Re: draft-asveren-dispatch-http-overload

On 2018-05-01 11:41, Asveren, Tolga wrote:
> I certainly will include these explanation, and more about a few other 
> issues, in the next version of the draft. My initial goal was to get 
> some initial idea/feedback from other folks.
> 
> Regarding interpretation of 503: I think it is quite clear, at least 
> IMHO, based on RFC2616 that it indicates the status of the server in 
> general not just for a single request:
> 
> *10.5.4 503 Service Unavailable*
> 
>     The server is currently unable to handle the request due to a
> 
>     temporary overloading or maintenance of the server. The implication
> 
>     is that this is a temporary condition which will be alleviated after
> 
>     some delay. If known, the length of the delay MAY be indicated in a
> 
>     Retry-After header. If no Retry-After is given, the client SHOULD
> 
>     handle the response as it would for a 500 response.
> 
> I also never saw it being interpreted/used on “per request” basis in 
> practice.
> ...

RFC 2616 is irrelevant. RFC 7231 says:

> The 503 (Service Unavailable) status code indicates that the server is currently unable to handle the request due to a temporary overload or scheduled maintenance, which will likely be alleviated after some delay. The server MAY send a Retry-After header field (Section 7.1.3) to suggest an appropriate amount of time for the client to wait before retrying the request.
> 
> Note: The existence of the 503 status code does not imply that a server has to use it when becoming overloaded. Some servers might simply refuse the connection.

That IMHO leaves the nature of the overload open; it could be the server 
itself, a specific service, or just one resource.

Best regards, Julian

Received on Tuesday, 1 May 2018 10:19:21 UTC