code: public void start() throws IOException, ConnectionFailedException {
      LOG.info("Start Alluxio job service");
      setupTest();
      updateTestConf();
      startMaster();
      TestUtils.waitForReady(mMaster);
      startWorker();
      TestUtils.waitForReady(mWorker);
    }
docs: Starts both master and a worker using the configurations in test conf respectively.
  
  @throws IOException if an I/O error occurs
  @throws ConnectionFailedException if network connection failed