This is an inner class created in response to ScheduledExecutorService silently stopping when a task throws an Exception. See http://stackoverflow.com/questions/6894595/scheduledexecutorservice-exception-handling

ExecutorMonitor.java

  private class ExecutorMonitor extends Thread {

    public ExecutorMonitor() {
      super("ExecutorMonitor");
    }

    @Override
    public void run() {
      while (enableAll || enabled) {
        LOG.info("Starting scheduler for task '{}'", task.getName());
        ScheduledFuture<?> scheduledTask = scheduledExecutorService.scheduleAtFixedRate(task, initialDelay, period,
            timeUnit);
        try {
          scheduledTask.get();
        } catch (ExecutionException e) {
          // The task threw an exception
          LOG.error(task.getName() + " failed", e.getCause());
          if (stopOnError) {
            LOG.warn("Scheduler for task '{}' stopping, must be restarted manually", task.getName());
            return;
          }
        } catch (InterruptedException e) {
          // Scheduler has been directed to stop via UI or JMX, or because of a system shutdown
          scheduledTask.cancel(false);
          LOG.info("Scheduler for task '{}' stopped", task.getName());
          return;
        }
      }
      LOG.info("NOT starting scheduler for task '{}', because it is disabled.", task.getName());
    }

  }