/** This method adds the {@link #JOBKEY_DATABASE_UPDATE_INSTANT} job to the scheduler. */
 public void startInstantDatabaseUpdate() {
   try {
     if (!sched.checkExists(JOBKEY_DATABASE_UPDATE_INSTANT)) {
       sched.addJob(instantDatabaseUpdateJob, true);
     }
     if (!QuartzUpdateDatabaseJob.IS_RUNNING) {
       sched.triggerJob(JOBKEY_DATABASE_UPDATE_INSTANT);
     }
   } catch (SchedulerException ex) {
     Logger.getLogger(QuartzSchedulerController.class.getName()).log(Level.SEVERE, null, ex);
     throw new WebApplicationException(PreparedServerResponses.ERROR_SCHEDULER);
   }
 }