var cluster = require('cluster'); 
var data = 0;//这里定义数据不会被所有进程共享，各个进程有各自的内存区域 
if (cluster.isMaster) { //主进程 
        var numCPUs = require('os').cpus().length; 
            for (var i = 0; i < numCPUs; i++) { 
                        var worker = cluster.fork(); 
                            }    
                data++; 
                    console.log('DATA VALUE in MainProcess: %d ' , data);
} else { //子进程,会被调用numCPUs次 
        data++; 
            console.log('DATA VALUE in ChildProcess %d: %d ' ,cluster.worker.id, data);
}