protected synchronized void initializeScheduler() {
    StdSchedulerFactory sf = new StdSchedulerFactory();
    Properties properties = getQuartzSchedulerProperties();
    try {
      sf.initialize(properties);
    } catch (SchedulerException e) {
      LOG.warn("Failed to initialize Request Execution Scheduler properties !");
      LOG.debug("Scheduler properties: \n{}", properties);
      e.printStackTrace();
      return;
    }
    try {
      scheduler = sf.getScheduler();
      scheduler.setJobFactory(guiceJobFactory);
      isInitialized = true;
    } catch (SchedulerException e) {
      LOG.warn("Failed to create Request Execution scheduler !");
      e.printStackTrace();
    }
  }
Constructor used for unit testing
@param configuration
ambari-server/src/main/java/org/apache/ambari/server/scheduler/ExecutionSchedulerImpl.java