public void scheduleJob(Trigger trigger) {
    LOG.debug("Scheduling job: {}", trigger.getJobKey());
    if (isSchedulerAvailable()) {
      try {
        executionScheduler.scheduleJob(trigger);
      } catch (SchedulerException e) {
        LOG.error("Unable to add trigger for execution job: " + trigger
          .getJobKey(), e);
      }
    } else {
      LOG.error("Scheduler unavailable, cannot schedule jobs.");
    }
  }
Add trigger for a job to the scheduler
@param trigger
ambari-server/src/main/java/org/apache/ambari/server/scheduler/ExecutionScheduleManager.java