code: private static void addTriggers()
     {
        if (!PERSISTENCE_ENABLED)
        {
           return;
        }
        Runtime.getRuntime().addShutdownHook(new Thread("JCRStatisticsManager-Hook")
        {
           @Override
           public void run()
           {
              printData();
           }
        });
        Thread t = new Thread("JCRStatisticsManager-Writer")
        {
           @Override
           public void run()
           {
              while (true)
              {
                 try
                 {
                    sleep(PERSISTENCE_TIMEOUT);
                 }
                 catch (InterruptedException e)
                 {
                    LOG.debug("InterruptedException", e);
                 }
                 printData();
              }
           }
        };
        t.setDaemon(true);
        t.start();
     }
docs: Add all the triggers that will keep the file up to date only if the persistence
  is enabled.