On Sun, Jun 26, 2011 at 01:52:36PM +0200, Martin Pelikan wrote: > On Sat, Jun 25, 2011 at 11:58:25PM +0200, Claudio Jeker wrote: > > The problem with slow loading pages is more because of all the crap they > > load. Like the facebook and twitter iframes that take ages to load. And > > prefecthing will make it worse because the servers will all be busy > > serving prefetching clients of other users that will most probably never > > visit the site. > > I haven't really hacked on web servers much (only checked nginx for > some other stuff), but I always thought it worked like this: > > - browsers have priority queues for things they are downloading, and as > they see <link> prefetches or the apropriate HTTP headers, they act > accordingly (meaning "low prio"); the moment the user wants something, > they stop/stall prefetching and go doing useful stuff > - servers/balancers have priority queues for new requests vs long active > streams for example, and reqs with "X-moz: prefetch" go to the lowest > priority; they may return some temporary error if they're too busy > - browsers accept that > - servers send errors to prefetch requests that would be uncacheable > > - there's a paper from Mozilla stating they keep two open connections > to each site in case one of them dies (maybe because of an aborted > prefetch)) which after marco's observations seems not true for webkit. > > If it's done other way, please tell me, so I'll stop spreading lies. > > Of course, as we both wrote, the problem starts when a site loads from > 10 different domains and browser with white screen waits for > "ads.adclickmanager.com". This is what I thought prefetching would solve > -> your browser would load all this slow shit and next click would be at > some reasonable speed. I don't know what facebook's or twitter's > iframes load and, more importantly, where from. > Sure, servers _can_ be busy. But browsers have time until the user > finishes reading. At both this sides stuff can time out after, say, > five seconds for these. In the worst case, who cares?
I do. For many reasons but lets only mention the most obvious one. My web browser is not the only app that uses bandwidth. And when I am not touching it it better fucking not waste my limited bandwidth. Ever. I share my bandwidth with multiple people in my household. There is no bandwidth margin for sellmeadultdiapers.com and letmetrackyourshit.gov. Web browsers are not valid OS'. They are meant for news, geeky interests and naked ladies. Alright, one more. What about the authorata coming knocking down your door because you downloaded some illegal garbage and now you have to prove it wasn't you but your browser instead? Or a legit site that got compromised and got a link embedded in the HTML unbeknownst to the site operator? etc etc. Prefetching just about anything is a dangerous and stupid idea that can have real world ramifications. The "benefits" are made up by people with misguided interest or malicious intent for these types of technologies.
