- From: Mark Nottingham <mnot@mnot.net>
- Date: Wed, 1 Jun 2011 14:47:45 +1000
- To: Brian Pane <brianp@brianp.net>
- Cc: Poul-Henning Kamp <phk@phk.freebsd.dk>, httpbis Group <ietf-http-wg@w3.org>, Balachander Krishnamurthy <bala@research.att.com>, cew@cs.wpi.edu
On 01/06/2011, at 2:46 PM, Brian Pane wrote: > On Tue, May 31, 2011 at 3:05 PM, Mark Nottingham <mnot@mnot.net> wrote: > [...] >> I keep the associations in memory (hashed in some cases to preserve space), and that seems to work well. > > Does that mean that your implementation, upon seeing a response for > resource A that contains a Link header that invalidates resource B, > will persistently retain the knowledge that changes to A should > invalidate B? Yes, until another response is received with differing information. > I'd been assuming that the invalidation of B would be a one-time > event: the receiving client or intermediary would invalidate B in its > cache and forget about the message thereafter. That's a scalable > model (in practice, implementations limit the max total header size > they'll allow per message, and that puts an upper bound on the number > of invalidations that a single response message can trigger). > Retaining the associations persistently is a much harder model to > scale. Remember that the association is bounded by the freshness lifetime of the response it was carried in; that keeps things reasonable. Cheers, -- Mark Nottingham http://www.mnot.net/
Received on Wednesday, 1 June 2011 04:48:13 UTC