haproxy The Response line

1.3.1. The Response line
------------------------

Line 1 is the "response line". It is always composed of 3 fields :它总是由3个域组成

  - a version tag : HTTP/1.1   版本tag
  - a status code : 200        返回状态码
  - a reason      : OK

The status code is always 3-digit. The first digit indicates a general status :

状态代码总是三位数。第一位数字表示大致的状态


 - 1xx = informational message to be skipped (eg: 100, 101)
 - 2xx = OK, content is following   (eg: 200, 206)
 - 3xx = OK, no content following   (eg: 302, 304)
 - 4xx = error caused by the client (eg: 401, 403, 404)
 - 5xx = error caused by the server (eg: 500, 502, 503)

Please refer to RFC2616 for the detailed meaning of all such codes. The
"reason" field is just a hint, but is not parsed by clients. Anything can be
found there, but it's a common practice to respect the well-established
messages. It can be composed of one or multiple words, such as "OK", "Found",
or "Authentication Required".

请参见RFC2616的所有代码的具体含义 "reason" 域只是一个hint，但是不被客户端解析。

任何信息都能找到, 但他是一个普通的做法来遵守已经建立的消息。

Haproxy may emit the following status codes by itself :

HAPorxy 可以本身发出下面的代码

  Code  When / reason
   200  access to stats page, and when replying to monitoring requests
   301  when performing a redirection, depending on the configured code
   302  when performing a redirection, depending on the configured code
   303  when performing a redirection, depending on the configured code
   307  when performing a redirection, depending on the configured code
   308  when performing a redirection, depending on the configured code
   400  for an invalid or too large request
   401  when an authentication is required to perform the action (when
        accessing the stats page)
   403  when a request is forbidden by a "block" ACL or "reqdeny" filter
   408  when the request timeout strikes before the request is complete
   500  when haproxy encounters an unrecoverable internal error, such as a
        memory allocation failure, which should never happen
   502  when the server returns an empty, invalid or incomplete response, or
        when an "rspdeny" filter blocks the response.
   503  when no server was available to handle the request, or in response to
        monitoring requests which match the "monitor fail" condition
   504  when the response timeout strikes before the server responds

The error 4xx and 5xx codes above may be customized (see "errorloc" in section
4.2).