用NodeJS实现集群计算
Node的单个实例运行在单个的线程中，要充分利用多核系统，我们可以运行Node进程集群来处理负载。
也就是说，如果系统有8核，单个Node实例只能使用其中1核，可以利用cluster包的workers概念来充分利用所有的核。有趣的是，它们可以共享同一个端口。
该模块还处于实验阶段。
Number of request served = 0A worker with #2 is now connected to 0.0.0.0:8000A worker with #4 is now connected to 0.0.0.0:8000A worker with #1 is now connected to 0.0.0.0:8000A worker with #3 is now connected to 0.0.0.0:8000Number of request served = 0...Number of request served = 2..Number of request served = 4...Number of request served = 6
