Trackbacks

July 15, 2004 2:45 PM

How exactly does Trackback work? I posted something on this site that incorporates and links back to Emptyage's excellent post on Steve Jobs' attempt to tear down the house currently on his property in Woodside. I link back to the comments at Metafilter; is that all I have to do? The "trackback" section below the post in the Typepad backend is blank; shouldn't it list the Mefi post?

I just don't understand how Typepad knows there is a trackback- and do they go both directions or only one? I am easily confused. Does MT check every single link to see if its to a trackback-supporting weblog?

posted by luriete to computers & internet (5 comments total)

Trackback is goes from you (the linker) to the other site (the, uh, linkee). If they support trackback, they will then link back to you -- basically a (debatably) more precise method of publishing a referrer list.

Your trackback section will not list the mefi post: it shows trackbacks you receive from others, not the ones you send. Also, your trackback won't show up on the mefi page, because mefi currently has trackbacks disabled (they were being abused, and mathowie couldn't be bothered to remove the HTML from them).

MT does, indeed, check every link to see if it is a trackback-supporting weblog, which is a wildly inefficient way of doing things. There was a bug discovered a while back where pinging a link to a large file (a 50MB .avi or .exe, for example) would cause MT to load the whole file (trying to autodiscover whether it could be trackback-pinged!), choke on it, and hang.
posted by reklaw at 2:55 PM on July 15, 2004

Ah! So the linkee system automatically sees a trackback value of some kind the first time a person follows the link from the linker's site to the linkee, at which time the linkee system notices & notes the trackback. ah HA! how complitrated. So if trackback had been turned on, then my link to the post over at H&H in the question above would be construed as a trackback on the H&H end. I think I see.
posted by luriete at 3:12 PM on July 15, 2004

No. It's sort of parallel to referrer logs, but you don't need to click through for it to happen. Think of it as a way for two websites to talk to each other.

Assume Alice and Bob both have trackback-enabled blogs (or whatever. Alice has written something fascinating that Bob wants to blog about, so he does, and creates a link to Alice's entry. When Bob hits the "post" button, his blog automagically tries to figure out where to send a trackback notification (there is also a way to explicitly state where trackback notifications go, but all Movable Type blogs, for instance, can figure this out automatically these days), and sends a message to Alice's blog saying "Hi, Bob wrote this about your entry Such-and-Such. Alice's blog responds "Oh, thank you, I'll make a note of it."

See: a beginner's guide to trackback
posted by adamrice at 3:42 PM on July 15, 2004

Thanks. Now I understand: it is MAGIC.
posted by luriete at 5:06 PM on July 15, 2004

The confusing part is that MetaFilter threads have an automatic trackback URL that Typepad probably found for you, but that I'm not currently displaying trackbacks on MetaFilter after a few people abused it.

So when you made your post referencing the MetaFilter post, it should and probably did send a trackback over here. If I enabled the display of tb, you would have seen a link to your site.
posted by mathowie at 5:57 PM on July 15, 2004