@abellsmythe/request-time 中文文档教程

Question

request-time

HTTP 请求的计时

了解和测量 HTTP 计时有助于我们发现性能。 客户端到服务器或服务器到服务器通信的瓶颈。

Timings explained

• DNS Lookup：执行 DNS 查找所花费的时间。 DNS 查找将域名解析为 IP 地址。 每个新域都需要一个完整的往返行程来进行 DNS 查找。

  • > There is no DNS lookup when the destination is already an IP address.

• TCP 连接：在源主机和目标主机之间建立 TCP 连接所花费的时间。 必须在多步握手过程中正确建立连接。 TCP 连接由操作系统管理，如果无法建立底层 TCP 连接，操作系统范围的 TCP 连接超时将否决我们应用程序的超时配置。

• TLS 握手：完成一次 TLS 握手所花费的时间。 在握手过程中，端点交换身​​份验证和密钥以建立或恢复安全会话。

  • > There is no TLS handshake with a not HTTPS request.

• Time to First Byte (TTFB)：等待初始响应所花费的时间。 除了等待服务器处理请求和传递响应所花费的时间之外，此时间还捕获到服务器的往返延迟。

• Content Transfer：接收响应数据所花费的时间。 响应数据的大小和可用的网络带宽决定了它的持续时间。

Installation

NPM：

npm install @abellsmythe/request-time

Usage

'use strict';

const https = require('https');
const timer = require('@abellsmythe/request-time').default;

const request = https.get('https://google.com');
const timings = timer(request);

request.on('response', response => {
    response.on('data', () => {
        // Do something
    });
    response.on('end', () => {
        console.log(timings);
    });
});

{
    start: 20019170.414002,
    socket: 20019171.943738,
    dnsLookup: 20019182.811348,
    connect: 20019194.637675,
    tlsHandshake: 20019245.32874,
    upload: 20019246.615841,
    response: 20019284.613933,
    end: 20019288.80115,
    error: undefined,
    phases:
    {
        wait: 1.5297359973192215,
        dns: 10.86761000007391,
        tcp: 11.826326999813318,
        request: 51.9781660027802,
        firstByte: 37.998091999441385,
        download: 4.187217000871897,
        total: 118.38714800029993
    }
}

API

timer(request)

返回：Object

• start - Time when the request started.
• socket - Time when a socket was assigned to the request.
• dnsLookup - Time when the DNS lookup finished.
• tlsHandshake - Time when the secure connection is done.
• connect - Time when the socket successfully connected.
• upload - Time when the request finished uploading.
• response - Time when the request fired the response event.
• end - Time when the response fired the end event.
• error - Time when the request fired the error event.
• phases
  • wait - timings.socket - timings.start
  • dns - timings.dnsLookup - timings.socket
  • tcp - timings.connect - timings.dnsLookup
  • request - timings.upload - timings.connect
  • firstByte - timings.response - timings.upload
  • download - timings.end - timings.response
  • total - timings.end - timings.start or timings.error - timings.start

如果尚未测量某些内容，它将是 undefined。

注意：时间是一个数字，表示自 UNIX 纪元以来未经过的毫秒数。

注意：request-time 使用来自节点的process.hrtime() 因为它不是时钟漂移的主题