nginx protocol_error ai_generated true

上游发送了无效的状态行，从上游读取响应头时，客户端：10.0.0.1，服务器：example.com

upstream sent invalid status line while reading response header from upstream, client: 10.0.0.1, server: example.com

ID: nginx/upstream-sent-invalid-status-line-empty

其他格式: JSON · Markdown 中文 · English
76%修复率
84%置信度
1证据数
2023-11-12首次发现

版本兼容性

版本状态引入弃用备注
nginx 1.18.0 active — — —
nginx 1.20.1 active — — —
nginx 1.22.0 active — — —
nginx 1.24.0 active — — —

根因分析

上游服务器发送了格式错误的 HTTP 状态行（例如，空行或缺少 HTTP 版本），导致 nginx 无法解析响应。

English

Upstream server sends a malformed HTTP status line (e.g., empty or missing HTTP version), causing nginx to fail parsing the response.

generic

官方文档

https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_pass

解决方案

  1. Fix the upstream application to return a valid HTTP status line. For example, in a Python WSGI app, ensure the application returns a proper start line:
def application(environ, start_response):
    status = '200 OK'
    headers = [('Content-Type', 'text/plain')]
    start_response(status, headers)
    return [b'Hello World']
Check for missing or empty status strings in custom servers.
  2. Use nginx's proxy_pass with a rewrite to a different upstream that sanitizes responses, or place a reverse proxy like Varnish in front of the misbehaving upstream to normalize responses.

无效尝试

常见但无效的做法:

  1. Set proxy_http_version 1.1; 90% 失败

    The error is about a malformed status line, not the HTTP version. Changing proxy version does not fix upstream's invalid output.

  2. Increase proxy_read_timeout 95% 失败

    Timeout does not affect the format of the response; the upstream is responding, but with invalid data.

  3. Add proxy_buffering off; 92% 失败

    Buffering affects how nginx reads the response body, not the status line parsing in the header.