public DFSClient() {
		jobToPartition = new ConcurrentHashMap<Integer, TreeMap<String, ArrayDeque<String>>>();
		try {
			this.folderPath = InetAddress.getLocalHost().getHostName() + "/";
			File folder = new File(folderPath);
			folder.mkdirs();
		} catch (UnknownHostException e) {
			e.printStackTrace();
		}
		// start the listener
		listener = new SlaveListener(this);
		Thread t = new Thread(listener);
		t.setDaemon(false);
		t.start();
	}