Node.js http.globalAgent 属性

http.globalAgent （在 v0.5.9 中添加）属性是“http”模块的内置属性，用作所有 HTTP 客户端请求的默认值。它是代理的全局实例。

代理维护给定主机和端口的待处理请求队列，为每个请求重用单个套接字连接，直到队列为空，此时套接字要么被销毁，要么被放入一个池中，以便再次使用请求相同的主机和端口。

为了得到响应和正确的结果，我们需要导入' http '模块。

进口：

const http = require('http');

句法：

http.globalAgent

参数：此属性不接受上述任何参数。

返回值< http.Agent > ：负责管理连接持久性和 HTTP 客户端的重用。

下面的示例说明了在 Node.js 中使用http.globalAgent属性。

示例 1：文件名：index.js

// Node.js program to demonstrate the 
// http.globalAgent Method
  
// Importing http module
var http = require('http');
const { globalAgent } = require('http');
  
const PORT = process.env.PORT || 3000;
  
console.log(globalAgent);
  
// Creating http Server
var httpServer = http.createServer(
      function(request, response) {
  
  console.log(globalAgent);
  
  var Output = "Hello Geeksforgeeks..., "
    + "Output of global agent is: " +
  JSON.stringify(globalAgent);
  
  // Prints Output on the browser in response
  response.write(Output);
  response.end('ok');
});
  
// Listening to http Server
httpServer.listen(PORT, ()=>{
   console.log("Server is running at port 3000...");
});

使用以下命令运行index.js文件：

node index.js

输出：

In Console

>> Server is running at port 3000…

Agent { _events: [Object: null prototype] {

   free: [Function (anonymous)],

   newListener: [Function: maybeEnableKeylog]}, _eventsCount: 2,

 _maxListeners: undefined, defaultPort: 80,

 protocol: ‘http:’, options: { path: null },

 requests: {}, sockets: {},

 freeSockets: {}, keepAliveMsecs: 1000,

 keepAlive: false, maxSockets: Infinity,

 maxFreeSockets: 256, scheduling: ‘fifo’,

 maxTotalSockets: Infinity, totalSocketCount: 0,

 [Symbol(kCapture)]: false}

现在在浏览器中运行http://localhost:3000/ 。

Output: In Browser

Hello Geeksforgeeks…, global agents are: {“_events”:{}, “_eventsCount”:2, “defaultPort”:80,

“protocol”:”http:”, “options”:{“path”:null}, “requests”:{}, “sockets”:{},

“freeSockets”:{}, “keepAliveMsecs”:1000, “keepAlive”:false, “maxSockets”:null, “maxFreeSockets”:256,

“scheduling”:”fifo”, “maxTotalSockets”:null, “totalSocketCount”:0}ok

参考： https://nodejs.org/api/http.html#http_http_globalagent