refactor zk client.

escheduler-api/src/main/java/cn/escheduler/api/service/MonitorService.java

@@ -65,7 +65,7 @@ public class MonitorService extends BaseService{
 
     Map<String, Object> result = new HashMap<>(5);
 
-    List<MasterServer> masterServers = getServerList(true);
+    List<MasterServer> masterServers = getServerListFromZK(true);
     result.put(Constants.DATA_LIST, masterServers);
     putMsg(result,Status.SUCCESS);
 
@@ -99,7 +99,7 @@ public class MonitorService extends BaseService{
   public Map<String,Object> queryWorker(User loginUser) {
 
     Map<String, Object> result = new HashMap<>(5);
-    List<MasterServer> workerServers = getServerList(false);
+    List<MasterServer> workerServers = getServerListFromZK(false);
 
     result.put(Constants.DATA_LIST, workerServers);
     putMsg(result,Status.SUCCESS);
@@ -107,13 +107,13 @@ public class MonitorService extends BaseService{
     return result;
   }
 
-  private List<MasterServer> getServerList(boolean isMaster){
+  private List<MasterServer> getServerListFromZK(boolean isMaster){
     List<MasterServer> servers = new ArrayList<>();
     ZookeeperMonitor zookeeperMonitor = null;
     try{
       zookeeperMonitor = new ZookeeperMonitor();
       ZKNodeType zkNodeType = isMaster ? ZKNodeType.MASTER : ZKNodeType.WORKER;
-      servers = zookeeperMonitor.getServers(zkNodeType);
+      servers = zookeeperMonitor.getServersList(zkNodeType);
     }catch (Exception e){
       throw e;
     }finally {

escheduler-api/src/main/java/cn/escheduler/api/utils/ZookeeperMonitor.java

@@ -40,7 +40,7 @@ public class ZookeeperMonitor extends AbstractZKClient{
 	 * @return
 	 */
 	public List<MasterServer> getMasterServers(){
-	    return getServers(ZKNodeType.MASTER);
+	    return getServersList(ZKNodeType.MASTER);
 	}
 
 	/**
@@ -48,7 +48,7 @@ public class ZookeeperMonitor extends AbstractZKClient{
 	 * @return
 	 */
 	public List<MasterServer> getWorkerServers(){
-	    return getServers(ZKNodeType.WORKER);
+	    return getServersList(ZKNodeType.WORKER);
 	}
 
 	private static List<ZookeeperRecord> zookeeperInfoList(String zookeeperServers) {

escheduler-common/src/main/java/cn/escheduler/common/zk/AbstractZKClient.java

@@ -20,7 +20,6 @@ import cn.escheduler.common.Constants;
 import cn.escheduler.common.IStoppable;
 import cn.escheduler.common.enums.ZKNodeType;
 import cn.escheduler.common.model.MasterServer;
-import cn.escheduler.common.utils.CollectionUtils;
 import cn.escheduler.common.utils.DateUtils;
 import cn.escheduler.common.utils.OSUtils;
 import cn.escheduler.common.utils.ResInfo;
@@ -223,28 +222,68 @@ public abstract class AbstractZKClient {
         }
 	}
 
+
+	/**
+	 * create zookeeper path according the zk node type.
+	 * @param zkNodeType
+	 * @return
+	 * @throws Exception
+	 */
+	private String createZNodePath(ZKNodeType zkNodeType) throws Exception {
+		// specify the format of stored data in ZK nodes
+		String heartbeatZKInfo = ResInfo.getHeartBeatInfo(new Date());
+		// create temporary sequence nodes for master znode
+		String parentPath = getZNodeParentPath(zkNodeType);
+		String serverPathPrefix = parentPath + "/" + OSUtils.getHost();
+		String registerPath = zkClient.create().withMode(CreateMode.EPHEMERAL_SEQUENTIAL).forPath(
+				serverPathPrefix + "_", heartbeatZKInfo.getBytes());
+		logger.info("register {} node {} success" , zkNodeType.toString(), registerPath);
+		return registerPath;
+	}
+
+	/**
+	 * register server,  if server already exists, return null.
+	 * @param zkNodeType
+	 * @return register server path in zookeeper
+	 */
+	public String registerServer(ZKNodeType zkNodeType) throws Exception {
+		String registerPath = null;
+		String host = OSUtils.getHost();
+		if(checkZKNodeExists(host, zkNodeType)){
+			logger.error("register failure , {} server already started on host : {}" ,
+					zkNodeType.toString(), host);
+			return registerPath;
+		}
+		registerPath = createZNodePath(ZKNodeType.MASTER);
+
+		// handle dead server
+		handleDeadServer(registerPath, zkNodeType, Constants.DELETE_ZK_OP);
+
+		return registerPath;
+	}
+
 	/**
 	 * opType(add): if find dead server , then add to zk deadServerPath
 	 * opType(delete): delete path from zk
 	 *
 	 * @param zNode   		  node path
-	 * @param serverType	  master or worker prefix
+	 * @param zkNodeType	  master or worker
 	 * @param opType		  delete or add
 	 * @throws Exception
 	 */
-	public void handleDeadServer(String zNode, String serverType, String opType) throws Exception {
+	public void handleDeadServer(String zNode, ZKNodeType zkNodeType, String opType) throws Exception {
 		//ip_sequenceno
 		String[] zNodesPath = zNode.split("\\/");
 		String ipSeqNo = zNodesPath[zNodesPath.length - 1];
 
-		String type = serverType.equals(MASTER_PREFIX) ? MASTER_PREFIX : WORKER_PREFIX;
+		String type = (zkNodeType == ZKNodeType.MASTER) ? MASTER_PREFIX : WORKER_PREFIX;
 
 
 		//check server restart, if restart , dead server path in zk should be delete
 		if(opType.equals(DELETE_ZK_OP)){
 			String[] ipAndSeqNo = ipSeqNo.split(UNDERLINE);
 			String ip = ipAndSeqNo[0];
-			removeDeadServerByHost(ip, serverType);
+			removeDeadServerByHost(ip, type);
 
 		}else if(opType.equals(ADD_ZK_OP)){
 			String deadServerPath = deadServerZNodeParentPath + SINGLE_SLASH + type + UNDERLINE + ipSeqNo;
@@ -253,7 +292,8 @@ public abstract class AbstractZKClient {
 
 				zkClient.create().forPath(deadServerPath,(type + UNDERLINE + ipSeqNo).getBytes());
 
-				logger.info("{} server dead , and {} added to zk dead server path success" , serverType, zNode);
+				logger.info("{} server dead , and {} added to zk dead server path success" ,
+						zkNodeType.toString(), zNode);
 			}
 		}
 
@@ -314,8 +354,8 @@ public abstract class AbstractZKClient {
 	 * @param zkNodeType
 	 * @return
 	 */
-	public List<MasterServer> getServers(ZKNodeType zkNodeType){
+	public List<MasterServer> getServersList(ZKNodeType zkNodeType){
-		Map<String, String> masterMap = getServerList(zkNodeType);
+		Map<String, String> masterMap = getServerMaps(zkNodeType);
 		String parentPath = getZNodeParentPath(zkNodeType);
 
 		List<MasterServer> masterServers = new ArrayList<>();
@@ -332,7 +372,7 @@ public abstract class AbstractZKClient {
 	 * result : {host : resource info}
 	 * @return
 	 */
-	public Map<String, String> getServerList(ZKNodeType zkNodeType){
+	public Map<String, String> getServerMaps(ZKNodeType zkNodeType){
 
 		Map<String, String> masterMap = new HashMap<>();
 		try {
@@ -363,7 +403,7 @@ public abstract class AbstractZKClient {
 					host, zkNodeType.toString());
 			return false;
 		}
-		Map<String, String> serverMaps = getServerList(zkNodeType);
+		Map<String, String> serverMaps = getServerMaps(zkNodeType);
 		for(String hostKey : serverMaps.keySet()){
 			if(hostKey.startsWith(host)){
 				return true;
@@ -497,7 +537,39 @@ public abstract class AbstractZKClient {
 		}
 	}
 
-	@Override
+	/**
+	 * server self dead, stop all threads
+	 * @param serverHost
+	 * @param zkNodeType
+	 */
+	protected boolean checkServerSelfDead(String serverHost, ZKNodeType zkNodeType) {
+		if (serverHost.equals(OSUtils.getHost())) {
+			logger.error("{} server({}) of myself dead , stopping...",
+					zkNodeType.toString(), serverHost);
+			stoppable.stop(String.format(" {} server {} of myself dead , stopping...",
+					zkNodeType.toString(), serverHost));
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 *  get host ip, string format: masterParentPath/ip_000001/value
+	 * @param path
+	 * @return
+	 */
+	protected String getHostByEventDataPath(String path) {
+		int  startIndex = path.lastIndexOf("/")+1;
+		int endIndex = 	path.lastIndexOf("_");
+
+		if(startIndex >= endIndex){
+			logger.error("parse ip error");
+			return "";
+		}
+		return path.substring(startIndex, endIndex);
+	}
+
+		@Override
 	public String toString() {
 		return "AbstractZKClient{" +
 				"zkClient=" + zkClient +

escheduler-server/src/main/java/cn/escheduler/server/master/MasterServer.java

@@ -119,8 +119,6 @@ public class MasterServer implements CommandLineRunner, IStoppable {
 
     public MasterServer(ProcessDao processDao){
         zkMasterClient = ZKMasterClient.getZKMasterClient(processDao);
-        this.serverDao = zkMasterClient.getServerDao();
-        this.alertDao = zkMasterClient.getAlertDao();
     }
     public void run(ProcessDao processDao){
 
@@ -128,6 +126,11 @@ public class MasterServer implements CommandLineRunner, IStoppable {
         heartBeatInterval = conf.getInt(Constants.MASTER_HEARTBEAT_INTERVAL,
                 Constants.defaultMasterHeartbeatInterval);
 
+        // master exec thread pool num
+        int masterExecThreadNum = conf.getInt(Constants.MASTER_EXEC_THREADS,
+                Constants.defaultMasterExecThreadNum);
+
+
         heartbeatMasterService = ThreadUtils.newDaemonThreadScheduledExecutor("Master-Main-Thread",Constants.defaulMasterHeartbeatThreadNum);
 
         // heartbeat thread implement
@@ -140,10 +143,6 @@ public class MasterServer implements CommandLineRunner, IStoppable {
         heartbeatMasterService.
                 scheduleAtFixedRate(heartBeatThread, 5, heartBeatInterval, TimeUnit.SECONDS);
 
-        // master exec thread pool num
-        int masterExecThreadNum = conf.getInt(Constants.MASTER_EXEC_THREADS,
-                Constants.defaultMasterExecThreadNum);
-
         // master scheduler thread
         MasterSchedulerThread masterSchedulerThread = new MasterSchedulerThread(
                 zkMasterClient,
@@ -154,6 +153,8 @@ public class MasterServer implements CommandLineRunner, IStoppable {
         masterSchedulerService.execute(masterSchedulerThread);
 
         // start QuartzExecutors
+        // TODO...
+        // what system should do if exception
         try {
             ProcessScheduleJob.init(processDao);
             QuartzExecutors.getInstance().start();
@@ -173,13 +174,11 @@ public class MasterServer implements CommandLineRunner, IStoppable {
         Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
             @Override
             public void run() {
-                String host = OSUtils.getHost();
-                // clear master table register info
-                serverDao.deleteMaster(host);
                 logger.info("master server stopped");
                 if (zkMasterClient.getActiveMasterNum() <= 1) {
                     for (int i = 0; i < Constants.ESCHEDULER_WARN_TIMES_FAILOVER;i++) {
-                        alertDao.sendServerStopedAlert(1, host, "Master-Server");
+                        zkMasterClient.getAlertDao().sendServerStopedAlert(
+                                1, OSUtils.getHost(), "Master-Server");
                     }
                 }
             }

escheduler-server/src/main/java/cn/escheduler/server/zk/ZKMasterClient.java

@@ -20,8 +20,6 @@ import cn.escheduler.common.Constants;
 import cn.escheduler.common.enums.ExecutionStatus;
 import cn.escheduler.common.enums.ZKNodeType;
 import cn.escheduler.common.model.MasterServer;
-import cn.escheduler.common.utils.CollectionUtils;
-import cn.escheduler.common.utils.OSUtils;
 import cn.escheduler.common.zk.AbstractZKClient;
 import cn.escheduler.dao.AlertDao;
 import cn.escheduler.dao.DaoFactory;
@@ -29,8 +27,6 @@ import cn.escheduler.dao.ProcessDao;
 import cn.escheduler.dao.ServerDao;
 import cn.escheduler.dao.model.ProcessInstance;
 import cn.escheduler.dao.model.TaskInstance;
-import cn.escheduler.dao.model.WorkerServer;
-import cn.escheduler.common.utils.ResInfo;
 import cn.escheduler.server.utils.ProcessUtils;
 import org.apache.commons.lang.StringUtils;
 import org.apache.curator.framework.CuratorFramework;
@@ -39,7 +35,6 @@ import org.apache.curator.framework.recipes.cache.PathChildrenCacheEvent;
 import org.apache.curator.framework.recipes.cache.PathChildrenCacheListener;
 import org.apache.curator.framework.recipes.locks.InterProcessMutex;
 import org.apache.curator.utils.ThreadUtils;
-import org.apache.zookeeper.CreateMode;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -68,6 +63,7 @@ public class ZKMasterClient extends AbstractZKClient {
 	 *  master database access
 	 */
 	private ServerDao serverDao = null;
+
 	/**
 	 *  alert database access
 	 */
@@ -77,9 +73,6 @@ public class ZKMasterClient extends AbstractZKClient {
 	 */
 	private ProcessDao processDao;
 
-
-	private Date createTime = null;
-
 	/**
 	 *  zkMasterClient
 	 */
@@ -131,7 +124,7 @@ public class ZKMasterClient extends AbstractZKClient {
 			this.listenerWorker();
 
 			// register master
-			this.registMaster();
+			this.registerMaster();
 
 			// check if fault tolerance is required，failure and tolerance
 			if (getActiveMasterNum() == 1) {
@@ -157,15 +150,6 @@ public class ZKMasterClient extends AbstractZKClient {
 		this.alertDao = DaoFactory.getDaoInstance(AlertDao.class);
 		this.processDao = DaoFactory.getDaoInstance(ProcessDao.class);
 	}
-
-	/**
-	 *  get maste dao
-	 * @return
-	 */
-	public ServerDao getServerDao(){
-		return serverDao;
-	}
-
 	/**
 	 * get alert dao
 	 * @return
@@ -174,40 +158,24 @@ public class ZKMasterClient extends AbstractZKClient {
 		return alertDao;
 	}
 
+
+
+
 	/**
 	 *  register master znode
 	 */
-	public void registMaster(){
+	public void registerMaster(){
-
-		// get current date
-		Date now = new Date();
-		createTime = now ;
 		try {
-			String osHost = OSUtils.getHost();
+		    String serverPath = registerServer(ZKNodeType.MASTER);
-
+		    if(StringUtils.isEmpty(serverPath)){
-			// zookeeper node exists, cannot start a new one.
+		    	System.exit(-1);
-			if(checkZKNodeExists(osHost, ZKNodeType.MASTER)){
-				logger.error("register failure , master already started on host : {}" , osHost);
-				// exit system
-				System.exit(-1);
 			}
-			createMasterZNode(now);
-			logger.info("register master node {} success" , masterZNode);
-
-			// handle dead server
-			handleDeadServer(masterZNode, Constants.MASTER_PREFIX, Constants.DELETE_ZK_OP);
 		} catch (Exception e) {
 			logger.error("register master failure : "  + e.getMessage(),e);
+			System.exit(-1);
 		}
 	}
 
-	private void createMasterZNode(Date now) throws Exception {
-		// specify the format of stored data in ZK nodes
-		String heartbeatZKInfo = ResInfo.getHeartBeatInfo(now);
-		// create temporary sequence nodes for master znode
-		masterZNode = zkClient.create().withMode(CreateMode.EPHEMERAL_SEQUENTIAL).forPath(
-				masterZNodeParentPath + "/" + OSUtils.getHost() + "_", heartbeatZKInfo.getBytes());
-	}
 
 
 	/**
@@ -217,8 +185,6 @@ public class ZKMasterClient extends AbstractZKClient {
 		PathChildrenCache masterPc = new PathChildrenCache(zkClient, masterZNodeParentPath, true ,defaultThreadFactory);
 
 		try {
-			Date now = new Date();
-			createTime = now ;
 			masterPc.start();
 			masterPc.getListenable().addListener(new PathChildrenCacheListener() {
 				@Override
@@ -229,8 +195,11 @@ public class ZKMasterClient extends AbstractZKClient {
 							break;
 						case CHILD_REMOVED:
 							String path = event.getData().getPath();
-							logger.info("master node deleted : {}",event.getData().getPath());
+							String serverHost = getHostByEventDataPath(path);
-							removeMasterNode(path);
+							if(checkServerSelfDead(serverHost, ZKNodeType.MASTER)){
+								return;
+							}
+							removeZKNodePath(path, ZKNodeType.MASTER, true);
 							break;
 						case CHILD_UPDATED:
 							break;
@@ -242,46 +211,69 @@ public class ZKMasterClient extends AbstractZKClient {
 		}catch (Exception e){
 			logger.error("monitor master failed : " + e.getMessage(),e);
 		}
+}
 
-	}
+	private void removeZKNodePath(String path, ZKNodeType zkNodeType, boolean failover) {
-
+		logger.info("{} node deleted : {}", zkNodeType.toString(), path);
-	private void removeMasterNode(String path) {
+		InterProcessMutex mutex = null;
-		InterProcessMutex mutexLock = null;
 		try {
-			// handle dead server, add to zk dead server pth
+			String failoverPath = getFailoverLockPath(zkNodeType);
-			handleDeadServer(path, Constants.MASTER_PREFIX, Constants.ADD_ZK_OP);
+			// create a distributed lock
+			mutex = new InterProcessMutex(getZkClient(), failoverPath);
+			mutex.acquire();
 
-			if(masterZNode.equals(path)){
+			String serverHost = getHostByEventDataPath(path);
-				logger.error("master server({}) of myself dead , stopping...", path);
+			// handle dead server
-				stoppable.stop(String.format("master server(%s) of myself dead , stopping...", path));
+			handleDeadServer(path, zkNodeType, Constants.ADD_ZK_OP);
-				return;
+			//alert server down.
-			}
+			alertServerDown(serverHost, zkNodeType);
-
+			//failover server
-			// create a distributed lock, and the root node path of the lock space is /escheduler/lock/failover/master
+			if(failover){
-			String znodeLock = zkMasterClient.getMasterFailoverLockPath();
+				failoverServerWhenDown(serverHost, zkNodeType);
-			mutexLock = new InterProcessMutex(zkMasterClient.getZkClient(), znodeLock);
-			mutexLock.acquire();
-
-			String masterHost = getHostByEventDataPath(path);
-			for (int i = 0; i < Constants.ESCHEDULER_WARN_TIMES_FAILOVER;i++) {
-				alertDao.sendServerStopedAlert(1, masterHost, "Master-Server");
-			}
-			if(StringUtils.isNotEmpty(masterHost)){
-				failoverMaster(masterHost);
 			}
 		}catch (Exception e){
-			logger.error("master failover failed : " + e.getMessage(),e);
+			logger.error("{} server failover failed.", zkNodeType.toString());
-		}finally {
+			logger.error("failover exception : " + e.getMessage(),e);
-			if (mutexLock != null){
+		}
-				try {
+		finally {
-					mutexLock.release();
+			releaseMutex(mutex);
-				} catch (Exception e) {
-					logger.error("lock relase failed : " + e.getMessage(),e);
-				}
-			}
 		}
 	}
 
+	private void failoverServerWhenDown(String serverHost, ZKNodeType zkNodeType) throws Exception {
+	    if(StringUtils.isEmpty(serverHost)){
+	    	return ;
+		}
+		switch (zkNodeType){
+			case MASTER:
+				failoverMaster(serverHost);
+				break;
+			case WORKER:
+				failoverWorker(serverHost, true);
+			default:
+				break;
+		}
+	}
+
+	private String getFailoverLockPath(ZKNodeType zkNodeType){
+
+		switch (zkNodeType){
+			case MASTER:
+				return getMasterFailoverLockPath();
+			case WORKER:
+				return getWorkerFailoverLockPath();
+			default:
+				return "";
+		}
+	}
+
+	private void alertServerDown(String serverHost, ZKNodeType zkNodeType) {
+
+	    String serverType = zkNodeType.toString();
+		for (int i = 0; i < Constants.ESCHEDULER_WARN_TIMES_FAILOVER; i++) {
+			alertDao.sendServerStopedAlert(1, serverHost, serverType);
+		}
+	}
 
 	/**
 	 *  monitor worker
@@ -290,8 +282,6 @@ public class ZKMasterClient extends AbstractZKClient {
 
 		PathChildrenCache workerPc = new PathChildrenCache(zkClient,workerZNodeParentPath,true ,defaultThreadFactory);
 		try {
-			Date now = new Date();
-			createTime = now ;
 			workerPc.start();
 			workerPc.getListenable().addListener(new PathChildrenCacheListener() {
 				@Override
@@ -303,7 +293,7 @@ public class ZKMasterClient extends AbstractZKClient {
 						case CHILD_REMOVED:
 							String path = event.getData().getPath();
 							logger.info("node deleted : {}",event.getData().getPath());
-							removeZKNodePath(path);
+							removeZKNodePath(path, ZKNodeType.WORKER, true);
 							break;
 						default:
 							break;
@@ -315,33 +305,6 @@ public class ZKMasterClient extends AbstractZKClient {
 		}
 	}
 
-	private void removeZKNodePath(String path) {
-		InterProcessMutex mutex = null;
-		try {
-
-			// handle dead server
-			handleDeadServer(path, Constants.WORKER_PREFIX, Constants.ADD_ZK_OP);
-
-			// create a distributed lock
-			String znodeLock = getWorkerFailoverLockPath();
-			mutex = new InterProcessMutex(getZkClient(), znodeLock);
-			mutex.acquire();
-
-			String workerHost = getHostByEventDataPath(path);
-			for (int i = 0; i < Constants.ESCHEDULER_WARN_TIMES_FAILOVER;i++) {
-				alertDao.sendServerStopedAlert(1, workerHost, "Worker-Server");
-			}
-
-			if(StringUtils.isNotEmpty(workerHost)){
-				failoverWorker(workerHost, true);
-			}
-		}catch (Exception e){
-			logger.error("worker failover failed : " + e.getMessage(),e);
-		}
-		finally {
-		    releaseMutex(mutex);
-		}
-	}
 
 	/**
 	 *  get master znode
@@ -381,7 +344,7 @@ public class ZKMasterClient extends AbstractZKClient {
 	    	return false;
 		}
 	    Date workerServerStartDate = null;
-	    List<MasterServer> workerServers= getServers(ZKNodeType.WORKER);
+	    List<MasterServer> workerServers= getServersList(ZKNodeType.WORKER);
 	    for(MasterServer server : workerServers){
 	    	if(server.getHost().equals(taskInstance.getHost())){
 	    	    workerServerStartDate = server.getCreateTime();
@@ -444,24 +407,4 @@ public class ZKMasterClient extends AbstractZKClient {
 		logger.info("master failover end");
 	}
 
-	/**
-	 *  get host ip, string format: masterParentPath/ip_000001/value
-	 * @param path
-	 * @return
-	 */
-	private String getHostByEventDataPath(String path) {
-		int  startIndex = path.lastIndexOf("/")+1;
-		int endIndex = 	path.lastIndexOf("_");
-
-		if(startIndex >= endIndex){
-			logger.error("parse ip error");
-			return "";
-		}
-		return path.substring(startIndex, endIndex);
-	}
-
-
-
-
-
 }

escheduler-server/src/main/java/cn/escheduler/server/zk/ZKWorkerClient.java

@@ -18,12 +18,12 @@ package cn.escheduler.server.zk;
 
 import cn.escheduler.common.Constants;
 import cn.escheduler.common.enums.ZKNodeType;
-import cn.escheduler.common.utils.CollectionUtils;
 import cn.escheduler.common.utils.OSUtils;
 import cn.escheduler.common.zk.AbstractZKClient;
 import cn.escheduler.dao.DaoFactory;
 import cn.escheduler.dao.ServerDao;
 import cn.escheduler.common.utils.ResInfo;
+import org.apache.commons.lang.StringUtils;
 import org.apache.curator.framework.CuratorFramework;
 import org.apache.curator.framework.recipes.cache.PathChildrenCache;
 import org.apache.curator.framework.recipes.cache.PathChildrenCacheEvent;
@@ -34,7 +34,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.Date;
-import java.util.List;
 import java.util.concurrent.ThreadFactory;
 
 
@@ -130,21 +129,14 @@ public class ZKWorkerClient extends AbstractZKClient {
 	 *  register worker
 	 */
 	private void registWorker(){
-		// get current date
-		Date now = new Date();
-		createTime = now ;
 		try {
-			if(checkZKNodeExists(OSUtils.getHost(), ZKNodeType.WORKER)){
+			String serverPath = registerServer(ZKNodeType.WORKER);
-				logger.info("register failure , worker already started on : {}, please wait for a moment and try again" , OSUtils.getHost());
+			if(StringUtils.isEmpty(serverPath)){
 				System.exit(-1);
 			}
-
-			// create worker zknode
-            initWorkZNode();
-			// handle dead server
-			handleDeadServer(workerZNode, Constants.WORKER_PREFIX, Constants.DELETE_ZK_OP);
 		} catch (Exception e) {
 			logger.error("register worker failure : "  + e.getMessage(),e);
+			System.exit(-1);
 		}
 	}
 	
@@ -167,16 +159,11 @@ public class ZKWorkerClient extends AbstractZKClient {
 							break;
 						case CHILD_REMOVED:
                             String path = event.getData().getPath();
-							// handle dead server, add to zk dead server path
-							handleDeadServer(path, Constants.WORKER_PREFIX, Constants.ADD_ZK_OP);
-
 							//find myself dead
-                            if(workerZNode.equals(path)){
+							String serverHost = getHostByEventDataPath(path);
-
+							if(checkServerSelfDead(serverHost, ZKNodeType.WORKER)){
-                                logger.warn(" worker server({}) of myself dead , stopping...", path);
+								return;
-                                stoppable.stop(String.format("worker server(%s) of myself dead , stopping",path));
+							}
-                            }
-							logger.info("node deleted : {}", event.getData().getPath());
 							break;
 						case CHILD_UPDATED:
 							break;