mnot’s blog

Great news, because its already supported in Squid, updating our current reverse proxies shall take a couple minutes.

From the first post, are there other similar situations where Yahoo found that similar extensions would leverage the caches role, but were left out?

Regards

Btw, the cache channel draft expired a while ago, and is so easy to implement on servers, besides it seems to add value for websites with hundreds of resources that change not so often. Any plans on its future?

There is no need for a stale-while-revalidate directive. Instead, they gray region in your diagram could just represent the last XX% of the resource's freshness window. If an incoming request is received during that tail part of the window, the cached response is returned (and is still fresh), with an asynchronous request still being used to expand the freshness window for future requests.

All you really need to know is when you asynchronously re-fetch the resource, its freshness will be a function of when you fetched it. Using the delta "max-age" directive (instead of "Expires") would seem to suggest this today.

Either way, if requests 2 and 3 are never received, 4 ends up blocking while the cache is refreshed.

Hi Mark, thanks for shepherding this through. Do you happen to have any notion of whether there is any interest and/or activity in adding support for these directives to modern browsers' caches? i.e. do you know of submitted feature requests open on Firefox, Opera, Chrome, Safari, IE, etc.

Randy -

That wouldn't work for cache hierarchies; when the child cache(s) pre-emptively request to refresh their cache, they'll get something with a very small freshness window, and they'll be forced to revalidate (and block the client).

Jon -

Not to my knowledge, although the pre- and post-check features in IE are functionally similar (but IMHO more confusing to use).

Cheers,