On Fri, May 17, 2013 at 8:13 AM, Ben Niven-Jenkins
<[email protected]>wrote:
>
> On 17 May 2013, at 14:49, Wendy Roome wrote:
>
> > I assume you're referring to {13.2} of RFC 2616. That section strikes me
> as "a royal kludge." (Privately I'd apply a much stronger adjective, but
> I'm too much of a lady to use such language in public.)
> >
> > The problem is that HTTP defines multiple ways to declare expiration
> times -- Expires header, cache directives, etc. Those mechanisms have
> evolved over time, and not all servers use them consistently. So I think
> {13.2} is mostly about how to cope with legacy HTTP servers and missing or
> inconsistent information.
> >
> > Since we're starting fresh, why not just say that if an ALTO server
> wants to indicate a polling interval, it SHOULD set the Expires and the
> Date headers, and the client SHOULD use the difference as the approximate
> polling interval?
>
> That's basically what I was suggesting except rather than being specific
> about what the server must use, leave it to the client to determine based
> on how the client calculates freshness (as the client is likely in the best
> position to know what rate it might want to poll at as it know how
> up-to-date with any changes it might want to be).
>
I'm fine with adding a statement such as the following:
An ALTO Client determines the frequency at which ALTO information is
refreshed, and MAY be determined based on freshness information made
available via HTTP.
How does that sound?
>
> If we're going to pick one mechnaism I;d prefer we pick Cache-Control:
> max-age myself rather than Date/Expires (as max-age takes priority over
> Expires according to RFC2616).
>
I don't think that ALTO is the place to recommend one or the other. If this
is desired, it seems like this should be something in httpbis (if it isn't
already), or a different draft independent of ALTO.
Rich
> Ben
>
> >
> > - Wendy Roome
> >
> > From: Ben Niven-Jenkins <[email protected]>
> > Date: Thu, May 16, 2013 17:27
> > Subject: Re: [alto] Should server use "Expires" HTTP header
> >
> > Best current practice is to only to poll as often as you would
> revalidate the content (i.e. no more frequently than the instant the
> content becomes stale according to RFC2616).
>
>
_______________________________________________
alto mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/alto
