Renamed projects / packages com.gluster.* to org.gluster.*

6 files changed, 1001 insertions, 0 deletions

diff --git a/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/InitServerTask.java b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/InitServerTask.java
new file mode 100644
index 00000000..3193d926
--- /dev/null
+++ b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/InitServerTask.java
@@ -0,0 +1,161 @@
+/**
+ * GlusterServerInitializer.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 org.gluster.storage.management.gateway.tasks;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import javax.servlet.ServletContext;
+
+import org.apache.derby.tools.ij;
+import org.gluster.storage.management.core.constants.CoreConstants;
+import org.gluster.storage.management.core.exceptions.GlusterRuntimeException;
+import org.gluster.storage.management.gateway.data.ClusterInfo;
+import org.gluster.storage.management.gateway.data.PersistenceDao;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.jdbc.core.RowCallbackHandler;
+import org.springframework.jdbc.core.support.JdbcDaoSupport;
+import org.springframework.security.authentication.dao.SaltSource;
+import org.springframework.security.authentication.encoding.PasswordEncoder;
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.security.core.userdetails.UserDetailsService;
+
+
+/**
+ * Initializes the Gluster Management Server.
+ */
+public class InitServerTask extends JdbcDaoSupport {
+	@Autowired
+	private PasswordEncoder passwordEncoder;
+	
+	@Autowired
+	private SaltSource saltSource;
+	
+	@Autowired
+	private UserDetailsService userDetailsService;
+
+	@Autowired
+	private String appVersion;
+
+	@Autowired
+	private PersistenceDao<ClusterInfo> clusterDao;
+
+	@Autowired
+	ServletContext servletContext;
+
+	private static final String SCRIPT_DIR = "data/scripts/";
+
+	public void securePasswords() {
+		getJdbcTemplate().query("select username, password from users", new RowCallbackHandler() {
+			@Override
+			public void processRow(ResultSet rs) throws SQLException {
+				String username = rs.getString(1);
+				String password = rs.getString(2);
+				UserDetails user = userDetailsService.loadUserByUsername(username);
+				
+				String encodedPassword = passwordEncoder.encodePassword(password, saltSource.getSalt(user));
+				getJdbcTemplate().update("update users set password = ? where username = ?", encodedPassword, username);
+				logger.debug("Updating password for username: " + username);
+			}
+		});
+	}
+
+	private void executeScript(File script) {
+		ByteArrayOutputStream sqlOut = new ByteArrayOutputStream();
+		int numOfExceptions;
+		try {
+			numOfExceptions = ij.runScript(getJdbcTemplate().getDataSource().getConnection(), new FileInputStream(
+					script), CoreConstants.ENCODING_UTF8, sqlOut, CoreConstants.ENCODING_UTF8);
+			String output = sqlOut.toString();
+			sqlOut.close();
+			logger.debug("Data script [" + script.getName() + "] returned with exit status [" + numOfExceptions
+					+ "] and output [" + output + "]");
+			if (numOfExceptions != 0) {
+				throw new GlusterRuntimeException("Server data initialization script [ " + script.getName()
+						+ "] failed with [" + numOfExceptions + "] exceptions! [" + output + "]");
+			}
+		} catch (Exception ex) {
+			throw new GlusterRuntimeException("Server data initialization script [" + script.getName() + "] failed!",
+					ex);
+		}
+	}
+
+	private void initDatabase() {
+		logger.info("Initializing server data...");
+		executeScriptsFrom(getDirFromRelativePath(SCRIPT_DIR + appVersion));
+
+		securePasswords(); // encrypt the passwords
+	}
+
+	private File getDirFromRelativePath(String relativePath) {
+		String scriptDirPath = servletContext.getRealPath(relativePath);
+		File scriptDir = new File(scriptDirPath);
+		return scriptDir;
+	}
+
+	private void executeScriptsFrom(File scriptDir) {
+		if (!scriptDir.exists()) {
+			throw new GlusterRuntimeException("Script directory [" + scriptDir.getAbsolutePath() + "] doesn't exist!");
+		}
+		
+		List<File> scripts = Arrays.asList(scriptDir.listFiles());
+		if(scripts.size() == 0) {
+			throw new GlusterRuntimeException("Script directory [" + scriptDir.getAbsolutePath() + "] is empty!");
+		}
+		
+		Collections.sort(scripts);
+		for (File script : scripts) {
+			executeScript(script);
+		}
+	}
+
+	/**
+	 * Initializes the server database, if running for the first time.
+	 */
+	public synchronized void initServer() {
+		try {
+			String dbVersion = getDBVersion();
+			if (!appVersion.equals(dbVersion)) {
+				logger.info("App version [" + appVersion + "] differs from data version [" + dbVersion
+						+ "]. Trying to upgrade data...");
+				upgradeData(dbVersion, appVersion);
+			}
+		} catch (Exception ex) {
+			logger.info("No cluster created yet. DB version query failed with error [" + ex.getMessage() + "]", ex);
+			// Database not created yet. Create it!
+			initDatabase();
+		}
+	}
+
+	private void upgradeData(String fromVersion, String toVersion) {
+		executeScriptsFrom(getDirFromRelativePath(SCRIPT_DIR + fromVersion + "-" + toVersion));
+	}
+
+	private String getDBVersion() {
+		return (String) clusterDao.getSingleResultFromSQL("select version from version");
+	}
+}
diff --git a/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/InitializeDiskTask.java b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/InitializeDiskTask.java
new file mode 100644
index 00000000..45be980a
--- /dev/null
+++ b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/InitializeDiskTask.java
@@ -0,0 +1,198 @@
+/**
+ * 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 org.gluster.storage.management.gateway.tasks;
+
+import org.gluster.storage.management.core.constants.GlusterConstants;
+import org.gluster.storage.management.core.exceptions.ConnectionException;
+import org.gluster.storage.management.core.model.InitDiskStatusResponse;
+import org.gluster.storage.management.core.model.Status;
+import org.gluster.storage.management.core.model.TaskInfo;
+import org.gluster.storage.management.core.model.TaskStatus;
+import org.gluster.storage.management.core.model.InitDiskStatusResponse.FORMAT_STATUS;
+import org.gluster.storage.management.core.model.TaskInfo.TASK_TYPE;
+import org.gluster.storage.management.gateway.services.ClusterService;
+import org.gluster.storage.management.gateway.utils.ServerUtil;
+import org.springframework.context.ApplicationContext;
+import org.springframework.web.context.ContextLoader;
+
+import com.sun.jersey.core.util.Base64;
+
+public class InitializeDiskTask extends Task {
+
+	private static final String INITIALIZE_DISK_SCRIPT = "format_device.py";
+	private static final String INITIALIZE_DISK_STATUS_SCRIPT = "get_format_device_status.py";
+	
+	private String serverName;
+	private String diskName;
+	private String fsType;
+	private String mountPoint;
+	private ServerUtil serverUtil;
+
+	public InitializeDiskTask(ClusterService clusterService, String clusterName, String serverName, String diskName,
+			String fsType, String mountPoint) {
+		// Reference contains "Server:disk"
+		super(clusterService, clusterName, TASK_TYPE.DISK_FORMAT, serverName + ":" + diskName, "Initialize disk "
+				+ serverName + ":" + diskName, false, false, false);
+
+		setServerName(serverName);
+		setDiskName(diskName);
+		setFsType(fsType);
+		setMountpoint(mountPoint);
+		taskInfo.setName(getId());
+		init();
+	}
+
+	public InitializeDiskTask(ClusterService clusterService, String clusterName, TaskInfo info) {
+		super(clusterService, clusterName, info);
+		init();
+	}
+
+	private void init() {
+		ApplicationContext ctx = ContextLoader.getCurrentWebApplicationContext();
+		serverUtil = ctx.getBean(ServerUtil.class);
+	}
+	
+	@Override
+	public String getId() {
+		return new String(
+				Base64.encode(getClusterName() + "-" + taskInfo.getType() + "-" + serverName + ":" + diskName));
+	}
+
+	@Override
+	public void resume() {
+		getTaskInfo().setStatus(
+				new TaskStatus(new Status(Status.STATUS_CODE_FAILURE,
+						"Stop/Pause/Resume is not supported in Disk Initialization")));
+	}
+
+	@Override
+	public void stop() {
+		getTaskInfo().setStatus(
+				new TaskStatus(new Status(Status.STATUS_CODE_FAILURE,
+						"Stop/Pause/Resume is not supported in Disk Initialization")));
+	}
+
+	@Override
+	public void pause() {
+		getTaskInfo().setStatus(
+				new TaskStatus(new Status(Status.STATUS_CODE_FAILURE,
+						"Stop/Pause/Resume is not supported in Disk Initialization")));
+	}
+	
+	@Override
+	public void commit() {
+		// TODO Auto-generated method stub
+	}
+
+	@Override
+	public TASK_TYPE getType() {
+		return TASK_TYPE.DISK_FORMAT;
+	}
+
+	
+	@Override
+	public void start() {
+		try {
+			startInitializeDisk(serverName);
+		} catch(ConnectionException e) {
+			// online server might have gone offline.  update the failure status
+			getTaskInfo().setStatus(new TaskStatus(new Status(Status.STATUS_CODE_FAILURE, e.getMessage())));
+		}
+	}
+
+	private void startInitializeDisk(String serverName) {
+		String output = serverUtil.executeScriptOnServer(serverName, INITIALIZE_DISK_SCRIPT + " " + getFsType() + " \""
+				+ getMountpoint() + "\" " + getDiskName() );
+		TaskStatus taskStatus = new TaskStatus(new Status(Status.STATUS_CODE_RUNNING, output));
+		taskStatus.setPercentageSupported((getFsType().equals(GlusterConstants.FSTYPE_XFS)) ? false : true);
+		getTaskInfo().setStatus(taskStatus);
+	}
+
+	@Override
+	public TaskStatus checkStatus() {
+		
+		try {
+			return getInitializingDeviceStatus(serverName, getDiskName());
+		} catch(ConnectionException e) {
+			// online server might have gone offline. update the failure status
+			return new TaskStatus(new Status(Status.STATUS_CODE_FAILURE, e.getMessage()));
+		}
+	}
+	
+	private TaskStatus getInitializingDeviceStatus(String serverName, String diskName) {
+		InitDiskStatusResponse initDiskStatusResponse;
+		TaskStatus taskStatus = new TaskStatus();
+		
+		try {
+			initDiskStatusResponse = serverUtil.executeScriptOnServer(serverName, INITIALIZE_DISK_STATUS_SCRIPT + " "
+				+ diskName, InitDiskStatusResponse.class);
+		} catch(RuntimeException e) {
+			taskStatus.setCode(Status.STATUS_CODE_FAILURE);
+			taskStatus.setMessage(e.getMessage());
+			throw e;
+		}
+
+		if (initDiskStatusResponse.getFormatStatus() == FORMAT_STATUS.COMPLETED) {
+			taskStatus.setCode(Status.STATUS_CODE_SUCCESS);
+		} else if (initDiskStatusResponse.getFormatStatus() == FORMAT_STATUS.IN_PROGRESS) {
+			taskStatus.setCode(Status.STATUS_CODE_RUNNING);
+			taskStatus.setPercentCompleted(Math.round(initDiskStatusResponse.getCompletedBlocks()
+					/ initDiskStatusResponse.getTotalBlocks() * 100));
+		} else if(initDiskStatusResponse.getFormatStatus() == FORMAT_STATUS.NOT_RUNNING) {
+			taskStatus.setCode(Status.STATUS_CODE_FAILURE);
+		}
+		
+		taskStatus.setMessage(initDiskStatusResponse.getMessage());
+		return taskStatus;
+	}
+	
+	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;
+	}
+
+	public void setFsType(String fsType) {
+		this.fsType = fsType;
+	}
+
+	public String getFsType() {
+		return fsType;
+	}
+	
+	public void setMountpoint(String deviceMountPoint) {
+		this.mountPoint = deviceMountPoint;
+	}
+	
+	public String getMountpoint() {
+		return mountPoint;
+	}
+}
diff --git a/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/MigrateBrickTask.java b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/MigrateBrickTask.java
new file mode 100644
index 00000000..8a31f9a9
--- /dev/null
+++ b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/MigrateBrickTask.java
@@ -0,0 +1,220 @@
+/**
+ * MigrateDiskTask.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 org.gluster.storage.management.gateway.tasks;
+
+import org.gluster.storage.management.core.exceptions.ConnectionException;
+import org.gluster.storage.management.core.exceptions.GlusterRuntimeException;
+import org.gluster.storage.management.core.model.Status;
+import org.gluster.storage.management.core.model.TaskStatus;
+import org.gluster.storage.management.core.model.TaskInfo.TASK_TYPE;
+import org.gluster.storage.management.gateway.services.ClusterService;
+import org.gluster.storage.management.gateway.services.GlusterInterfaceService;
+import org.gluster.storage.management.gateway.utils.ServerUtil;
+import org.springframework.context.ApplicationContext;
+import org.springframework.web.context.ContextLoader;
+
+import com.sun.jersey.core.util.Base64;
+
+public class MigrateBrickTask extends Task {
+
+	private String fromBrick;
+	private String toBrick;
+	private Boolean autoCommit;
+	private GlusterInterfaceService glusterInterface;
+	protected ServerUtil serverUtil;
+
+	public String getFromBrick() {
+		return fromBrick;
+	}
+
+	public void setFromBrick(String fromBrick) {
+		this.fromBrick = fromBrick;
+	}
+
+	public String getToBrick() {
+		return toBrick;
+	}
+
+	public void setToBrick(String toBrick) {
+		this.toBrick = toBrick;
+	}
+
+	public Boolean getAutoCommit() {
+		return autoCommit;
+	}
+
+	public void setAutoCommit(Boolean autoCommit) {
+		this.autoCommit = autoCommit;
+	}
+
+	public MigrateBrickTask(ClusterService clusterService, String clusterName, String volumeName, String fromBrick,
+			String toBrick) {
+		super(clusterService, clusterName, TASK_TYPE.BRICK_MIGRATE, volumeName + "#" + fromBrick + "#" + toBrick,
+				"Brick Migration on volume [" + volumeName + "] from [" + fromBrick + "] to [" + toBrick + "]", true,
+				true, true);
+		setFromBrick(fromBrick);
+		setToBrick(toBrick);
+		taskInfo.setName(getId());
+		init();
+	}
+	
+	private void init() {
+		ApplicationContext ctx = ContextLoader.getCurrentWebApplicationContext();
+		glusterInterface = ctx.getBean(GlusterInterfaceService.class);
+		serverUtil = ctx.getBean(ServerUtil.class);
+	}
+
+	@Override
+	public String getId() {
+		return new String(Base64.encode(clusterName + "-" + taskInfo.getType() + "-" + taskInfo.getReference() + "-" + fromBrick + "-"
+				+ toBrick));
+	}
+
+	@Override
+	public void start() {
+		try {
+			startMigration(getOnlineServer().getName());
+		} catch (Exception e) {
+			// check if online server has gone offline. If yes, try again one more time.
+			if (e instanceof ConnectionException || serverUtil.isServerOnline(getOnlineServer()) == false) {
+				// online server might have gone Offline. try with a new one.
+				startMigration(getNewOnlineServer().getName());
+			} else {
+				throw new GlusterRuntimeException(e.getMessage());
+			}
+		}
+	}
+
+	private void startMigration(String onlineServerName) {
+		String volumeName = getTaskInfo().getReference().split("#")[0];
+		glusterInterface.startBrickMigration(onlineServerName, volumeName, getFromBrick(), getToBrick());
+		getTaskInfo().setStatus(new TaskStatus(new Status(Status.STATUS_CODE_RUNNING, "Brick Migration Started.")));
+	}
+
+	@Override
+	public void pause() {
+		try {
+			pauseMigration(getOnlineServer().getName());
+		} catch (Exception e) {
+			// check if online server has gone offline. If yes, try again one more time.
+			if (e instanceof ConnectionException || serverUtil.isServerOnline(getOnlineServer()) == false) {
+				// online server might have gone offline. try with a new one.
+				pauseMigration(getNewOnlineServer().getName());
+			} else {
+				throw new GlusterRuntimeException(e.getMessage());
+			}
+		}
+	}
+
+	private void pauseMigration(String onlineServer) {
+		String volumeName = getTaskInfo().getReference().split("#")[0];
+		glusterInterface.pauseBrickMigration(onlineServer, volumeName, getFromBrick(), getToBrick());
+		TaskStatus taskStatus = new TaskStatus();
+		taskStatus.setCode(Status.STATUS_CODE_PAUSE);
+		taskStatus.setMessage("Brick Migration Paused");
+		getTaskInfo().setStatus(taskStatus);
+	}
+
+	@Override
+	public void resume() {
+		start();
+	}
+
+	@Override
+	public void commit() {
+		try {
+			commitMigration(getOnlineServer().getName());
+		} catch (Exception e) {
+			// check if online server has gone offline. If yes, try again one more time.
+			if (e instanceof ConnectionException || serverUtil.isServerOnline(getOnlineServer()) == false) {
+				// online server might have gone offline. try with a new one.
+				commitMigration(getNewOnlineServer().getName());
+			} else {
+				throw new GlusterRuntimeException(e.getMessage());
+			}
+		}
+	}
+	
+	private void commitMigration(String serverName) {
+		String volumeName = getTaskInfo().getReference().split("#")[0];
+		glusterInterface.commitBrickMigration(serverName, volumeName, getFromBrick(), getToBrick());
+		TaskStatus taskStatus = new TaskStatus();
+		taskStatus.setCode(Status.STATUS_CODE_SUCCESS);
+		taskStatus.setMessage("Brick Migration Committed.");
+		getTaskInfo().setStatus(taskStatus);
+	}
+
+	@Override
+	public void stop() {
+		try {
+			stopMigration(getOnlineServer().getName());
+		} catch (Exception e) {
+			// check if online server has gone offline. If yes, try again one more time.
+			if (e instanceof ConnectionException || serverUtil.isServerOnline(getOnlineServer()) == false) {
+				// online server might have gone offline. try with a new one.
+				stopMigration(getNewOnlineServer().getName());
+			} else {
+				throw new GlusterRuntimeException(e.getMessage());
+			}
+		}
+	}
+
+	private void stopMigration(String serverName) {
+		String volumeName = getTaskInfo().getReference().split("#")[0];
+		glusterInterface.stopBrickMigration(serverName, volumeName, getFromBrick(), getToBrick());
+		TaskStatus taskStatus = new TaskStatus();
+		taskStatus.setCode(Status.STATUS_CODE_SUCCESS);
+		taskStatus.setMessage("Brick Migration Stopped");
+		getTaskInfo().setStatus(taskStatus);
+	}
+
+	@Override
+	public TaskStatus checkStatus() {
+		try {
+			return checkMigrationStatus(getOnlineServer().getName());
+		} catch (Exception e) {
+			// check if online server has gone offline. If yes, try again one more time.
+			if (e instanceof ConnectionException || serverUtil.isServerOnline(getOnlineServer()) == false) {
+				// online server might have gone offline. try with a new one.
+				return checkMigrationStatus(getNewOnlineServer().getName());
+			} 
+		}
+		return null;
+	}
+	
+	private TaskStatus checkMigrationStatus(String serverName) {
+		// For committed task, status command (CLI) is invalid, just return current status
+		if (taskInfo.getStatus().getCode() == Status.STATUS_CODE_SUCCESS) {
+			return taskInfo.getStatus();
+		}
+
+		String volumeName = getTaskInfo().getReference().split("#")[0];
+		TaskStatus taskStatus = glusterInterface.checkBrickMigrationStatus(serverName, volumeName, getFromBrick(),
+				getToBrick());
+		if (autoCommit && taskStatus.isCommitPending()) {
+			commitMigration(serverName);
+			return taskInfo.getStatus(); // return the committed status
+		}
+
+		taskInfo.setStatus(taskStatus); // Update the task status
+		return taskStatus;
+	}
+}
diff --git a/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/RebalanceVolumeTask.java b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/RebalanceVolumeTask.java
new file mode 100644
index 00000000..288179e9
--- /dev/null
+++ b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/RebalanceVolumeTask.java
@@ -0,0 +1,141 @@
+/**
+ * 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 org.gluster.storage.management.gateway.tasks;
+
+import org.gluster.storage.management.core.exceptions.ConnectionException;
+import org.gluster.storage.management.core.exceptions.GlusterRuntimeException;
+import org.gluster.storage.management.core.model.Status;
+import org.gluster.storage.management.core.model.TaskStatus;
+import org.gluster.storage.management.core.model.TaskInfo.TASK_TYPE;
+import org.gluster.storage.management.gateway.services.ClusterService;
+import org.gluster.storage.management.gateway.services.GlusterInterfaceService;
+import org.gluster.storage.management.gateway.utils.ServerUtil;
+import org.springframework.context.ApplicationContext;
+import org.springframework.web.context.ContextLoader;
+
+import com.sun.jersey.core.util.Base64;
+
+public class RebalanceVolumeTask extends Task {
+
+	private String layout;
+	private String serverName;
+	private ServerUtil serverUtil;
+	private GlusterInterfaceService glusterUtil;
+
+	public RebalanceVolumeTask(ClusterService clusterService, String clusterName, String volumeName, String layout) {
+		super(clusterService, clusterName, TASK_TYPE.VOLUME_REBALANCE, volumeName, "Volume " + volumeName
+				+ " Rebalance", false, true, false);
+		setLayout(layout);
+		taskInfo.setName(getId());
+		init();
+	}
+	
+	private void init() {
+		ApplicationContext ctx = ContextLoader.getCurrentWebApplicationContext();
+		serverUtil = ctx.getBean(ServerUtil.class);
+		glusterUtil = ctx.getBean(GlusterInterfaceService.class);
+	}
+
+	@Override
+	public String getId() {
+		return new String(Base64.encode(getClusterName() + "-" + taskInfo.getType() + "-" + taskInfo.getReference()));
+	}
+
+	@Override
+	public void start() {
+		try {
+			serverName = getOnlineServer().getName();
+			startRebalance(serverName);
+		} catch (Exception e) {
+			// check if online server has gone offline. If yes, try again one more time.
+			if (e instanceof ConnectionException || serverUtil.isServerOnline(getOnlineServer()) == false) {
+				// online server might have gone offline. try with a new one
+				serverName = getNewOnlineServer().getName();
+				startRebalance(serverName);
+			} else {
+				throw new GlusterRuntimeException(e.getMessage());
+			}
+		}
+	}
+
+	private void startRebalance(String serverName) {
+		String command = "gluster volume rebalance " + getTaskInfo().getReference() + " " + getLayout() + " start";
+		String output = serverUtil.executeOnServer(serverName, command);
+		getTaskInfo().setStatus(new TaskStatus(new Status(Status.STATUS_CODE_RUNNING, output)));
+	}
+
+	@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 {
+			glusterUtil.stopRebalance(serverName, getTaskInfo().getReference());
+		} catch (Exception e) {
+			// check if online server has gone offline. If yes, try again one more time.
+			if (e instanceof ConnectionException || serverUtil.isServerOnline(getOnlineServer()) == false) {
+				// online server might have gone offline. update the failure status
+				getTaskInfo().setStatus(new TaskStatus(new Status(Status.STATUS_CODE_FAILURE, e.getMessage())));
+			} else {
+				throw new GlusterRuntimeException(e.getMessage());
+			}
+		}
+	}
+
+	@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 glusterUtil.checkRebalanceStatus(serverName, getTaskInfo().getReference());
+		} catch (Exception e) {
+			// check if online server has gone offline. If yes, try again one more time.
+			if (e instanceof ConnectionException || serverUtil.isServerOnline(getOnlineServer()) == false) {
+				// online server might have gone offline. update the failure status
+				getTaskInfo().setStatus(new TaskStatus(new Status(Status.STATUS_CODE_FAILURE, e.getMessage())));
+				return getTaskInfo().getStatus();
+			}
+		}
+		return null;
+	}
+	
+	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/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/ServerSyncTask.java b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/ServerSyncTask.java
new file mode 100644
index 00000000..c3073d97
--- /dev/null
+++ b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/ServerSyncTask.java
@@ -0,0 +1,168 @@
+/**
+ * ServerDiscoveryTask.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 org.gluster.storage.management.gateway.tasks;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.log4j.Logger;
+import org.gluster.storage.management.core.constants.CoreConstants;
+import org.gluster.storage.management.core.constants.GlusterConstants;
+import org.gluster.storage.management.core.model.GlusterServer;
+import org.gluster.storage.management.core.utils.GlusterCoreUtil;
+import org.gluster.storage.management.core.utils.ProcessResult;
+import org.gluster.storage.management.gateway.data.ClusterInfo;
+import org.gluster.storage.management.gateway.data.PersistenceDao;
+import org.gluster.storage.management.gateway.data.ServerInfo;
+import org.gluster.storage.management.gateway.services.ClusterService;
+import org.gluster.storage.management.gateway.services.DiscoveredServerService;
+import org.gluster.storage.management.gateway.services.GlusterServerService;
+import org.gluster.storage.management.gateway.utils.ServerUtil;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+
+/**
+ * Task for syncing server details. This performs two things: <br>
+ * 1. Auto-discovery of servers eligible to be added to the Gluster cluster. <br>
+ * 2. Syncing of cluster-server mapping with actual servers of the cluster. This mapping can go out of sync if user
+ * adds/removes servers manually using the CLI.
+ */
+@Component
+public class ServerSyncTask {
+	private static final String SCRIPT_NAME_SFX = "-discover-servers.py";
+	
+	@Autowired
+	private ServerUtil serverUtil;
+	
+	@Autowired
+	private DiscoveredServerService discoveredServersService;
+	
+	@Autowired
+	private GlusterServerService glusterServerService;
+
+	@Autowired
+	private String discoveryMechanism;
+	
+	@Autowired
+	private ClusterService clusterService;
+	
+	@Autowired
+	private PersistenceDao<ClusterInfo> clusterDao;
+	
+	private static final Logger logger = Logger.getLogger(ServerSyncTask.class);
+
+	public void perform() {
+		discoverServers();
+		syncClusterServerMapping();
+	}
+	
+	private void syncClusterServerMapping() {
+		List<ClusterInfo> clusters = clusterService.getAllClusters();
+		for(ClusterInfo cluster : clusters) {
+			try {
+				List<ServerInfo> servers = cluster.getServers();
+				if(servers.isEmpty()) {
+					logger.info("Cluster [" + cluster.getName() + "] is empty, nothing to sync!");
+					continue;
+				}
+				List<GlusterServer> actualServers = glusterServerService.getGlusterServers(cluster.getName(), false,
+						null, null);
+				updateRemovedServers(cluster, servers, actualServers);
+				updateAddedServers(cluster, servers, actualServers);
+			} catch(Exception e) {
+				// log error and continue with next cluster
+				logger.error("Couldn't sync cluster-server mapping for cluster [" + cluster.getName() + "]!", e);
+				continue;
+			}
+		}
+	}
+
+	private void updateAddedServers(ClusterInfo cluster, List<ServerInfo> servers, List<GlusterServer> actualServers) {
+		List<String> addedServers = findAddedServers(cluster.getName(), servers, actualServers);
+		for(String addedServer : addedServers) {
+			clusterService.mapServerToCluster(cluster.getName(), addedServer);
+		}
+	}
+
+	private void updateRemovedServers(ClusterInfo cluster, List<ServerInfo> servers, List<GlusterServer> actualServers) {
+		List<String> removedServers = findRemovedServers(servers, actualServers);
+		for(String removedServer : removedServers) {
+			clusterService.unmapServerFromCluster(cluster.getName(), removedServer);
+		}
+	}
+	
+	private List<String> findRemovedServers(List<ServerInfo> servers, List<GlusterServer> actualServers) {
+		List<String> removedServers = new ArrayList<String>();
+		
+		for(ServerInfo server : servers) {
+			if (!GlusterCoreUtil.containsEntityWithName(actualServers, server.getName(), true)) {
+				removedServers.add(server.getName());
+			}
+		}
+		return removedServers;
+	}
+	
+	private List<String> findAddedServers(String clusterName, List<ServerInfo> servers, List<GlusterServer> actualServers) {
+		List<String> addedServers = new ArrayList<String>();
+		for(GlusterServer actualServer : actualServers) {
+			if(!serverExists(servers, actualServer.getName())) {
+				addedServers.add(actualServer.getName());
+			}
+		}
+		return addedServers;
+	}
+
+	private boolean serverExists(List<ServerInfo> servers, String name) {
+		for(ServerInfo server : servers) {
+			if(server.getName().equalsIgnoreCase(name)) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	@SuppressWarnings("unchecked")
+	private void discoverServers() {
+		if(discoveryMechanism.equals(GlusterConstants.NONE)) {
+			return;
+		}
+		
+		List<String> serverNameList = new ArrayList<String>();
+		
+		ProcessResult result = serverUtil.executeGlusterScript(true, discoveryMechanism + SCRIPT_NAME_SFX, new ArrayList<String>());
+		if(result.isSuccess()) {
+			List<String> existingServers = clusterDao.findBySQL("select name from server_info");
+			String serverNames = result.getOutput();
+			String[] parts = serverNames.split(CoreConstants.NEWLINE);
+			for(String serverName : parts) {
+				// The server discovery mechanism will return every server that has not been "peer probed". However we
+				// need to filter out those servers that are the "first" server of a new cluster, and hence are still
+				// not peer probed.
+				if(!existingServers.contains(serverName)) {
+					serverNameList.add(serverName);
+				}
+			}
+		}
+		
+		discoveredServersService.setDiscoveredServerNames(serverNameList);
+	}
+}
\ No newline at end of file
diff --git a/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/Task.java b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/Task.java
new file mode 100644
index 00000000..0fee3c2e
--- /dev/null
+++ b/src/org.gluster.storage.management.gateway/src/org/gluster/storage/management/gateway/tasks/Task.java
@@ -0,0 +1,113 @@
+/**
+ * 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 org.gluster.storage.management.gateway.tasks;
+
+import org.gluster.storage.management.core.model.GlusterServer;
+import org.gluster.storage.management.core.model.TaskInfo;
+import org.gluster.storage.management.core.model.TaskStatus;
+import org.gluster.storage.management.core.model.TaskInfo.TASK_TYPE;
+import org.gluster.storage.management.gateway.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.setPauseSupported(canPause);
+		taskInfo.setStopSupported(canStop);
+		taskInfo.setCommitSupported(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();
+}