boolean enqueueSplitTask(String taskname, TaskBatch batch) {
    lastTaskCreateTime = EnvironmentEdgeManager.currentTime();
    String task = getSplitLogManagerCoordination().prepareTask(taskname);
    Task oldtask = createTaskIfAbsent(task, batch);
    if (oldtask == null) {
      // publish the task in the coordination engine
      getSplitLogManagerCoordination().submitTask(task);
      return true;
    }
    return false;
  }
Add a task entry to coordination if it is not already there.
@param taskname the path of the log to be split
@param batch    the batch this task belongs to
@return true if a new entry is created, false if it is already there.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/SplitLogManager.java