diff --git a/backend/services/node.go b/backend/services/node.go
index d3409ed2..8b1f998a 100644
--- a/backend/services/node.go
+++ b/backend/services/node.go
@@ -100,13 +100,13 @@ func handleNodeInfo(key string, data Data) {
 	defer s.Close()
 
 	// 同个key可能因为并发，被注册多次
-	//var nodes []model.Node
-	//_ = c.Find(bson.M{"key": key}).All(&nodes)
-	//if nodes != nil && len(nodes) > 1 {
-	//	for _, node := range nodes {
-	//		_ = c.RemoveId(node.Id)
-	//	}
-	//}
+	var nodes []model.Node
+	_ = c.Find(bson.M{"key": key}).All(&nodes)
+	if nodes != nil && len(nodes) > 1 {
+		for _, node := range nodes {
+			_ = c.RemoveId(node.Id)
+		}
+	}
 
 	var node model.Node
 	if err := c.Find(bson.M{"key": key}).One(&node); err != nil {
diff --git a/backend/services/task.go b/backend/services/task.go
index 12f0330e..b79dbe7a 100644
--- a/backend/services/task.go
+++ b/backend/services/task.go
@@ -100,10 +100,104 @@ func AssignTask(task model.Task) error {
 	return nil
 }
 
+// 设置环境变量
+func SetEnv(cmd *exec.Cmd, envs []model.Env, taskId string, dataCol string) *exec.Cmd {
+	// 默认环境变量
+	cmd.Env = append(cmd.Env, "CRAWLAB_TASK_ID="+taskId)
+	cmd.Env = append(cmd.Env, "CRAWLAB_COLLECTION="+dataCol)
+	cmd.Env = append(cmd.Env, "PYTHONUNBUFFERED=0")
+	cmd.Env = append(cmd.Env, "PYTHONIOENCODING=utf-8")
+
+	//任务环境变量
+	for _, env := range envs {
+		cmd.Env = append(cmd.Env, env.Name+"="+env.Value)
+	}
+
+	// TODO 全局环境变量
+	return cmd
+}
+
+func SetLogConfig(cmd *exec.Cmd, path string) error {
+	fLog, err := os.Create(path)
+	if err != nil {
+		log.Errorf("create task log file error: %s", path)
+		debug.PrintStack()
+		return err
+	}
+	defer fLog.Close()
+	cmd.Stdout = fLog
+	cmd.Stderr = fLog
+	return nil
+}
+
+func FinishOrCancelTask(ch chan string, cmd *exec.Cmd, t model.Task) {
+	// 传入信号，此处阻塞
+	signal := <-ch
+	log.Infof("process received signal: %s", signal)
+
+	if signal == constants.TaskCancel && cmd.Process != nil {
+		// 取消进程
+		if err := syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL); err != nil {
+			log.Errorf("process kill error: %s", err.Error())
+			debug.PrintStack()
+
+			t.Error = "kill process error: " + err.Error()
+			t.Status = constants.StatusError
+		} else {
+			t.Error = "user kill the process ..."
+			t.Status = constants.StatusCancelled
+		}
+	} else {
+		// 保存任务
+		t.Status = constants.StatusFinished
+	}
+
+	t.FinishTs = time.Now()
+	_ = t.Save()
+}
+
+func StartTaskProcess(cmd *exec.Cmd, t model.Task) error {
+	if err := cmd.Start(); err != nil {
+		log.Errorf("start spider error:{}", err.Error())
+		debug.PrintStack()
+
+		t.Error = "start task error: " + err.Error()
+		t.Status = constants.StatusError
+		t.FinishTs = time.Now()
+		_ = t.Save()
+		return err
+	}
+	return nil
+}
+
+func WaitTaskProcess(cmd *exec.Cmd, t model.Task) error {
+	if err := cmd.Wait(); err != nil {
+		log.Errorf("wait process finish error: %s", err.Error())
+		debug.PrintStack()
+
+		if exitError, ok := err.(*exec.ExitError); ok {
+			exitCode := exitError.ExitCode()
+			log.Errorf("exit error, exit code: %d", exitCode)
+
+			// 非kill 的错误类型
+			if exitCode != -1 {
+				// 非手动kill保存为错误状态
+				t.Error = err.Error()
+				t.FinishTs = time.Now()
+				t.Status = constants.StatusError
+				_ = t.Save()
+			}
+		}
+
+		return err
+	}
+	return nil
+}
+
 // 执行shell命令
 func ExecuteShellCmd(cmdStr string, cwd string, t model.Task, s model.Spider) (err error) {
-	log.Infof("cwd: " + cwd)
-	log.Infof("cmd: " + cmdStr)
+	log.Infof("cwd: %s", cwd)
+	log.Infof("cmd: %s", cmdStr)
 
 	// 生成执行命令
 	var cmd *exec.Cmd
@@ -116,84 +210,29 @@ func ExecuteShellCmd(cmdStr string, cwd string, t model.Task, s model.Spider) (e
 	// 工作目录
 	cmd.Dir = cwd
 
-	// 指定stdout, stderr日志位置
-	fLog, err := os.Create(t.LogPath)
-	if err != nil {
-		HandleTaskError(t, err)
+	// 日志配置
+	if err := SetLogConfig(cmd, t.LogPath); err != nil {
 		return err
 	}
-	defer fLog.Close()
-	cmd.Stdout = fLog
-	cmd.Stderr = fLog
 
-	// 添加默认环境变量
-	cmd.Env = append(cmd.Env, "CRAWLAB_TASK_ID="+t.Id)
-	cmd.Env = append(cmd.Env, "CRAWLAB_COLLECTION="+s.Col)
-
-	// 添加任务环境变量
-	for _, env := range s.Envs {
-		cmd.Env = append(cmd.Env, env.Name+"="+env.Value)
-	}
+	// 环境变量配置
+	cmd = SetEnv(cmd, s.Envs, t.Id, s.Col)
 
 	// 起一个goroutine来监控进程
 	ch := utils.TaskExecChanMap.ChanBlocked(t.Id)
-	go func() {
-		// 传入信号，此处阻塞
-		signal := <-ch
-		log.Infof("cancel process signal: %s", signal)
-		if signal == constants.TaskCancel && cmd.Process != nil {
-			// 取消进程
-			if err := syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL); err != nil {
-				log.Errorf("process kill error: %s", err.Error())
-				debug.PrintStack()
-			}
-			t.Status = constants.StatusCancelled
-			t.Error = "user kill the process ..."
-		} else {
-			// 保存任务
-			t.Status = constants.StatusFinished
-		}
-		t.FinishTs = time.Now()
-		if err := t.Save(); err != nil {
-			log.Infof("save task error: %s", err.Error())
-			debug.PrintStack()
-			return
-		}
-	}()
 
-	// 在选择所有节点执行的时候，实际就是随机一个节点执行的，
+	go FinishOrCancelTask(ch, cmd, t)
+
+	// kill的时候，可以kill所有的子进程
 	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
 
-	// 异步启动进程
-	if err := cmd.Start(); err != nil {
-		log.Errorf("start spider error:{}", err.Error())
-		debug.PrintStack()
+	// 启动进程
+	if err := StartTaskProcess(cmd, t); err != nil {
 		return err
 	}
 
-	// 保存pid到task
-	t.Pid = cmd.Process.Pid
-	if err := t.Save(); err != nil {
-		log.Errorf("save task pid error: %s", err.Error())
-		debug.PrintStack()
-		return err
-	}
 	// 同步等待进程完成
-	if err := cmd.Wait(); err != nil {
-		log.Errorf("wait process finish error: %s", err.Error())
-		debug.PrintStack()
-		if exitError, ok := err.(*exec.ExitError); ok {
-			exitCode := exitError.ExitCode()
-			log.Errorf("exit error, exit code: %d", exitCode)
-			// 非kill 的错误类型
-			if exitCode != -1 {
-				// 非手动kill保存为错误状态
-				t.Error = err.Error()
-				t.FinishTs = time.Now()
-				t.Status = constants.StatusError
-				_ = t.Save()
-			}
-		}
+	if err := WaitTaskProcess(cmd, t); err != nil {
 		return err
 	}
 	ch <- constants.TaskFinish