Metatalk doesn't want me to be me!!!

July 18, 2007 3:57 PM

I'm logged into Metafilter as myself (Ramix) however when I click on the metatalk/askme links from Metfilter, it shows me logged in as user oxfcaf. Strangely though it shows me logged in as ramix as i am posting this thread. However when i navigate to askme from this posting page (metatalk) it shows me logged in as oxfcaf! What's going on?
posted by ramix to Bugs at 3:57 PM (18 comments total)

This has come up before. Something to do with multiple users on the same institutional IP, or something? I forget.
posted by dersins at 4:02 PM on July 18, 2007

Oh, here.
And possibly a few other places.
posted by dersins at 4:04 PM on July 18, 2007

Same proxy cache, I think. If you work for the same company, for example, or are otherwise both being served webpage by the same cache server, it may display a version of the page that was stored when the other person looked at the page you're now loading.

I'm pretty sure it's harmless—actual requests will not provide you with 0xFCAF's details or account priveleges or anything like that.
posted by cortex (staff) at 4:05 PM on July 18, 2007

And what he said.
posted by cortex (staff) at 4:06 PM on July 18, 2007

And why didn't you come down to the Portland meetup? People were asking about you.
posted by matildaben at 4:07 PM on July 18, 2007 [1 favorite]

Now 0xFCAF knows where you work.
posted by vacapinta at 4:13 PM on July 18, 2007

We should add this to the FAQ. You're behind a proxy with another mefi member, and you're seeing the home page loaded by them. When you comment though, it will go off your own cookie details, not anything cached on a server, so you'll be fine.
posted by mathowie (staff) at 4:39 PM on July 18, 2007

I am totally stalking you now
posted by 0xFCAF at 4:52 PM on July 18, 2007 [1 favorite]

It's in the FAQ. This is why we need those keywords hyperlinked.
posted by jessamyn (staff) at 4:55 PM on July 18, 2007

I am totally stalking you now

Boil his bunny! It's the only way to be sure.
posted by Mayor Curley at 4:58 PM on July 18, 2007

Boil his bunny!

Is that what the kids are calling it these days?
posted by dersins at 5:01 PM on July 18, 2007

Matt, do you serve pages with a "Vary: Cookie" header? It exists for this very purpose.
posted by cillit bang at 5:20 PM on July 18, 2007

I'd just like to take a moment to say that ramix kicks my ass at Scrabble. That is all.
posted by blueberry at 8:56 PM on July 18, 2007

This is why you should bitchslap anyone who advocates IP banning as an admin technique.
posted by Mitheral at 9:37 PM on July 18, 2007

There is wisdom to what cillit bang sez.
posted by davejay at 9:54 PM on July 18, 2007

Is that what the kids are calling it these days?

Yeah. That and "nuking from orbit."
posted by brundlefly at 10:02 PM on July 18, 2007

To expand, some caches need to be told that MeFi sends different content depending on the user's cookies. The "Vary" header allows you to do that. You send it out with a page to tell caches which HTTP request headers the content of the page is dependent on, so that they can cache things correctly.

Since cookies are sent in a request header named Cookie, you simply need to send a "Vary: Cookie" header out with every page that varies by cookies.
posted by cillit bang at 5:07 AM on July 19, 2007

Sorry to add to this rather later than the rest, but chucking it in the FAQ kinda sucks.

It's a bug. Mostly you see it when someone uses 'Expires:' or 'no-cache' without realising that none of the major caching proxies pay any attention to it (because they both became worthless about ten years ago when every numbnut chasing page impressions switched it on).

"Vary:" is the answer. Ironically, by removing the need for lots of client-side force-reloads, it also reduces stress on Mefi's own database by not needlessly generating expensive pages twice as often as they should be.
posted by genghis at 10:50 PM on July 21, 2007