为什么不遵守 gzip 最小长度指令？

Question

如果我理解正确，最好不要 gzip 小资源，因为它们实际上可能会变大，同时仍然对 CPU 造成性能影响。所以使用 gzip_min_length 指令是一个明显的解决方案。但是，在运行 REST API 的服务器上尝试此操作时，我正在处理这似乎不起作用。当我收到一个空的 json 响应，或者一个非常小的响应时，Content-Encoding header 仍然存在并且读取 "gzip".

HTTP Response headers

我的问题是为什么 NginX 不遵守此设置，我该如何解决它？

API 建立在 Lumen 微框架之上。

我已附上我在 nginx.conf:

中使用的 Gzip 设置

  # Compression

  # Enable Gzip compressed.
  gzip on;

  # Enable compression both for HTTP/1.0 and HTTP/1.1.
  gzip_http_version  1.1;

  # Compression level (1-9).
  # 5 is a perfect compromise between size and cpu usage, offering about
  # 75% reduction for most ascii files (almost identical to level 9).
  gzip_comp_level    5;

  # Don't compress anything that's already small and unlikely to shrink much
  # if at all (the default is 20 bytes, which is bad as that usually leads to
  # larger files after gzipping).
  gzip_min_length    1000;

  # Compress data even for clients that are connecting to us via proxies,
  # identified by the "Via" header (required for CloudFront).
  gzip_proxied       any;

  # Tell proxies to cache both the gzipped and regular version of a resource
  # whenever the client's Accept-Encoding capabilities header varies;
  # Avoids the issue where a non-gzip capable client (which is extremely rare
  # today) would display gibberish if their proxy gave them the gzipped version.
  gzip_vary          on;

  # Compress all output labeled with one of the following MIME-types.
  gzip_types
    application/atom+xml
    application/javascript
    application/json
    application/rss+xml
    application/vnd.ms-fontobject
    application/x-font-ttf
    application/x-web-app-manifest+json
    application/xhtml+xml
    application/xml
    font/opentype
    image/svg+xml
    image/x-icon
    text/css
    text/plain
    text/x-component;
  # text/html is always compressed by HttpGzipModule

Answer 1

确认我上面的注释，这似乎与 NGINX gzip module documentation 中的注释相对应 "The length is determined only from the “Content-Length” response header field."

使用 gzip_min_length 1000;，我的 JSON 响应被压缩，即使它们只有 100 个字节。

我更改了我的应用程序以添加 Content-Length: 100 header 并且 NGINX 发送 JSON 响应而不使用 gzip 编码。

如果我将配置更改为具有相同 100 字节 Content-Length 的 gzip_min_length 80;，则 NGINX 会按预期应用 gzip 编码。

简而言之：您需要为 NGINX 应用 Content-Length header 才能正确处理 gzip_min_length 检查。

为什么不遵守 gzip 最小长度指令？

Why is the gzip minimum length directive not being respected?

gzip

nginx

httpresponse

server

lumen