node.js中cluster的使用教程

var cluster = require('cluster'); 
var http = require('http'); 
var numCPUs = require('os').cpus().length; 
if (cluster.isMaster) { 
// 创建工作进程 
for (var i = 0; i < numCPUs; i++) { 
cluster.fork(); 
} 
cluster.on('death', function(worker) { 
console.log('worker ' + worker.pid + ' died'); 
cluster.fork();//重启子进程 
}); 
} else { 
// 工作进程创建http 服务器 
http.Server(function(req, res) { 
res.writeHead(200); 
res.end("hello world\n"); 
}).listen(8000); 
} 

var cluster = require('cluster'); 
var http = require('http'); 
var numCPUs = require('os').cpus().length; 
var rssWarn = (12 * 1024 * 1024) 
  , heapWarn = (10 * 1024 * 1024) 
if(cluster.isMaster) { 
  for(var i=0; i<numCPUs; i++) { 
    var worker = cluster.fork(); 
    worker.on('message', function(m) { 
      if (m.memory) { 
        console.log(m.memory.rss,rssWarn) 
        if(m.memory.rss > rssWarn) { 
          console.log('Worker ' + m.process + ' using too much memory.') 
        } 
      } 
 
    }) 
  } 
} else { 
// 服务器 
  http.createServer(function(req,res) { 
    res.writeHead(200); 
    res.end('hello world\n') 
  }).listen(8000) 
// 每秒报告一次状态 
  setInterval(function report(){ 
    process.send({memory: process.memoryUsage(), process: process.pid}); 
  }, 1000) 
} 

var cluster = require('cluster'); 
var http = require('http'); 
var numCPUs = require('os').cpus().length; 
var rssWarn = (50 * 1024 * 1024) 
  , heapWarn = (50 * 1024 * 1024) 
var workers = {} 
if(cluster.isMaster) { 
  for(var i=0; i<numCPUs; i++) { 
    createWorker() 
  } 
  setInterval(function() { 
    var time = new Date().getTime() 
    for(pid in workers) { 
      if(workers.hasOwnProperty(pid) && 
        workers[pid].lastCb + 5000 < time) { 
        console.log('Long running worker ' + pid + ' killed') 
        workers[pid].worker.kill() 
        delete workers[pid] 
        createWorker() 
      } 
    } 
  }, 1000) 
} else { 
// 服务器 
  http.Server(function(req,res) { 
// 打乱200 个请求中的1 个 
    if (Math.floor(Math.random() * 200) === 4) { 
      console.log('Stopped ' + process.pid + ' from ever finishing') 
      while(true) { continue } 
    } 
    res.writeHead(200); 
    res.end('hello world from ' + process.pid + '\n') 
  }).listen(8000) 
// 每秒钟报告一次状态 
  setInterval(function report(){ 
    process.send({cmd: "reportMem", memory: process.memoryUsage(), 
      process: process.pid}) 
  }, 1000) 
} 
function createWorker() { 
  var worker = cluster.fork() 
  console.log('Created worker: ' + worker.pid) 
// 允许开机时间 
  workers[worker.pid] = {worker:worker, lastCb: new Date().getTime()-1000} 
  worker.on('message', function(m) { 
    if(m.cmd === "reportMem") { 
      workers[m.process].lastCb = new Date().getTime() 
      if(m.memory.rss > rssWarn) { 
        console.log('Worker ' + m.process + ' using too much memory.') 
      } 
    } 
  }) 
}