https://www.bufio.cn/tags/https/Recent content in HTTPS on 随手记Hugozh-cn© 2026 <a href="https://beian.miit.gov.cn/" target="_blank" rel="noopener">苏ICP备2023022553号-1</a>Wed, 29 Apr 2026 15:05:00 +0800https://www.bufio.cn/posts/http-request-flow-browser-nginx-backend/Wed, 29 Apr 2026 15:05:00 +0800https://www.bufio.cn/posts/http-request-flow-browser-nginx-backend/<p>我们在浏览器里输入一个网址，比如：</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-text" data-lang="text"><span class="line"><span class="cl">https://www.example.com/api/users </span></span></code></pre></div><p>看起来只是按下回车，页面就返回了。但在这几百毫秒甚至几十毫秒里，浏览器、操作系统、DNS、TCP、TLS、Nginx、后端应用、数据库和缓存可能都参与了一次协作。</p> <p>这篇文章按时间顺序，把一次典型的 HTTPS 请求完整拆开：从浏览器发起请求，到 TCP 三次握手、TLS 密钥协商，再到 Nginx 接收连接、反向代理给后端服务，最后响应返回浏览器。</p> <h2 id="总览请求链路长什么样">总览：请求链路长什么样</h2> <p>可以先看一个简化版流程图：</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-text" data-lang="text"><span class="line"><span class="cl">用户输入 URL </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ▼ </span></span><span class="line"><span class="cl">浏览器解析 URL </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ▼ </span></span><span class="line"><span class="cl">DNS 解析域名 -&gt; 得到服务器 IP </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ▼ </span></span><span class="line"><span class="cl">TCP 三次握手 -&gt; 建立可靠连接 </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ▼ </span></span><span class="line"><span class="cl">TLS 握手/密钥协商 -&gt; 建立加密通道 </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ▼ </span></span><span class="line"><span class="cl">浏览器发送 HTTP 请求 </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ▼ </span></span><span class="line"><span class="cl">Nginx 接收请求 </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ├─ 匹配 server_name </span></span><span class="line"><span class="cl"> ├─ 匹配 location </span></span><span class="line"><span class="cl"> ├─ 处理静态资源 / gzip / header / 日志 </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ▼ </span></span><span class="line"><span class="cl">proxy_pass 反向代理到后端应用 </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ▼ </span></span><span class="line"><span class="cl">后端应用处理业务逻辑 </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ▼ </span></span><span class="line"><span class="cl">后端返回 HTTP 响应 </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ▼ </span></span><span class="line"><span class="cl">Nginx 返回响应给浏览器 </span></span><span class="line"><span class="cl"> │ </span></span><span class="line"><span class="cl"> ▼ </span></span><span class="line"><span class="cl">浏览器解析 HTML/CSS/JS 并渲染页面 </span></span></code></pre></div><p>实际生产环境里，中间还可能有 CDN、负载均衡、WAF、Service Mesh、网关、缓存、队列、数据库等组件。但核心路径大体就是上面这些层次。</p>