Node.js v18.12.1 documentation

Cluster#

Source Code: lib/cluster.js

Clusters of Node.js processes can be used to run multiple instances of Node.js that can distribute workloads among their application threads. Node.js进程集群可用于运行Node.js的多个实例，这些实例可在其应用程序线程之间分配工作负载。When process isolation is not needed, use the worker_threads module instead, which allows running multiple application threads within a single Node.js instance.当不需要进程隔离时，请改用worker_threads模块，它允许在单个Node.js实例中运行多个应用程序线程。

The cluster module allows easy creation of child processes that all share server ports.集群模块允许轻松创建所有共享服务器端口的子进程。

import cluster from 'node:cluster';
import http from 'node:http';
import { cpus } from 'node:os';
import process from 'node:process';

const numCPUs = cpus().length;

if (cluster.isPrimary) {
  console.log(`Primary ${process.pid} is running`);

  // Fork workers.
  for (let i = 0; i < numCPUs; i++) {fork();
  }

  cluster.on('exit', (worker, code, signal) => {
    console.log(`worker ${worker.process.pid} died`);
  });
} 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(8000);

  console.log(`Worker ${process.pid} started`);
}const cluster = require('node:cluster');
const http = require('node:http');
const numCPUs = require('node:os').cpus().length;
const process = require('node:process');

if (cluster.isPrimary) {
  console.log(`Primary ${process.pid} is running`);

  // Fork workers.
  for (let i = 0; i < numCPUs; i++) {fork();
  }

  cluster.on('exit', (worker, code, signal) => {
    console.log(`worker ${worker.process.pid} died`);
  });
} 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(8000);

  console.log(`Worker ${process.pid} started`);
}

Running Node.js will now share port 8000 between the workers:运行Node.js将在worker之间共享端口8000：

$ node server.js
Primary 3596 is running
Worker 4324 started
Worker 4520 started
Worker 6056 started
Worker 5644 started

On Windows, it is not yet possible to set up a named pipe server in a worker.在Windows上，尚无法在worker中设置命名管道服务器。