// ����tuple���ͺ�������ϵͳstream����startup��Ϣ
List<Object> msg = new ArrayList<Object>();
msg.add("startup");
// ����task���ն���
TaskSendTargets sendTargets = makeSendTargets();
UnanchoredSend.send(topologyContext, sendTargets, workerTransfer,
Common.SYSTEM_STREAM_ID, msg);
// �����̣߳���zeroMq�ж�ȡtuple,����spout��bolt���д���Ȼ����worker
RunnableCallback componsementExecutor = mkExecutor(puller, sendTargets);