// method of AbstractService
 @Override
 public synchronized void stop() {
   LOG.info("stop of UdaShuffleHandler");
   rdmaChannel.close();
   super.stop();
   LOG.info("stop of UdaShuffleHandler is done");
 }
 // method of AbstractService
 @Override
 public synchronized void start() {
   LOG.info("start of UdaShuffleHandler");
   rdmaChannel = new UdaPluginSH(config);
   super.start();
   LOG.info("start of UdaShuffleHandler is done");
 }
 // method of AbstractService
 @Override
 public synchronized void init(Configuration conf) {
   LOG.info("init of UdaShuffleHandler");
   this.config = conf;
   super.init(new Configuration(conf));
 }