public void start() throws Exception {
		File base = new File("./data/cache/");
		for (int i = 0; i < THREADS_PER_REQUEST_TYPE; i++) {
			workers.add(new JagGrabRequestWorker(new IndexedFileSystem(base, true)));
			workers.add(new OnDemandRequestWorker(new IndexedFileSystem(base, true)));
		}
		
		for (RequestWorker<?, ?> worker : workers) {
			service.submit(worker);
		}
	}