叢集示例

Node.js 的單個例項在單個執行緒中執行。為了利用多核系統,可以在 Node.js 程序叢集中啟動應用程式來處理負載。

cluster 模組允許你輕鬆建立所有共享伺服器埠的子程序。

下面的示例在主程序中建立 worker 子程序,以處理跨多個核的負載。

const cluster = require('cluster');
const http = require('http');
const numCPUs = require('os').cpus().length; //number of CPUS

if (cluster.isMaster) {
  // Fork workers.
  for (var i = 0; i < numCPUs; i++) {
    cluster.fork();    //creating child process
  }

  //on exit of cluster
  cluster.on('exit', (worker, code, signal) => {
      if (signal) {
        console.log(`worker was killed by signal: ${signal}`);
      } else if (code !== 0) {
        console.log(`worker exited with error code: ${code}`);
      } else {
        console.log('worker success!');
      }
  });
} else {
  // Workers can share any TCP connection
  // In this case it is an HTTP server
  http.createServer((req, res) => {
    res.writeHead(200);
    res.end('hello world\n');
  }).listen(3000);
}