Retry-After - [ HTTP 中文开发手册 ] - 在线原生手册

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文字

Retry-After响应的 HTTP 报头指示所述用户代理应该多长时间使一个后续请求之前等待。有两种主要的情况使用这个头文件：

When sent with a 503 (Service Unavailable) response, it indicates how long the service is expected to be unavailable.

当使用重定向响应（如301永久移动）发送时，它表示用户代理在发出重定向请求之前要求等待的最短时间。

Header type	Response header
Forbidden header name	no

句法

Retry-After: <http-date>Retry-After: <delay-seconds>

指令

<http-date> 之后重试的日期。有关DateHTTP 日期格式的更多详细信息，请参阅标头。<delay-seconds> 一个非负十进制整数，表示接收到响应后的延迟秒数。

例子

处理预定的停机时间

Retry-After对客户端和服务器上的标头的支持仍然不一致。但是，像 Googlebot 这样的一些抓取工具和抓取工具可以很好地尊重Retry-After标题。将它与503（服务不可用）响应一起发送是非常有用的，这样当停机时间结束时，搜索引擎将继续为您的站点编制索引。

Retry-After: Wed, 21 Oct 2015 07:28:00 GMT
Retry-After: 120

产品规格

Specification	Title
RFC 7231, section 7.1.3: Retry-After	Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content

浏览器兼容性

Feature	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic Support	?	(Yes)	No1	?	?	?

Feature	Android	Chrome for Android	Edge mobile	Firefox for Android	IE mobile	Opera Android	iOS Safari
Basic Support	?	?	(Yes)	?	?	?	?

见错误230260。参阅

Google 网站管理员博客：如何处理计划的网站停机时间

503 （暂停服务）

301 （永久移动）