Один из дополнительных кодов статуса HTTP (RFC6585)
Где можно найти примеры HTTP-заголовков HTTP-заголовков HTTP/REST, которые могут быть полезны с этим статусом ответа HTTP?
Примеры HTTP API Ограничение скорости HTTP-заголовков ответов
Ответ 1
Вот несколько примеров заголовков HTTP HTTP, ограничивающих HTTP-ответ. Взято из четырех общих API REST: Github, Vimeo, Twitter и Imgur:
Ограничение скорости Github http://developer.github.com/v3/#rate-limiting
#=============================#=============================================#
# HTTP Header # Description #
#=============================#=============================================#
| X-RateLimit-Limit | Request limit per hour |
+-----------------------------+---------------------------------------------+
| X-RateLimit-Remaining | The number of requests left for the time |
| | window |
+-----------------------------+---------------------------------------------+
Ограничение скорости Vimeo http://developer.vimeo.com/guidelines/rate-limiting
#=============================#=============================================#
# HTTP Header # Description #
#=============================#=============================================#
| X-RateLimit-Limit | Request limit per day / per 5 minutes |
+-----------------------------+---------------------------------------------+
| X-RateLimit-Remaining | The number of requests left for the time |
| | window |
+-----------------------------+---------------------------------------------+
| X-RateLimit-Reset | The remaining window before the rate limit |
| | resets in UTC epoch seconds |
+-----------------------------+---------------------------------------------+
Ограничение скорости передачи данных REST для Twitter https://dev.twitter.com/docs/rate-limiting/1.1
Примечание. Twitter использует заголовки с похожими именами, такими как Vimeo, но имеет другое тире в каждом имени.
#=============================#=============================================#
# HTTP Header # Description #
#=============================#=============================================#
| X-Rate-Limit-Limit | The rate limit ceiling for that given |
| | request |
+-----------------------------+---------------------------------------------+
| X-Rate-Limit-Remaining | The number of requests left for the |
| | 15 minute window |
+-----------------------------+---------------------------------------------+
| X-Rate-Limit-Reset | The remaining window before the rate limit |
| | resets in UTC epoch seconds |
+-----------------------------+---------------------------------------------+
Ограничения скорости API Imgur http://api.imgur.com/
#=============================#=============================================#
# HTTP Header # Description #
#=============================#=============================================#
| X-RateLimit-UserLimit | Total credits that can be allocated |
+-----------------------------+---------------------------------------------+
| X-RateLimit-UserRemaining | Total credits available |
+-----------------------------+---------------------------------------------+
| X-RateLimit-UserReset | Timestamp (unix epoch) for when the credits |
| | will be reset |
+-----------------------------+---------------------------------------------+
| X-RateLimit-ClientLimit | Total credits that can be allocated for the |
| | application in a day |
+-----------------------------+---------------------------------------------+
| X-RateLimit-ClientRemaining | Total credits remaining for the application |
| | in a day |
+-----------------------------+---------------------------------------------+
Ответ 2
В дополнение к конкретным API-заголовкам не забывайте о скромном стандартном заголовке Retry-After.