Node.js有效处理并发连接的过程

const http = require('http');

const server = http.createServer((req, res) => {
    // 一些异步操作，比如读取数据库
    setTimeout(() => {
        res.writeHead(200, {'Content-Type': 'text/plain'});
        res.end('Hello, World!');
    }, 2000); // 模拟延迟
});

// 服务器在指定端口上监听
server.listen(3000, () => {
    console.log('Server is running at http://localhost:3000/');
});

const fs = require('fs');

const server = http.createServer((req, res) => {
    fs.readFile('example.txt', 'utf8', (err, data) => {
        if (err) {
            res.writeHead(500);
            return res.end('Error loading file');
        }
        res.writeHead(200, {'Content-Type': 'text/plain'});
        res.end(data);
    });
});

server.listen(3000, () => {
    console.log('Server is running at http://localhost:3000/');
});

const cluster = require('cluster');
const http = require('http');
const numCPUs = require('os').cpus().length; // 获取 CPU 核心数

if (cluster.isMaster) {
    for (let i = 0; i < numCPUs; i++) {
        cluster.fork(); // 创建工作进程
    }
    
    cluster.on('exit', (worker, code, signal) => {
        console.log(`Worker ${worker.process.pid} died`);
    });
} else {
    http.createServer((req, res) => {
        res.writeHead(200);
        res.end('Hello from worker ' + process.pid);
    }).listen(3000);
}

// 避免
const result = fs.readFileSync('example.txt', 'utf8');

// 而是
fs.readFile('example.txt', 'utf8', (err, data) => {
    // 处理数据
});