We’ve been getting complaints about seeing duplicate posts in some feedreaders (and I’ve seen this myself several times at Planet Ruby on Rails). We like our subscribers and don’t want to piss you off!
Does anyone know what causes this? We are using FeedBurner with Mephisto (approximately version 0.8) and producing Atom. The feed validates.
Our guess is that it has something to do with updating the posts, but we’re not sure. It may also happen when updating the permalink (which I encourage my co-authors not to do after publishing. Naughty naughty!) On Planet Ruby on Rails, there is sometimes a problem where one copy of the post goes to “www.railspikes.com” and one to “railspikes.com” and one to the FeedBurner post link (example).
We have id, published, updated and link tags to identify each entry:
1 2 3 4 5 |
<id>tag:railspikes.com,2008-04-25:1351</id> <published>2008-04-25T18:57:00Z</published> <updated>2008-04-25T18:57:12Z</updated> <link href="http://feeds.feedburner.com/~r/RailSpikes/~3/277795704/startup-school-2008-misc" rel="alternate" type="text/html" /> |
Any ideas? We’d like to fix this problem.
I’ve been working on implementing my own feed reader (insert shameless plug: feedish.com) for a while now. I noticed the repeat posts from you guys over the last few days as well. The way I check for uniqueness, ie my understanding of how this is supposed to occur, is to use the id as a unique key. In your case, since the id includes the date it might well change on updated (in my opinion the link changing is much less of a problem than changing id. The id should remain globally unique and unchanged). I can’t really speak for other readers, but I think this statement is pretty valid. I would love to hear what you find out though, as repeat posts is somewhat of a common problem and I would love to be able to point to the cause more directly to help others fix it.
I am using FeedBurner and Mephisto too. I also have experienced the double posts. It seems (although I am not sure) there will be double post if you edit and entry after Feedburner has fetched it. That said I am not 100% sure if this is the problem. Should test and see…
I’ve suffered from the doubles in google reader as a user. I’ve noticed that it is usually tied to changes. Edits result in repeats somehow. Also people who redesign their blogs usually cause their entire archive to show up again which makes me wonder since for most of them it should just be css changes.
obvious observation: one of them opens to www.railspikes.com, and the other to railspikes.com…
also dunno if this helps? http://www.xn—8ws00zhy3a.com/blog/2006/08/rss-dup-detection
Nice. My friend just tipped me off that this post is doubling up in Google Reader. And I didn’t even edit it!
I have the post doubled up in Google Reader as well, the two entries have different links:
http://feeds.feedburner.com/~r/RailSpikes/~3/279467374/duplicate-postshttp://feeds.feedburner.com/~r/RailSpikes/~3/279617926/duplicate-postsGoogle Reader is reporting that the first one was 14 hours ago and the second only 10 hours ago.
The Startup School post has four entries in Google Reader each with a different link.