Industry guru Dave Taylor offers tech support on technical and business topics, including iPhone, iPod, Microsoft Windows, Sony PSP, cellphones, online advertising, CSS, Web design, business, Unix, Linux, SEO, Mac OS X, and shell script programming.     


Why does my RSS aggregator show me stale news?

I notice once in a while in my RSS aggregator that I am getting feeds that are sometimes 2 months old. Why would the aggregator be lagging on such stale news.


Dave's Answer:

Y'know, I've noticed that this happens too with some frequency on my RSS reader, NewsGator, and I decided to dig into it a bit to find out what's going on.

It turns out that the algorithm that RSS readers or aggregators use to figure out what snippets of news you haven't seen is pretty simplistic; it's all based on whether the last modification date is more recent than the last time you read the news from that site. Ordinarily, that'd work perfectly because just as with a newspaper, once an RSS feed from a Web site or weblog adds a new item, it never changes and you only see it once.

But what do you think would happen if the site administrator is monkeying with the backend software that generates the feed and changes a seemingly irrelevant HTML tag within the RSS feed from, say <br> to <br />? If you're thinking that the last modified time changes, then you're exactly right.

In fact, that's mostly what happens when older RSS articles are presented as new content again, as far as I can ascertain.

Of course, some RSS feed authors will actually go back and modify older articles too, perhaps adding a forward link to a newer article on the subject, fixing a broken URL, or engaging in a little bit of historical revisionism. In all those cases, the entry in the RSS reader will appear again, even if it's weeks or even many months old.

Finally, when a site with an RSS feed, particularly a blog site with its feed enabled, moves to a new server or a new version of its backend software, every file on the server is 'touched' and will then have a newer last modified date. Therefore, every entry in the feed suddenly appears in your RSS reader for no apparent reason.

At this point in time, it's just the way the system works. Since some sophisticated RSS readers (notably NetNewsWire) actually archives RSS data so it can show you change marks and you can see how a specific entry in an RSS feed evolves over time, it's theoretically possible for these same readers to suppress the presentation of redundant RSS entries entirely.

Hope that helps clarify things!

If you'd like more information about Really Simple Syndication and how to work with it, I also have a variety of different articles available on this topic, which you can find by searching for RSS information on this site.


More Useful Blogs and Blogging Articles:
✔   Get my shopping cart plugin to work with WordPress?
We've put in a shopping cart for a client that's not working, and we need some help! The cart is currently using the...
✔   Embed an audio player on a blog or web page?
I have some mp3 audio files I've recorded and would like to have people who visit my site be able to listen to...
✔   Can I write a guest review for AskDaveTaylor.com?
Hi Dave. I'm a big fan of your site and love that you're doing so many reviews now. I've noticed, however, that there...
✔   Change author on WordPress blog post?
I have two accounts set up for my WordPress blog and I'd like to be able to have all my posts from a...
✔   How do I restructure my Wordpress blog without losing SEO?
I have a wordpress blog that was using categories in the url structure like this: /category_name/post_name/ Then I had read somewhere that if...

Let's stay in touch!
Sign up for my weekly AskDaveTaylor Newsletter and you'll receive even more tech and gadget help right to your inbox, along with exclusive news and industry updates. It's good stuff. I promise!
    Enter your name: and your email addr:  





Categorized: Blogs and Blogging   (Article 4245, Written by )
Tagged:
Previous: What is ASP.NET?
Next: What is Google Base?




Reader Comments To Date:

Starbucks coffee cup I do have a lot to say, and questions of my own for that matter, but first I'd like to say thank you, Dave, for all your helpful information by buying you a cup of coffee!
Rather amazingly, there are no comments on this article yet.

I do have a comment, now that you mention it!











I will never send you any unsolicited email. Ever.






Check This Out Too...

 
Look for Answers
Need Help? Ask Dave Taylor!


Follow Me on Pinterest

Find Me on Google+
ADT on G+
© 2002 - 2013 by Dave Taylor. All Rights Reserved.

Note: This web site is for the purpose of disseminating information for educational purposes, free of charge, for the benefit of all visitors. We take great care to provide quality information. However, we do not guarantee, and accept no legal liability whatsoever arising from or connected to, the accuracy, reliability, currency or completeness of any material contained on this web site or on any linked site. Further, please note that by submitting a question or comment you're agreeing to my terms of service, which are: you relinquish any subsequent rights of ownership to your material by submitting it on this site. My lawyer says "Thanks".
"Ask Dave Taylor®" is a registered trademark of Intuitive Systems, LLC.