On Mon, Mar 7, 2011 at 4:23 PM, Thanos Diacakis <tha...@diacakis.com> wrote: > I have spent several hours researching this, and I'm stumped, so > perhaps I could tap into some collective wisdom: > > I have a website whose page template includes a "Sign-In or Register" > link at the top. This is shown on pretty much every page. If the > user is already signed in, this is replaced with "Hello _username_ | > My Account". This is done by passing request.user to the template and > checking is_authenticated(). > > The problem is, that as soon as I touch request.user, the Vary: Cookie > header is tagged on, and that destroys caching. Every anonymous user > gets their own version of the page cached, which is almost pointless. > > I'm trying to figure out a way that I can fully utilize the cache for > anonymous users (i.e. one instance of the rendered page in the cache) > and I'm OK for caching with Vary: Cookie for logged in users. > > So, is there a way to figure out if the user is logged in or not, > without tripping the Vary: Cookie header, or is there a better way of > doing this altogether? > > BTW, it seems that it is significantly faster (15x CPU time) to cache > a whole view, that to cache a fragment, so I'd like to avoid that if > possible. > > Thanks > > Thanos >
If it is the same URL being visited by the anonymous users and the authenticated users, then how is the upstream cache to determine which version to send? Or put it like this, you want to have anonymous users viewing the page to not generate a 'Vary: cookie' header. This leads to the following situation: Anonymous user visits /contact-us/ Django generates the anonymous version of the page and delivers it, with appropriate caching headers. Upstream cache stores anonymous version in cache Logged in user visits /contact-us/ Upstream cache intercepts the request, looks in its cache for an appropriate hit, and delivers the anonymous page. The basic thing here is that you cannot have your cake and eat it as well. Either the page contains dynamic, user-specific content, in which case vary on cookie, or it does not, in which case cache it. If you want to deliver truly cache-able anonymous content, deliver it on a different URL to your dynamic content. Cheers Tom -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
