Re: dont-revalidate Cache-Control header

>
>
> > But again, why not just changing the page reload behavior by some
> directive
> > on the page reloaded, rather than changing the caching semantics of the
> > cached objects? Changing the caching semantics to make a url absolutely
> > permanent is dangerous as we discussed, you can freeze a page.
>
> Because a) this is about revalidation (Ctrl+r) rather than reloading
> (Ctrl+Shift+r) and b) revalidation also happens a lot from non-browser
> client and middleware. The latter is very unlikely to have even looked
> at the payload before trying its revalidation. If you put it in the
> payload it effectively becomes an end-to-end feature only of use to
> private caches (aka browser and closely related apps).
>
> >
> > My proposal to just specify the reload behavior for subresources
> (disabling
> > revalidation) on the page that causes the fetches looks a simple and less
> > dangerous. Just makes the reload button same as clicking on the url bar
> and
> > pressing enter again.
> >
>
> If this were a feature only of use to browsers. I would agree with you.
>
> But its also of potential use to shared/middleware caches for the same
> purpose of reducing revalidations. Which means header solutions are much
> preferrable over payload ones.
>
>
Yeah, I agree.

What I don't see is how to easily prevent the potential issues if a url
that is not versioned is marked as static by a hack/mistake. The
implications are really dangerous. The idea proposed of limiting to
sub-resources does not apply well for non-browsers and middleware. What
should be the behavior for non browsers in that case? How do you plan to
know in middleware/non-browser clients when things are / aren't
subresources?

If there is a non-browser client that is revalidating content, it's
probably because is configured to do so, it can be changed to not do so if
someone really wants that. There is a must-revalidate header that they
should be obeying, and in theory if its not set and ttl of cache not
expired, they should not be doing those revalidations.

That's why I think that the problem with revalidations mostly affects to
browsers, and why my proposal makes sense.

-- 
Guille -ℬḭṩḩø- <bishillo@gmail.com>
:wq

Received on Friday, 17 July 2015 23:11:07 UTC