Node.js http.request keepAlive

Question

我正在尝试使用http.Agent({ keepAlive: true})onhttp.request来保持连接打开以供将来的请求。

我创建了一个简单的服务器来记录每个新连接，但是当我运行request.js时，服务器会记录两个新连接。

如何将 HTTP keep-alive 与 Node.js 本机模块一起使用？

请求.js：

const http = require("http");

const agent = new http.Agent({
    keepAlive: true
});

var req1 = http.request({
    agent: agent,
    method: "GET",
    hostname: "localhost",
    port: 3000
}, function (res1) {
    console.log("REQUEST_1");

    var req2 = http.request({
        agent: agent,
        method: "GET",
        hostname: "localhost",
        port: 3000
    }, function (res2) {
        console.log("REQUEST_2");
    });

    req2.end();
});

req1.end();

服务器.js：

const http = require('http');

var server = http.createServer(function (req, res) {
    res.end('OK');
    console.log("REQUEST");
})

server.on('connection', function (socket) {
    console.log("NEW CONNECTION");
})

server.listen(3000);

输出：

NEW CONNECTION
REQUEST
NEW CONNECTION
REQUEST

Answer 1

设置maxSockets选项如下：

const agent = new http.Agent({
    keepAlive: true,
    maxSockets: 1
});

默认maxSockets设置为Infinity- https://nodejs.org/api/http.html#http_new_agent_options

节点 v10 上的完整示例

const http = require("http");

const agent = new http.Agent({
    keepAlive: true,
    maxSockets: 1
});

var req1 = http.request({
    agent: agent,
    method: "GET",
    hostname: "localhost",
    port: 3000
}, function (res1) {
    console.log("REQUEST_1");

    res1.on('data', function () {
        console.log("REQUEST_1 data");
    });

    res1.on('end', function () {
        console.log("REQUEST_1 end");
    });

    var req2 = http.request({
        agent: agent,
        method: "GET",
        hostname: "localhost",
        port: 3000
    }, function (res2) {
        console.log("REQUEST_2");

        res2.on('data', function () {
            console.log("REQUEST_2 data");
        });

        res2.on('end', function () {
            console.log("REQUEST_2 end");
        });
    });
    req2.end();
});
req1.end();