code: public void start() throws Exception {
          started = true;
          setLogFileDir(logFileDir);
          LOGGER.debug("Initiating transaction manager recovery");
          recovered = new HashMap<>();
  
          logger.open(null);
  
          ReplayListener replayListener = new GeronimoReplayListener(xidFactory, recovered);
          logger.replayActiveTx(replayListener);
  
          LOGGER.debug("In doubt transactions recovered from log");
      }
docs: Starts the logger.
  @throws Exception cannot be started