浏览器限制同一个域名的并发请求数

在ajax中限制同是对同一个域名的并发请求限制

• Chrome 最大并发请求数目为 6，这个限制还有一个前提是针对同一域名的，超过这一限制的后续请求将会被阻塞。

chrome 源码写死的

// Default to allow up to 6 connections per host. Experiment and tuning may
// try other values (greater than 0).  Too large may cause many problems, such
// as home routers blocking the connections!?!?  See http://crbug.com/12066.
int g_max_sockets_per_group[] = {
  6,  // NORMAL_SOCKET_POOL
  255 // WEBSOCKET_SOCKET_POOL
};

实验验证 chrome Network 网络 3G

• svc node

// connection.js
const http = require('http');
const fs = require('fs');
const port = 3010;
http.createServer((request, response) => {
  console.log('request url: ', request.url);
  const html = fs.readFileSync('./connection.html', 'utf-8');
  const img = fs.readFileSync('./test_img.jpg');
  if (request.url === '/') {
    response.writeHead(200, { 'Content-Type': 'text/html' });
    response.end(html);
  } else {
    response.writeHead(200, { 'Content-Type': 'image/jpg' });
    response.end(img);
  }
}).listen(port);
console.log('server listening on port ', port);

限制请求