Apache 使用 http/1.0 响应，即使请求是 http/1.1

Question

我将 Apache Http 服务器 2.4 版配置为后端服务器(实际上是 Glassfish App Server)的代理。 MPM 是 worker。

配置大部分是默认的。代理配置

ProxyPass /context/ http://backend.com:8080/context/ keepalive=On ttl=25 timeout=300 max=50
ProxyPassReverse /context/ http://backend.com:8080/context/

我在浏览器中打开页面，它向 Apache 发送 GET http://example.com/context HTTP/1.1。 Apache 返回带有 Connection: close header 的响应 HTTP/1.0 200 OK。但实际后端服务器响应包含 HTTP/1.1 200 OK。

为什么 Apache 将代理响应从 1.1 降级到 1.0？

Answer 1

force-no-vary 是原因。文档说:

force-no-vary This causes any Vary fields to be removed from the response header before it is sent back to the client. Some clients don't interpret this field correctly; setting this variable can work around this problem. Setting this variable also implies force-response-1.0.

force-response-1.0 This forces an HTTP/1.0 response to clients making an HTTP/1.0 request. It was originally implemented as a result of a problem with AOL's proxies. Some HTTP/1.0 clients may not behave correctly when given an HTTP/1.1 response, and this can be used to interoperate with them.