 @@ package com.gluster.storage.management.server.resources;
 import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_ACCESS_PROTOCOLS;
 import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_AUTO_COMMIT;
 import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_BRICKS;
-import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_CLUSTER_NAME;
+import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_FIX_LAYOUT;
+import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_FORCED_DATA_MIGRATE;
+import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_MIGRATE_DATA;
 import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_OPERATION;
+import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_OPTION_KEY;
+import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_OPTION_VALUE;
 import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_REPLICA_COUNT;
 import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_SOURCE;
 import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_STRIPE_COUNT;
@@ -33,7 +37,6 @@ import static com.gluster.storage.management.core.constants.RESTConstants.FORM_P
 import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_VOLUME_NAME;
 import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_VOLUME_OPTIONS;
 import static com.gluster.storage.management.core.constants.RESTConstants.FORM_PARAM_VOLUME_TYPE;
-import static com.gluster.storage.management.core.constants.RESTConstants.*;
 import static com.gluster.storage.management.core.constants.RESTConstants.PATH_PARAM_CLUSTER_NAME;
 import static com.gluster.storage.management.core.constants.RESTConstants.PATH_PARAM_VOLUME_NAME;
 import static com.gluster.storage.management.core.constants.RESTConstants.QUERY_PARAM_BRICKS;
@@ -44,13 +47,13 @@ import static com.gluster.storage.management.core.constants.RESTConstants.QUERY_
 import static com.gluster.storage.management.core.constants.RESTConstants.QUERY_PARAM_LINE_COUNT;
 import static com.gluster.storage.management.core.constants.RESTConstants.QUERY_PARAM_LOG_SEVERITY;
 import static com.gluster.storage.management.core.constants.RESTConstants.QUERY_PARAM_TO_TIMESTAMP;
-import static com.gluster.storage.management.core.constants.RESTConstants.QUERY_PARAM_VOLUME_NAME;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_BRICKS;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_DEFAULT_OPTIONS;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_DOWNLOAD;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_LOGS;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_OPTIONS;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_PATH_CLUSTERS;
+import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_TASKS;
 import static com.gluster.storage.management.core.constants.RESTConstants.RESOURCE_VOLUMES;
 import static com.gluster.storage.management.core.constants.RESTConstants.TASK_START;
 import static com.gluster.storage.management.core.constants.RESTConstants.TASK_STOP;
@@ -91,16 +94,16 @@ import com.gluster.storage.management.core.model.Volume.VOLUME_TYPE;
 import com.gluster.storage.management.core.model.VolumeLogMessage;
 import com.gluster.storage.management.core.response.GenericResponse;
 import com.gluster.storage.management.core.response.LogMessageListResponse;
-import com.gluster.storage.management.core.response.TaskResponse;
 import com.gluster.storage.management.core.response.VolumeListResponse;
 import com.gluster.storage.management.core.response.VolumeOptionInfoListResponse;
 import com.gluster.storage.management.core.utils.DateUtil;
 import com.gluster.storage.management.core.utils.FileUtil;
-import com.gluster.storage.management.core.utils.GlusterCoreUtil;
 import com.gluster.storage.management.core.utils.ProcessUtil;
 import com.gluster.storage.management.server.constants.VolumeOptionsDefaults;
 import com.gluster.storage.management.server.data.ClusterInfo;
 import com.gluster.storage.management.server.services.ClusterService;
+import com.gluster.storage.management.server.tasks.MigrateDiskTask;
+import com.gluster.storage.management.server.tasks.RebalanceVolumeTask;
 import com.gluster.storage.management.server.utils.GlusterUtil;
 import com.gluster.storage.management.server.utils.ServerUtil;
 import com.sun.jersey.api.core.InjectParam;
@@ -109,14 +112,10 @@ import com.sun.jersey.spi.resource.Singleton;
 @Singleton
 @Path(RESOURCE_PATH_CLUSTERS + "/{" + PATH_PARAM_CLUSTER_NAME + "}/" + RESOURCE_VOLUMES)
 public class VolumesResource extends AbstractResource {
-	private static final String PREPARE_BRICK_SCRIPT = "create_volume_directory.py";
 	private static final String VOLUME_DIRECTORY_CLEANUP_SCRIPT = "clear_volume_directory.py";
 	private static final String VOLUME_BRICK_LOG_SCRIPT = "get_volume_brick_log.py";
 
 	@InjectParam
-	private GlusterServersResource glusterServersResource;
-
-	@InjectParam
 	private ServerUtil serverUtil;
 
 	@InjectParam
@@ -128,6 +127,9 @@ public class VolumesResource extends AbstractResource {
 	@InjectParam
 	private VolumeOptionsDefaults volumeOptionsDefaults;
 
+	@InjectParam
+	private TasksResource taskResource;
+	
 	@GET
 	@Produces({MediaType.APPLICATION_XML})
 	public Response getVolumesXML(@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName) {
@@ -145,15 +147,21 @@ public class VolumesResource extends AbstractResource {
 			return badRequestResponse("Cluster name must not be empty!");
 		}
 
-		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+		ClusterInfo cluster = clusterService.getCluster(clusterName);
+		if (cluster == null) {
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
+		}
+		
+		if(cluster.getServers().size() == 0) {
+			// no server added yet. return an empty array.
+			return okResponse(new VolumeListResponse(), mediaType);
 		}
 
 		return okResponse(getVolumes(clusterName), mediaType);
 	}
 
 	public VolumeListResponse getVolumes(String clusterName) {
-		GlusterServer onlineServer = glusterServersResource.getOnlineServer(clusterName);
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
 		if (onlineServer == null) {
 			return new VolumeListResponse(new ArrayList<Volume>());
 		}
@@ -162,7 +170,7 @@ public class VolumesResource extends AbstractResource {
 			return new VolumeListResponse(glusterUtil.getAllVolumes(onlineServer.getName()));
 		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = glusterServersResource.getNewOnlineServer(clusterName);
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
 			if (onlineServer == null) {
 				return new VolumeListResponse(new ArrayList<Volume>());
 			}
@@ -188,7 +196,7 @@ public class VolumesResource extends AbstractResource {
 		}
 
 		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 		
 		if (volumeType.equals(VOLUME_TYPE.DISTRIBUTED_MIRROR) && replicaCount <= 0) {
@@ -199,7 +207,7 @@ public class VolumesResource extends AbstractResource {
 			return badRequestResponse("Stripe count must be a positive integer");
 		}
 
-		GlusterServer onlineServer = glusterServersResource.getOnlineServer(clusterName);
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
 		if (onlineServer == null) {
 			return errorResponse("No online servers found in cluster [" + clusterName + "]");
 		}
@@ -209,7 +217,7 @@ public class VolumesResource extends AbstractResource {
 			return createdResponse(volumeName);
 		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = glusterServersResource.getNewOnlineServer(clusterName);
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
 			if (onlineServer == null) {
 				return errorResponse("No online servers found in cluster [" + clusterName + "]");
 			}
@@ -274,7 +282,7 @@ public class VolumesResource extends AbstractResource {
 		}
 
 		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 		
 		try {
@@ -287,7 +295,7 @@ public class VolumesResource extends AbstractResource {
 
 	private Volume getVolume(String clusterName, String volumeName) {
 		Volume volume;
-		GlusterServer onlineServer = glusterServersResource.getOnlineServer(clusterName);
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
 		if (onlineServer == null) {
 			throw new GlusterRuntimeException("No online servers found in cluster [" + clusterName + "]");
 		}
@@ -296,7 +304,7 @@ public class VolumesResource extends AbstractResource {
 			volume = glusterUtil.getVolume(volumeName, onlineServer.getName());
 		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = glusterServersResource.getNewOnlineServer(clusterName);
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
 			if (onlineServer == null) {
 				throw new GlusterRuntimeException("No online servers found in cluster [" + clusterName + "]");
 			}
@@ -309,7 +317,10 @@ public class VolumesResource extends AbstractResource {
 	@PUT
 	@Path("{" + PATH_PARAM_VOLUME_NAME + "}")
 	public Response performOperation(@PathParam(PATH_PARAM_CLUSTER_NAME) String clusterName,
-			@PathParam(PATH_PARAM_VOLUME_NAME) String volumeName, @FormParam(FORM_PARAM_OPERATION) String operation) {
+			@PathParam(PATH_PARAM_VOLUME_NAME) String volumeName, @FormParam(FORM_PARAM_OPERATION) String operation,
+			@FormParam(FORM_PARAM_FIX_LAYOUT) Boolean isFixLayout,
+			@FormParam(FORM_PARAM_MIGRATE_DATA) Boolean isMigrateData,
+			@FormParam(FORM_PARAM_FORCED_DATA_MIGRATE) Boolean isForcedDataMigrate) {
 		if (clusterName == null || clusterName.isEmpty()) {
 			return badRequestResponse("Cluster name must not be empty!");
 		}
@@ -319,31 +330,38 @@ public class VolumesResource extends AbstractResource {
 		}
 
 		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 		
-		GlusterServer onlineServer = glusterServersResource.getOnlineServer(clusterName);
-		if (onlineServer == null) {
-			return errorResponse("No online servers found in cluster [" + clusterName + "]");
+		try {
+			if (operation.equals(RESTConstants.TASK_REBALANCE_START)) {
+				String taskId = rebalanceStart(clusterName, volumeName, isFixLayout, isMigrateData, isForcedDataMigrate);
+				return acceptedResponse(RESTConstants.RESOURCE_PATH_CLUSTERS + "/" + clusterName + "/" + RESOURCE_TASKS
+						+ "/" + taskId);
+			} else if (operation.equals(RESTConstants.TASK_REBALANCE_STOP)) {
+				rebalanceStop(clusterName, volumeName);
+			} else {
+				performVolumeOperation(clusterName, volumeName, operation);
+			}
+			return noContentResponse();
+		} catch(Exception e) {
+			return errorResponse(e.getMessage());
 		}
-
+	}
+	
+	private void performVolumeOperation(String clusterName, String volumeName, String operation) {
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
 		try {
-			performOperation(volumeName, operation, onlineServer);			
-		} catch (ConnectionException e) {
-			// online server has gone offline! try with a different one.
-			onlineServer = glusterServersResource.getNewOnlineServer(clusterName);
 			if (onlineServer == null) {
-				return errorResponse("No online servers found in cluster [" + clusterName + "]");
-			}
-			
-			try {
-				performOperation(volumeName, operation, onlineServer);
-			} catch(Exception e1) {
-				// TODO: Log the exception
-				return errorResponse(e1.getMessage());
+				throw new GlusterRuntimeException("No online servers found in cluster [" + clusterName + "]");
 			}
+
+			performOperation(volumeName, operation, onlineServer);
+		} catch (ConnectionException e) {
+			// online server has gone offline! try with a different one.
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
+			performOperation(volumeName, operation, onlineServer);
 		}
-		return noContentResponse();
 	}
 
 	private Status performOperation(String volumeName, String operation, GlusterServer onlineServer) {
@@ -370,7 +388,7 @@ public class VolumesResource extends AbstractResource {
 		}
 		
 		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 		
 		if (deleteFlag == null) {
@@ -386,7 +404,7 @@ public class VolumesResource extends AbstractResource {
 		}
 		
 		List<Brick> bricks = volume.getBricks();
-		Status status = glusterUtil.deleteVolume(volumeName, glusterServersResource.getOnlineServer(clusterName)
+		Status status = glusterUtil.deleteVolume(volumeName, clusterService.getOnlineServer(clusterName)
 				.getName());
 		if(!status.isSuccess()) {
 			return errorResponse("Couldn't delete volume [" + volumeName + "]. Error: " + status);
@@ -423,14 +441,14 @@ public class VolumesResource extends AbstractResource {
 		}
 
 		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 		
 		if(deleteFlag == null) {
 			deleteFlag = false;
 		}
 
-		GlusterServer onlineServer = glusterServersResource.getOnlineServer(clusterName);
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
 		if (onlineServer == null) {
 			return errorResponse("No online servers found in cluster [" + clusterName + "]");
 		}
@@ -456,7 +474,7 @@ public class VolumesResource extends AbstractResource {
 			glusterUtil.removeBricks(volumeName, brickList, onlineServer.getName());
 		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = glusterServersResource.getNewOnlineServer(clusterName);
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
 			if (onlineServer == null) {
 				throw new GlusterRuntimeException("No online servers found in cluster [" + clusterName + "]");
 			}
@@ -530,10 +548,10 @@ public class VolumesResource extends AbstractResource {
 		}
 
 		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 		
-		GlusterServer onlineServer = glusterServersResource.getOnlineServer(clusterName);
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
 		if (onlineServer == null) {
 			return errorResponse("No online servers found in cluster [" + clusterName + "]");
 		}
@@ -542,7 +560,7 @@ public class VolumesResource extends AbstractResource {
 			glusterUtil.setOption(volumeName, key, value, onlineServer.getName());
 		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = glusterServersResource.getNewOnlineServer(clusterName);
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
 			if (onlineServer == null) {
 				return errorResponse("No online servers found in cluster [" + clusterName + "]");
 			}
@@ -572,10 +590,10 @@ public class VolumesResource extends AbstractResource {
 		}
 
 		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 
-		GlusterServer onlineServer = glusterServersResource.getOnlineServer(clusterName);
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
 		if (onlineServer == null) {
 			return errorResponse("No online servers found in cluster [" + clusterName + "]");
 		}
@@ -584,7 +602,7 @@ public class VolumesResource extends AbstractResource {
 			glusterUtil.resetOptions(volumeName, onlineServer.getName());
 		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = glusterServersResource.getNewOnlineServer(clusterName);
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
 			if (onlineServer == null) {
 				return errorResponse("No online servers found in cluster [" + clusterName + "]");
 			}
@@ -628,27 +646,20 @@ public class VolumesResource extends AbstractResource {
 		// Usage: get_volume_disk_log.py <volumeName> <diskName> <lineCount>
 		Object responseObj = serverUtil.executeOnServer(true, brick.getServerName(), VOLUME_BRICK_LOG_SCRIPT + " "
 				+ logFilePath + " " + lineCount, LogMessageListResponse.class);
-		Status status = null;
+
 		LogMessageListResponse response = null;
 		if (responseObj instanceof LogMessageListResponse) {
 			response = (LogMessageListResponse) responseObj;
-			status = response.getStatus();
+			// populate disk and trim other fields
+			List<VolumeLogMessage> logMessages = response.getLogMessages();
+			for (VolumeLogMessage logMessage : logMessages) {
+				logMessage.setBrickDirectory(brick.getBrickDirectory());
+			}
+			return logMessages;
 		} else {
-			status = (Status) responseObj;
-		}
-
-		if (!status.isSuccess()) {
+			Status status = (Status) responseObj;
 			throw new GlusterRuntimeException(status.toString());
 		}
-
-		// populate disk and trim other fields
-		List<VolumeLogMessage> logMessages = response.getLogMessages();
-		for (VolumeLogMessage logMessage : logMessages) {
-			logMessage.setBrickDirectory(brick.getBrickDirectory());
-			logMessage.setMessage(logMessage.getMessage().trim());
-			logMessage.setSeverity(logMessage.getSeverity().trim());
-		}
-		return logMessages;
 	}
 
 	@GET
@@ -665,7 +676,7 @@ public class VolumesResource extends AbstractResource {
 		}
 		
 		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 		
 		try {
@@ -757,7 +768,7 @@ public class VolumesResource extends AbstractResource {
 		}
 
 		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 
 		List<VolumeLogMessage> logMessages = null;
@@ -862,10 +873,10 @@ public class VolumesResource extends AbstractResource {
 		}
 
 		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 		
-		GlusterServer onlineServer = glusterServersResource.getOnlineServer(clusterName);
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
 		if (onlineServer == null) {
 			return errorResponse("No online servers found in cluster [" + clusterName + "]");
 		}
@@ -875,7 +886,7 @@ public class VolumesResource extends AbstractResource {
 			glusterUtil.addBricks(volumeName, brickList, onlineServer.getName());
 		} catch (ConnectionException e) {
 			// online server has gone offline! try with a different one.
-			onlineServer = glusterServersResource.getNewOnlineServer(clusterName);
+			onlineServer = clusterService.getNewOnlineServer(clusterName);
 			if (onlineServer == null) {
 				return errorResponse("No online servers found in cluster [" + clusterName + "]");
 			}
@@ -915,10 +926,10 @@ public class VolumesResource extends AbstractResource {
 		}
 		
 		if (clusterService.getCluster(clusterName) == null) {
-			return badRequestResponse("Cluster [" + clusterName + "] not found!");
+			return notFoundResponse("Cluster [" + clusterName + "] not found!");
 		}
 
-		GlusterServer onlineServer = glusterServersResource.getOnlineServer(clusterName);
+		GlusterServer onlineServer = clusterService.getOnlineServer(clusterName);
 		if (onlineServer == null) {
 			return errorResponse("No online servers found in cluster [" + clusterName + "]");
 		}
@@ -929,23 +940,54 @@ public class VolumesResource extends AbstractResource {
 		
 		String taskId = null;
 		try {
-			taskId = glusterUtil.migrateBrickStart(volumeName, fromBrick, toBrick, autoCommit, onlineServer.getName());
-		} catch (ConnectionException e) {
-			// online server has gone offline! try with a different one.
-			onlineServer = glusterServersResource.getNewOnlineServer(clusterName);
-			
-			try {
-				taskId = glusterUtil.migrateBrickStart(volumeName, fromBrick, toBrick, autoCommit, onlineServer.getName());
-			} catch(Exception e1) {
-				return errorResponse(e1.getMessage());
-			}
-		} catch(Exception e1) {
-			return errorResponse(e1.getMessage());
+			taskId = migrateBrickStart(clusterName, volumeName, fromBrick, toBrick, autoCommit);
+		}catch(Exception e) {
+			return errorResponse(e.getMessage());
 		}
 		
-		return acceptedResponse(RESTConstants.RESOURCE_PATH_CLUSTERS, clusterName, RESOURCE_TASKS, taskId);
+		return acceptedResponse(RESTConstants.RESOURCE_PATH_CLUSTERS + "/" + clusterName + "/" + RESOURCE_TASKS + "/"
+				+ taskId);
 	}
-
+	
+	private String migrateBrickStart(String clusterName, String volumeName, String fromBrick, String toBrick,
+			Boolean autoCommit) {
+		MigrateDiskTask migrateDiskTask = new MigrateDiskTask(clusterService, clusterName, volumeName, fromBrick,
+				toBrick);
+		migrateDiskTask.setAutoCommit(autoCommit);
+		migrateDiskTask.start();
+		taskResource.addTask(migrateDiskTask);
+		return migrateDiskTask.getTaskInfo().getName(); // Return Task ID
+	}
+	
+	private String rebalanceStart(String clusterName, String volumeName, Boolean isFixLayout, Boolean isMigrateData,
+			Boolean isForcedDataMigrate) {
+		String layout = "";
+		if (isForcedDataMigrate) {
+			layout = "forced-data-migrate";
+		} else if (isMigrateData) {
+			layout = "migrate-data";
+		} else if (isFixLayout) {
+			layout = "fix-layout";
+		}
+		
+		return rebalanceStart(clusterName, volumeName, layout);
+	}
+	
+	public String rebalanceStart(String clusterName, String volumeName, String layout) {
+		RebalanceVolumeTask rebalanceTask = new RebalanceVolumeTask(clusterService, clusterName, volumeName);
+		rebalanceTask.setLayout(layout);
+		rebalanceTask.start();
+		taskResource.addTask(rebalanceTask);
+		return rebalanceTask.getId();
+	}
+	
+	public void rebalanceStop(String clusterName, String volumeName) {
+		// TODO: arrive at the task id and fetch it
+		String taskId = "";
+		
+		taskResource.getTask(taskId).stop();
+	}
+	
 	public static void main(String[] args) throws ClassNotFoundException {
 		VolumesResource vr = new VolumesResource();
 		// VolumeListResponse response = vr.getAllVolumes();
@@ -969,6 +1011,10 @@ public class VolumesResource extends AbstractResource {
 		// System.out.println("Code : " + status.getCode());
 		// System.out.println("Message " + status.getMessage());
 
-		vr.removeBricks("testCluster", "test", "192.168.1.210:sdb", true);
+		// vr.removeBricks("testCluster", "test", "192.168.1.210:sdb", true);
+
+		String taskId = vr.migrateBrickStart("myGluster", "students", "devserver1:/export/sdc/students",
+				"devserver2:/export/sdb/students", true);
+		
 	}
 }
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/services/ClusterService.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/services/ClusterService.java
index 0aabb714..b622c3a1 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/services/ClusterService.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/services/ClusterService.java
@@ -33,15 +33,17 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
 import com.gluster.storage.management.core.constants.CoreConstants;
+import com.gluster.storage.management.core.exceptions.ConnectionException;
 import com.gluster.storage.management.core.exceptions.GlusterRuntimeException;
 import com.gluster.storage.management.core.model.GlusterServer;
-import com.gluster.storage.management.core.model.Status;
+import com.gluster.storage.management.core.model.GlusterServer.SERVER_STATUS;
+import com.gluster.storage.management.core.utils.LRUCache;
 import com.gluster.storage.management.server.data.ClusterInfo;
 import com.gluster.storage.management.server.data.PersistenceDao;
 import com.gluster.storage.management.server.data.ServerInfo;
 import com.gluster.storage.management.server.utils.GlusterUtil;
+import com.gluster.storage.management.server.utils.ServerUtil;
 import com.gluster.storage.management.server.utils.SshUtil;
-import com.sun.jersey.api.core.InjectParam;
 
 /**
  * Service class for functionality related to clusters
@@ -60,12 +62,70 @@ public class ClusterService {
 	@Autowired
 	private SshUtil sshUtil;
 	
+	@Autowired
+	private ServerUtil serverUtil;
+
+	private LRUCache<String, GlusterServer> onlineServerCache = new LRUCache<String, GlusterServer>(3);
+	
+	public void addOnlineServer(String clusterName, GlusterServer server) {
+		onlineServerCache.put(clusterName, server);
+	}
+	
+	public void removeOnlineServer(String clusterName) {
+		onlineServerCache.remove(clusterName);
+	}
+	
+	// uses cache
+	public GlusterServer getOnlineServer(String clusterName, String exceptServerName) {
+		GlusterServer server = onlineServerCache.get(clusterName);
+		if (server != null && !server.getName().equals(exceptServerName)) {
+			return server;
+		}
+
+		return getNewOnlineServer(clusterName, exceptServerName);
+	}
+
+	public GlusterServer getNewOnlineServer(String clusterName) {
+		return getNewOnlineServer(clusterName, "");
+	}
+	
+	public GlusterServer getOnlineServer(String clusterName) {
+		return getOnlineServer(clusterName, "");
+	}
+
+	// Doesn't use cache
+	public GlusterServer getNewOnlineServer(String clusterName, String exceptServerName) {
+		ClusterInfo cluster = getCluster(clusterName);
+		if (cluster == null) {
+			throw new GlusterRuntimeException("Cluster [" + clusterName + "] is not found!");
+		}
+
+		for (ServerInfo serverInfo : cluster.getServers()) {
+			GlusterServer server = new GlusterServer(serverInfo.getName());
+			server.setStatus(SERVER_STATUS.ONLINE);
+			try {
+				serverUtil.fetchServerDetails(server);
+				if (server.isOnline() && !server.getName().equals(exceptServerName)) {
+					// server is online. add it to cache and return
+					addOnlineServer(clusterName, server);
+					return server;
+				}
+			} catch(ConnectionException e) {
+				// server is offline. continue checking next one.
+				continue;
+			}
+		}
+
+		// no online server found.
+		throw new GlusterRuntimeException("No online server found in cluster [" + clusterName + "]");
+	}
+	
 	public List<ClusterInfo> getAllClusters() {
 		return clusterDao.findAll();
 	}
 	
 	public ClusterInfo getCluster(String clusterName) {
-		List<ClusterInfo> clusters = clusterDao.findBy("name = ?1", clusterName);
+		List<ClusterInfo> clusters = clusterDao.findBy("UPPER(name) = ?1", clusterName.toUpperCase());
 		if(clusters.size() == 0) {
 			return null;
 		}
@@ -74,7 +134,7 @@ public class ClusterService {
 	}
 	
 	public ClusterInfo getClusterForServer(String serverName) {
-		List<ServerInfo> servers = serverDao.findBy("name = ?1", serverName);
+		List<ServerInfo> servers = serverDao.findBy("UPPER(name) = ?1", serverName.toUpperCase());
 		if(servers.size() == 0) {
 			return null;
 		}
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/InitializeDiskTask.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/InitializeDiskTask.java
new file mode 100644
index 00000000..5f3f8e30
--- /dev/null
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/InitializeDiskTask.java
@@ -0,0 +1,114 @@
+/**
+ * InitializeDiskTask.java
+ *
+ * Copyright (c) 2011 Gluster, Inc. <http://www.gluster.com>
+ * This file is part of Gluster Management Console.
+ *
+ * Gluster Management Console is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Gluster Management Console is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+package com.gluster.storage.management.server.tasks;
+
+import com.gluster.storage.management.core.model.Status;
+import com.gluster.storage.management.core.model.TaskInfo;
+import com.gluster.storage.management.core.model.TaskInfo.TASK_TYPE;
+import com.gluster.storage.management.core.model.TaskStatus;
+import com.gluster.storage.management.server.services.ClusterService;
+import com.gluster.storage.management.server.utils.SshUtil;
+
+public class InitializeDiskTask extends Task {
+
+	private static final String INITIALIZE_DISK_SCRIPT = "initialize_disk.py";
+	private static final String INITIALIZE_DISK_STATUS_SCRIPT = "initialize_disk_status.py";
+	
+	private String serverName;
+	private String diskName;
+	private SshUtil sshUtil = new SshUtil();
+
+	public InitializeDiskTask(ClusterService clusterService, String clusterName, String serverName, String diskName) {
+		super(clusterService, clusterName, TASK_TYPE.DISK_FORMAT, diskName, "Initialize disk " + serverName + ":"
+				+ diskName, false, false, false);
+
+		setServerName(serverName);
+		setDiskName(diskName);
+	}
+
+	public InitializeDiskTask(ClusterService clusterService, String clusterName, TaskInfo info) {
+		super(clusterService, clusterName, info);
+	}
+
+	@Override
+	public String getId() {
+		return taskInfo.getType() + "-" + serverName + ":" + diskName;
+	}
+
+	@Override
+	public void resume() {
+		getTaskInfo().setStatus( new TaskStatus( new Status(Status.STATUS_CODE_FAILURE, "Can not resume disk initialization")));
+	}
+
+	@Override
+	public void stop() {
+		getTaskInfo().setStatus( new TaskStatus( new Status(Status.STATUS_CODE_FAILURE, "Can not stop disk initialization")));
+	}
+
+	@Override
+	public void pause() {
+		getTaskInfo().setStatus( new TaskStatus( new Status(Status.STATUS_CODE_FAILURE, "Can not suspend disk initialization")));
+	}
+	
+	@Override
+	public void commit() {
+		// TODO Auto-generated method stub
+	}
+
+	@Override
+	public TASK_TYPE getType() {
+		return TASK_TYPE.DISK_FORMAT;
+	}
+
+	@Override
+	public TaskInfo getTaskInfo() {
+		return getTaskInfo();
+	}
+
+	@Override
+	public void start() {
+		getTaskInfo().setStatus(
+				new TaskStatus(new Status(sshUtil.executeRemote(getServerName(), INITIALIZE_DISK_SCRIPT + " "
+						+ getDiskName()))));
+	}
+
+	@Override
+	public TaskStatus checkStatus() {
+		return new TaskStatus(new Status(sshUtil.executeRemote(getServerName(), INITIALIZE_DISK_STATUS_SCRIPT + " "
+				+ getDiskName())));
+	}
+
+	public void setDiskName(String diskName) {
+		this.diskName = diskName;
+	}
+
+	public String getDiskName() {
+		return diskName;
+	}
+
+	public void setServerName(String serverName) {
+		this.serverName = serverName;
+	}
+
+	public String getServerName() {
+		return serverName;
+	}
+}
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/MigrateDiskTask.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/MigrateDiskTask.java
index df637ab1..9bdc9c94 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/MigrateDiskTask.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/MigrateDiskTask.java
@@ -20,13 +20,16 @@
  */
 package com.gluster.storage.management.server.tasks;
 
-import org.springframework.beans.factory.annotation.Autowired;
-
+import com.gluster.storage.management.core.exceptions.ConnectionException;
+import com.gluster.storage.management.core.exceptions.GlusterRuntimeException;
 import com.gluster.storage.management.core.model.Status;
-import com.gluster.storage.management.core.model.Task;
 import com.gluster.storage.management.core.model.TaskInfo;
+import com.gluster.storage.management.core.model.TaskInfo.TASK_TYPE;
 import com.gluster.storage.management.core.model.TaskStatus;
+import com.gluster.storage.management.core.utils.ProcessResult;
+import com.gluster.storage.management.server.services.ClusterService;
 import com.gluster.storage.management.server.utils.SshUtil;
+import com.sun.jersey.core.util.Base64;
 
 public class MigrateDiskTask extends Task {
 
@@ -60,67 +63,176 @@ public class MigrateDiskTask extends Task {
 		this.autoCommit = autoCommit;
 	}
 
-	public MigrateDiskTask(TASK_TYPE type, String volumeName, String fromBrick, String toBrick) {
-		super(type, volumeName);
+	public MigrateDiskTask(ClusterService clusterService, String clusterName, String volumeName, String fromBrick, String toBrick) {
+		super(clusterService, clusterName, TASK_TYPE.BRICK_MIGRATE, volumeName, "Brick Migration on volume ["
+				+ volumeName + "] from [" + fromBrick + "] to [" + toBrick + "]", true, true, true);
 		setFromBrick(fromBrick);
 		setToBrick(toBrick);
-		setTaskDescription();
-		getTaskInfo().setCanPause(true);
-		getTaskInfo().setCanStop(true);
+		taskInfo.setName(getId());
 	}
 
-	public MigrateDiskTask(TaskInfo info) {
-		super(info);
-		setTaskDescription();
+	public MigrateDiskTask(ClusterService clusterService, String clusterName, TaskInfo info) {
+		super(clusterService, clusterName, info);
 	}
 
 	@Override
 	public String getId() {
-		return getTaskInfo().getId();
+		return new String( Base64.encode( taskInfo.getType() + "-" + taskInfo.getReference() + "-" + fromBrick + "-" + toBrick ));
 	}
 
 	@Override
-	public TaskInfo start() {
-		getTaskInfo().setStatus(
-				new TaskStatus(new Status(sshUtil.executeRemote(getOnlineServer(), "gluster volume replace-brick "
-						+ getTaskInfo().getReference() + " " + getFromBrick() + " " + getToBrick() + " start" ) )));
-		return getTaskInfo();
+	public void start() {
+		try {
+			startMigration(getOnlineServer().getName());
+		} catch(ConnectionException e) {
+			// online server might have gone offline. try with a new one.
+			startMigration(getNewOnlineServer().getName());
+		}
+	}
+
+	private void startMigration(String onlineServerName) {
+		String command = "gluster volume replace-brick " + getTaskInfo().getReference() + " " + getFromBrick() + " "
+				+ getToBrick() + " start";
+		ProcessResult processResult = sshUtil.executeRemote(onlineServerName, command);
+		if (processResult.isSuccess()) {
+			if (processResult.getOutput().trim().matches(".*started successfully$")) {
+				getTaskInfo().setStatus(new TaskStatus(new Status(Status.STATUS_CODE_RUNNING, processResult.getOutput().trim())));
+				return;
+			}
+		}
+		
+		// if we come here, it means task couldn't be started successfully.
+		throw new GlusterRuntimeException(processResult.toString());
 	}
 
 	@Override
-	public TaskInfo resume() {
-		return start();
+	public void pause() {
+		try {
+			pauseMigration(getOnlineServer().getName());
+		} catch(ConnectionException e) {
+			// online server might have gone offline. try with a new one.
+			pauseMigration(getNewOnlineServer().getName());
+		}
 	}
 
+	private void pauseMigration(String onlineServer) {
+		String command = "gluster volume replace-brick " + getTaskInfo().getReference() + " " + getFromBrick() + " " + getToBrick()
+		+ " pause";
+
+		ProcessResult processResult = sshUtil.executeRemote(onlineServer, command);
+		TaskStatus taskStatus = new TaskStatus();
+		if (processResult.isSuccess()) {
+			if (processResult.getOutput().matches("*pause")) { //TODO replace correct pattern to identify the pause status
+				taskStatus.setCode(Status.STATUS_CODE_PAUSE);
+				taskStatus.setMessage(processResult.getOutput());
+				getTaskInfo().setStatus(taskStatus);
+				return;
+			}
+		} 
+		
+		// if we reach here, it means rebalance start failed.
+		throw new GlusterRuntimeException(processResult.toString());
+	}
+	
+	
+	@Override
+	public void resume() {
+		start();
+	}
+	
 	@Override
-	public TaskInfo stop() {
-		getTaskInfo().setStatus(
-				new TaskStatus(new Status(sshUtil.executeRemote(getOnlineServer(), "gluster volume replace-brick "
-						+ getTaskInfo().getReference() + " " + getFromBrick() + " " + getToBrick() + " abort" ) )));
-		return getTaskInfo();
+	public void commit() {
+		try {
+			commitMigration(getOnlineServer().getName());
+		} catch(ConnectionException e) {
+			// online server might have gone offline. try with a new one.
+			commitMigration(getNewOnlineServer().getName());
+		}
 	}
 
 	@Override
-	public TaskInfo pause() {
-		getTaskInfo().setStatus(
-				new TaskStatus(new Status(sshUtil.executeRemote(getOnlineServer(), "gluster volume replace-brick "
-						+ getTaskInfo().getReference() + " " + getFromBrick() + " " + getToBrick() + " pause" ) )));
-		return getTaskInfo();
+	public void stop() {
+		try {
+			stopMigration(getOnlineServer().getName());
+		} catch(ConnectionException e) {
+			// online server might have gone offline. try with a new one.
+			stopMigration(getNewOnlineServer().getName());
+		}
+	}
+
+	private void stopMigration(String serverName) {
+		String command = "gluster volume replace-brick " + getTaskInfo().getReference() + " " + getFromBrick() + " " + getToBrick()
+		+ " abort";
+		
+		ProcessResult processResult = sshUtil.executeRemote(serverName, command);
+		TaskStatus taskStatus = new TaskStatus();
+		if (processResult.isSuccess()) {
+			if (processResult.getOutput().trim().matches(".*aborted successfully$")) {
+				taskStatus.setCode(Status.STATUS_CODE_SUCCESS);
+				taskStatus.setMessage(processResult.getOutput());
+				getTaskInfo().setStatus(taskStatus);
+				return;
+			} 
+		} 
 		
+		// if we reach here, it means rebalance start failed.
+		throw new GlusterRuntimeException(processResult.toString());
 	}
 
 	
 	@Override
-	public void setTaskDescription() {
-		TaskInfo taskInfo = getTaskInfo();
-		getTaskInfo().setDescription(
-				getTypeStr() + " on volume [" + taskInfo.getReference() + "] from [" + getFromBrick()
-						+ "] to [" + getToBrick() + "]");
+	public TaskStatus checkStatus() {
+		try {
+			return checkMigrationStatus(getOnlineServer().getName());
+		} catch(ConnectionException e) {
+			// online server might have gone offline. try with a new one.
+			return checkMigrationStatus(getNewOnlineServer().getName());
+		}
 	}
-
 	
-	@Override
-	public TaskInfo status() {
-		return getTaskInfo();
+	
+	public void commitMigration(String serverName) {
+		String command = "gluster volume replace-brick " + getTaskInfo().getReference() + " " + getFromBrick() + " "
+		+ getToBrick() + " commit";
+		
+		ProcessResult processResult = sshUtil.executeRemote(serverName, command);
+		TaskStatus taskStatus = new TaskStatus();
+		if (processResult.isSuccess()) {
+			if (processResult.getOutput().trim().matches(".*commit successful$")) {
+				taskStatus.setCode(Status.STATUS_CODE_SUCCESS);
+				taskStatus.setMessage(processResult.getOutput()); // Common
+				getTaskInfo().setStatus(taskStatus);
+				return;
+			}
+		}
+		
+		// if we reach here, it means rebalance start failed.
+		throw new GlusterRuntimeException(processResult.toString());
+	}
+	
+
+	private TaskStatus checkMigrationStatus(String serverName) {
+		String command = "gluster volume replace-brick " + getTaskInfo().getReference() + " " + getFromBrick() + " "
+				+ getToBrick() + " status";
+		ProcessResult processResult = sshUtil.executeRemote(serverName, command);
+		TaskStatus taskStatus = new TaskStatus();
+		if (processResult.isSuccess()) {
+			if (processResult.getOutput().trim().matches("^Number of files migrated.*Migration complete$")) {
+				taskStatus.setCode(Status.STATUS_CODE_COMMIT_PENDING);
+				if (autoCommit) {
+					commitMigration(serverName);
+				}
+			} else if (	processResult.getOutput().trim().matches("^Number of files migrated.*Current file=.*")) {
+				taskStatus.setCode(Status.STATUS_CODE_RUNNING);
+			} else {
+				taskStatus.setCode(Status.STATUS_CODE_FAILURE);
+			}
+		} else {
+			taskStatus.setCode(Status.STATUS_CODE_FAILURE);
+		}
+				
+		taskStatus.setMessage(processResult.getOutput()); // common
+		taskInfo.setStatus(taskStatus); // Update the task status
+		return taskStatus;
 	}
 }
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/RebalanceVolumeTask.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/RebalanceVolumeTask.java
new file mode 100644
index 00000000..7f9fb6bf
--- /dev/null
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/RebalanceVolumeTask.java
@@ -0,0 +1,153 @@
+/**
+ * RebalanceVolumeTask.java
+ *
+ * Copyright (c) 2011 Gluster, Inc. <http://www.gluster.com>
+ * This file is part of Gluster Management Console.
+ *
+ * Gluster Management Console is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Gluster Management Console is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+package com.gluster.storage.management.server.tasks;
+
+import com.gluster.storage.management.core.exceptions.ConnectionException;
+import com.gluster.storage.management.core.exceptions.GlusterRuntimeException;
+import com.gluster.storage.management.core.model.Status;
+import com.gluster.storage.management.core.model.TaskInfo;
+import com.gluster.storage.management.core.model.TaskInfo.TASK_TYPE;
+import com.gluster.storage.management.core.model.TaskStatus;
+import com.gluster.storage.management.core.utils.ProcessResult;
+import com.gluster.storage.management.server.services.ClusterService;
+import com.gluster.storage.management.server.utils.SshUtil;
+
+public class RebalanceVolumeTask extends Task {
+
+	private String layout;
+	private SshUtil sshUtil = new SshUtil();
+
+	public RebalanceVolumeTask(ClusterService clusterService, String clusterName, TaskInfo taskInfo) {
+		super(clusterService, clusterName, taskInfo);
+	}
+
+	public RebalanceVolumeTask(ClusterService clusterService, String clusterName, String volumeName) {
+		super(clusterService, clusterName, TASK_TYPE.VOLUME_REBALANCE, volumeName, "Volume rebalance running on " + volumeName, false, true, false);
+	}
+
+	@Override
+	public String getId() {
+		return taskInfo.getType() + "-" + taskInfo.getReference();
+	}
+
+	@Override
+	public void start() {
+		try {
+			startRebalance(getOnlineServer().getName());
+		} catch(ConnectionException e) {
+			// online server might have gone offline. try with a new one
+			startRebalance(getNewOnlineServer().getName());
+		}
+	}
+
+	private void startRebalance(String serverName) {
+		String command = "gluster volume rebalance " + getTaskInfo().getReference() + " " + getLayout() + " start";
+		ProcessResult processResult = sshUtil.executeRemote(serverName, command);
+		if (processResult.isSuccess()) {
+			if (processResult.getOutput().trim().matches(".*has been successful$")) {
+				getTaskInfo().setStatus(new TaskStatus(new Status(Status.STATUS_CODE_RUNNING, processResult.getOutput())));
+			}
+		}
+		
+		// if we reach here, it means rebalance start failed.
+		throw new GlusterRuntimeException(processResult.toString());
+	}
+
+	@Override
+	public void resume() {
+		getTaskInfo().setStatus(
+				new TaskStatus(new Status(Status.STATUS_CODE_FAILURE, "Pause/Resume is not supported in Volume Rebalance")));
+	}
+
+	@Override
+	public void stop() {
+		try {
+			stopRebalance(getOnlineServer().getName());
+		} catch(ConnectionException e) {
+			// online server might have gone offline. try with a new one
+			stopRebalance(getNewOnlineServer().getName());
+		}
+	}
+
+	private void stopRebalance(String serverName) {
+		String command = "gluster volume rebalance " + getTaskInfo().getReference() + " stop";
+		ProcessResult processResult = sshUtil.executeRemote(serverName, command);
+		TaskStatus taskStatus = new TaskStatus();
+		if (processResult.isSuccess()) {
+			if (processResult.getOutput().trim().matches(".*has been successful$")) {
+				taskStatus.setCode(Status.STATUS_CODE_SUCCESS);
+			} else {
+				taskStatus.setCode(Status.STATUS_CODE_FAILURE);
+			}
+		} else {
+			taskStatus.setCode(Status.STATUS_CODE_FAILURE);
+		}
+		taskStatus.setMessage(processResult.getOutput()); // Common
+		getTaskInfo().setStatus(taskStatus);
+	}
+
+	@Override
+	public void pause() {
+		getTaskInfo().setStatus(
+				new TaskStatus(new Status(Status.STATUS_CODE_FAILURE, "Pause/Resume is not supported in Volume Rebalance")));
+	}
+
+	@Override
+	public TaskStatus checkStatus() {
+		try {
+			return checkRebalanceStatus(getOnlineServer().getName());
+		} catch(ConnectionException e) {
+			// online server might have gone offline. try with a new one. 
+			return checkRebalanceStatus(getNewOnlineServer().getName());
+		}
+	}
+	
+	// TODO: This method should move to glusterUtil
+	private TaskStatus checkRebalanceStatus(String serverName) {
+		String command = "gluster volume rebalance " + getTaskInfo().getReference() + " status";
+		ProcessResult processResult = sshUtil.executeRemote(serverName, command);
+		TaskStatus taskStatus = new TaskStatus();
+		if (processResult.isSuccess()) {
+			if (processResult.getOutput().trim().matches(".*rebalance completed$")) {
+				taskStatus.setCode(Status.STATUS_CODE_SUCCESS);
+			} else {
+				taskStatus.setCode(Status.STATUS_CODE_RUNNING);
+			}
+		} else {
+			taskStatus.setCode(Status.STATUS_CODE_FAILURE);
+		}
+		taskStatus.setMessage(processResult.getOutput()); // Common
+		return taskStatus;
+	}
+
+	public void setLayout(String layout) {
+		this.layout = layout;
+	}
+
+	public String getLayout() {
+		return layout;
+	}
+
+	@Override
+	public void commit() {
+		// TODO Auto-generated method stub
+	}
+}
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/Task.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/Task.java
new file mode 100644
index 00000000..49cd0b8b
--- /dev/null
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/tasks/Task.java
@@ -0,0 +1,111 @@
+/**
+ * Task.java
+ *
+ * Copyright (c) 2011 Gluster, Inc. <http://www.gluster.com>
+ * This file is part of Gluster Management Console.
+ *
+ * Gluster Management Console is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Gluster Management Console is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+package com.gluster.storage.management.server.tasks;
+
+import com.gluster.storage.management.core.model.GlusterServer;
+import com.gluster.storage.management.core.model.TaskInfo;
+import com.gluster.storage.management.core.model.TaskInfo.TASK_TYPE;
+import com.gluster.storage.management.core.model.TaskStatus;
+import com.gluster.storage.management.server.services.ClusterService;
+
+public abstract class Task {
+	public String[] TASK_TYPE_STR = { "Format Disk", "Migrate Brick", "Volume Rebalance" };
+	
+	protected TaskInfo taskInfo;	
+	protected String clusterName;
+	private ClusterService clusterService;
+	
+	public Task(ClusterService clusterService, String clusterName, TASK_TYPE type, String reference, String desc, boolean canPause, boolean canStop, boolean canCommit) {
+		TaskInfo taskInfo = new TaskInfo();
+		taskInfo.setType(type);
+		taskInfo.setReference(reference);
+		taskInfo.setDescription(desc);
+		taskInfo.setCanPause(canPause);
+		taskInfo.setCanStop(canStop);
+		taskInfo.setCanCommit(canCommit);
+		
+		init(clusterService, clusterName, taskInfo);
+		
+	}
+	
+	public Task(ClusterService clusterService, String clusterName, TaskInfo taskInfo) {
+		init(clusterService, clusterName, taskInfo);
+	}
+	
+	private void init(ClusterService clusterService, String clusterName, TaskInfo taskInfo) {
+		this.clusterService = clusterService;
+		setClusterName(clusterName);
+		setTaskInfo(taskInfo);
+	}
+	
+	protected GlusterServer getOnlineServer() {
+		return clusterService.getOnlineServer(clusterName);
+	}
+	
+	protected GlusterServer getNewOnlineServer() {
+		return clusterService.getNewOnlineServer(clusterName);
+	}
+	
+	protected GlusterServer getNewOnlineServer(String exceptServerName) {
+		return clusterService.getNewOnlineServer(clusterName, exceptServerName);
+	}
+
+	public String getTypeStr() {
+		return TASK_TYPE_STR[taskInfo.getType().ordinal()];
+	}
+	
+	public TASK_TYPE getType() {
+		return getTaskInfo().getType();
+	}
+	
+	public String getClusterName() {
+		return clusterName;
+	}
+	
+	public void setClusterName(String clusterName) {
+		this.clusterName = clusterName;
+	}
+	
+	public TaskInfo getTaskInfo() {
+		return taskInfo;
+	}
+	
+	public void setTaskInfo(TaskInfo info) {
+		this.taskInfo = info;  
+	}
+	
+	public abstract String getId();
+
+	public abstract void start(); 
+	
+	public abstract void resume();
+
+	public abstract void stop();
+
+	public abstract void pause();
+	
+	public abstract void commit();
+
+	/**
+	 * This method should check current status of the task and update it's taskInfo accordingly
+	 */
+	public abstract TaskStatus checkStatus();
+}
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/GlusterUtil.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/GlusterUtil.java
index 670ffb5c..788e3eab 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/GlusterUtil.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/GlusterUtil.java
@@ -36,7 +36,6 @@ import com.gluster.storage.management.core.model.Brick.BRICK_STATUS;
 import com.gluster.storage.management.core.model.GlusterServer;
 import com.gluster.storage.management.core.model.GlusterServer.SERVER_STATUS;
 import com.gluster.storage.management.core.model.Status;
-import com.gluster.storage.management.core.model.Task.TASK_TYPE;
 import com.gluster.storage.management.core.model.TaskInfo;
 import com.gluster.storage.management.core.model.Volume;
 import com.gluster.storage.management.core.model.Volume.TRANSPORT_TYPE;
@@ -47,6 +46,7 @@ import com.gluster.storage.management.core.utils.ProcessResult;
 import com.gluster.storage.management.core.utils.StringUtil;
 import com.gluster.storage.management.server.resources.TasksResource;
 import com.gluster.storage.management.server.tasks.MigrateDiskTask;
+import com.gluster.storage.management.server.tasks.RebalanceVolumeTask;
 import com.sun.jersey.api.core.InjectParam;
 
 @Component
@@ -536,21 +536,6 @@ public class GlusterUtil {
 		return logFileName;
 	}
 
-	
-	public String migrateBrickStart(String volumeName, String fromBrick, String toBrick, Boolean autoCommit,
-			String knownServer) {
-		MigrateDiskTask migrateDiskTask = new MigrateDiskTask(TASK_TYPE.BRICK_MIGRATE, volumeName, fromBrick, toBrick);
-		migrateDiskTask.setOnlineServer(knownServer);
-		migrateDiskTask.setAutoCommit(autoCommit);
-
-		TaskInfo taskInfo = migrateDiskTask.start();
-		if (taskInfo.isSuccess()) {
-			taskResource.addTask(migrateDiskTask);
-		}
-		
-		return taskInfo.getId();
-	}
-
 	public Status removeBricks(String volumeName, List<String> bricks, String knownServer) {
 		StringBuilder command = new StringBuilder("gluster --mode=script volume remove-brick " + volumeName);
 		for (String brickDir : bricks) {
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/ServerUtil.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/ServerUtil.java
index ed1aea75..ed77def3 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/ServerUtil.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/ServerUtil.java
@@ -42,6 +42,7 @@ import org.springframework.stereotype.Component;
 import com.gluster.storage.management.core.constants.CoreConstants;
 import com.gluster.storage.management.core.exceptions.ConnectionException;
 import com.gluster.storage.management.core.exceptions.GlusterRuntimeException;
+import com.gluster.storage.management.core.model.Server;
 import com.gluster.storage.management.core.model.Status;
 import com.gluster.storage.management.core.response.GenericResponse;
 import com.gluster.storage.management.core.utils.ProcessResult;
@@ -76,6 +77,21 @@ public class ServerUtil {
 		String scriptPath = servletContext.getRealPath(SCRIPT_DIR) + CoreConstants.FILE_SEPARATOR + scriptName;
 		return scriptPath;
 	}
+	
+	/**
+	 * Fetch details of the given server. The server name must be populated in the object before calling this method.
+	 * 
+	 * @param server
+	 *            Server whose details are to be fetched
+	 */
+	public void fetchServerDetails(Server server) {
+		// fetch standard server details like cpu, disk, memory details
+		Object response = executeOnServer(true, server.getName(), "get_server_details.py --only-data-disks", Server.class);
+		if (response instanceof Status) {
+			throw new GlusterRuntimeException(((Status)response).getMessage());
+		}
+		server.copyFrom((Server) response); // Update the details in <Server> object
+	}
 
 	/**
 	 * Executes given command on given server
diff --git a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/SshUtil.java b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/SshUtil.java
index 5f8b88f6..d56cd47c 100644
--- a/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/SshUtil.java
+++ b/src/com.gluster.storage.management.server/src/com/gluster/storage/management/server/utils/SshUtil.java
@@ -20,14 +20,14 @@ package com.gluster.storage.management.server.utils;
 
 import java.io.BufferedReader;
 import java.io.File;
-import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.UnsupportedEncodingException;
 import java.util.Arrays;
-import java.util.Date;
 
+import org.apache.log4j.Logger;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
 import ch.ethz.ssh2.ChannelCondition;
@@ -61,6 +61,15 @@ public class SshUtil {
 	private static final String USER_NAME = "root";
 	// TODO: Make default password configurable
 	private static final String DEFAULT_PASSWORD = "syst3m";
+	
+	private static final Logger logger = Logger.getLogger(SshUtil.class);
+	
+	@Autowired
+	private Integer sshConnectTimeout;
+	@Autowired
+	private Integer sshKexTimeout;
+	@Autowired
+	private Integer sshExecTimeout;
 
 	public boolean hasDefaultPassword(String serverName) {
 		try {
@@ -209,29 +218,28 @@ public class SshUtil {
 		Connection conn;
 		conn = new Connection(serverName);
 		try {
-			// tcp connection timeout = 3 sec, ssh connection timeout = 10 sec
-			conn.connect(null, 3000, 10000);
+			conn.connect(null, sshConnectTimeout, sshKexTimeout);
 		} catch (IOException e) {
-			e.printStackTrace();
+			logger.error("Couldn't establish SSH connection with server [" + serverName + "]", e);
 			throw new ConnectionException("Exception while creating SSH connection with server [" + serverName + "]", e);
 		}
 		return conn;
 	}
 
-	private boolean wasTerminated(int condition) {
-		return ((condition | ChannelCondition.EXIT_SIGNAL) == condition);
-	}
-
 	private boolean hasErrors(int condition, Session session) {
 		return (hasErrorStream(condition) || (exitedGracefully(condition) && exitedWithError(session)));
 	}
+	
+	private boolean timedOut(int condition) {
+		return (condition == ChannelCondition.TIMEOUT);
+	}
 
 	private boolean exitedWithError(Session session) {
 		return session.getExitStatus() != ProcessResult.SUCCESS;
 	}
 
 	private boolean exitedGracefully(int condition) {
-		return (condition | ChannelCondition.EXIT_STATUS) == condition;
+		return (condition == ChannelCondition.EXIT_STATUS);
 	}
 
 	private boolean hasErrorStream(int condition) {
@@ -250,8 +258,10 @@ public class SshUtil {
 			session.close();
 			return result;
 		} catch (IOException e) {
-			throw new GlusterRuntimeException("Exception while executing command [" + command + "] on ["
-					+ sshConnection.getHostname() + "]", e);
+			String errMsg = "Exception while executing command [" + command + "] on [" + sshConnection.getHostname()
+					+ "]";
+			logger.error(errMsg, e);
+			throw new GlusterRuntimeException(errMsg, e);
 		}
 	}
 
@@ -259,41 +269,51 @@ public class SshUtil {
 		// Wait for program to come out either
 		// a) gracefully with an exit status, OR
 		// b) because of a termination signal
-		int condition = session.waitForCondition(ChannelCondition.EXIT_SIGNAL | ChannelCondition.EXIT_STATUS, 5000);
+		// c) command takes to long to exit (timeout)
+		int condition = session.waitForCondition(ChannelCondition.EXIT_SIGNAL | ChannelCondition.EXIT_STATUS,
+				sshExecTimeout);
 		StringBuilder output = new StringBuilder();
 
 		try {
-			readFromStream(stdoutReader, output);
-			if (hasErrors(condition, session)) {
-				readFromStream(stderrReader, output);
+			if(!timedOut(condition)) {
+				readFromStream(stdoutReader, output);
+				if (hasErrors(condition, session)) {
+					readFromStream(stderrReader, output);
+				}
 			}
 
-			return prepareProcessResult(session, condition, output);
+			return prepareProcessResult(session, condition, output.toString().trim());
 		} catch (IOException e) {
-			// TODO Auto-generated catch block
-			e.printStackTrace();
-			return null;
+			String errMsg = "Error while reading output stream from SSH connection!";
+			logger.error(errMsg, e);
+			return new ProcessResult(ProcessResult.FAILURE, errMsg);
 		}
 	}
 
-	private ProcessResult prepareProcessResult(Session session, int condition, StringBuilder output) {
+	private ProcessResult prepareProcessResult(Session session, int condition, String output) {
 		ProcessResult result = null;
-		if (wasTerminated(condition)) {
-			result = new ProcessResult(ProcessResult.FAILURE, output.toString());
-		} else {
+		switch(condition) {
+		case ChannelCondition.TIMEOUT:
+			result = new ProcessResult(ProcessResult.FAILURE, "Command timed out!");
+			break;
+		case ChannelCondition.EXIT_SIGNAL:
+			// terminated
+			result = new ProcessResult(ProcessResult.FAILURE, output);
+			break;
+		default:
 			if (hasErrors(condition, session)) {
 				Integer exitStatus = session.getExitStatus();
 				int statusCode = (exitStatus == null ? ProcessResult.FAILURE : exitStatus);
-				result = new ProcessResult(statusCode, output.toString());
+				result = new ProcessResult(statusCode, output);
 			} else {
-				result = new ProcessResult(ProcessResult.SUCCESS, output.toString());
+				result = new ProcessResult(ProcessResult.SUCCESS, output);
 			}
+			break;
 		}
 		return result;
 	}
 
-	private void readFromStream(BufferedReader streamReader, StringBuilder output) throws IOException,
-			UnsupportedEncodingException {
+	private void readFromStream(BufferedReader streamReader, StringBuilder output) throws IOException {
 		while (true) {
 			String line = streamReader.readLine();
 			if (line == null) {
diff --git a/src/com.gluster.storage.management.server/src/log4j.properties b/src/com.gluster.storage.management.server/src/log4j.properties
index d7712c96..f84009d3 100644
--- a/src/com.gluster.storage.management.server/src/log4j.properties
+++ b/src/com.gluster.storage.management.server/src/log4j.properties
@@ -7,6 +7,13 @@ log4j.appender.CONSOLE.threshold=DEBUG
 log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
 log4j.appender.CONSOLE.layout.ConversionPattern=%d{dd MMM, yyyy HH:mm:ss} %p: %c %t - %m%n
 
+log4j.appender.R=org.apache.log4j.RollingFileAppender 
+log4j.appender.R.File=${catalina.home}/logs/tomcat.log 
+log4j.appender.R.MaxFileSize=10MB 
+log4j.appender.R.MaxBackupIndex=10 
+log4j.appender.R.layout=org.apache.log4j.PatternLayout 
+log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n
+
 log4j.logger.org.springframework=ERROR
 log4j.logger.org.springframework.aop=DEBUG
 log4j.logger.com.gluster=INFO
\ No newline at end of file
diff --git a/src/com.gluster.storage.management.server/src/spring/gluster-server-base.xml b/src/com.gluster.storage.management.server/src/spring/gluster-server-base.xml
index 3c7d6436..700d996f 100644
--- a/src/com.gluster.storage.management.server/src/spring/gluster-server-base.xml
+++ b/src/com.gluster.storage.management.server/src/spring/gluster-server-base.xml
@@ -21,6 +21,20 @@
 		<constructor-arg value="vmware" />
 	</bean>
 
+	<!-- SSH timeouts - all in milliseconds. zero means no timeout. -->
+	<!-- Connect the underlying TCP socket to the server with the given timeout value (SSH) -->
+	<bean id="sshConnectTimeout" class="java.lang.Integer">
+		<constructor-arg value="10000" />
+	</bean>
+	<!-- Timeout for complete connection establishment (SSH) -->
+	<bean id="sshKexTimeout" class="java.lang.Integer">
+		<constructor-arg value="60000" />
+	</bean>
+	<!-- Command execution timeout (SSH) -->
+	<bean id="sshExecTimeout" class="java.lang.Integer">
+		<constructor-arg value="120000" />
+	</bean>
+	
 	<!-- Gluster Management Gateway Version -->
 	<bean id="appVersion" class="java.lang.String">
 		<constructor-arg value="1.0.0" />