Archive for December, 2006

It's always fun when a story hits the blogosphere while you're stuck on a plane. :)

This will be short, because I'm connecting over a 14.4K modem line (I have the deepest sympathy for folks who still do this every day!), but I just want to say a few basic things about the RSS-related patent applications mentioned in the article and elsewhere.

First, these patents describe specific ways to improve the RSS end-user and developer experience (which we believe are valuable and innovative contributions) -- they do not constitute a claim that Microsoft invented RSS.

We have always fully acknowledged the innovators and supporters of RSS, like Dave Winer, Nick Bradbury and many others, and I can say, without hesitation, that I and my colleagues personally have the deepest respect for their invaluable contributions.

From the beginning we have sought an open and reasonable relationship with the RSS community. As one example, we have published various RSS and Atom extensions under a Creative Commons license. These specifications provide proof of our commitment to offer our contributions to the community and evidence of our efforts to advance the technology. We honestly hope that our work brings benefit to all feed publishers, developers and users, and we've been happy with the response we have received from the community so far.

Finally, as a number of commenters have noted, we are far from the only company to apply for patent protection in this space. Other companies, including Apple and Google, have apparently also applied for patents. Applying for a patent on your innovation is common industry practice, and one which, by incenting and protecting the companies and people involved, encourages everyone to contribute to the community.

I hope this helps put our position in perspective. I want to reiterate that my team and I are fully committed to RSS and feed syndication technologies in general and to the community. Please post any additional questions (I'm sure you didn't need an invitation :), and I'll get back to them in the new year.

Thanks,

Sean Lyndersay
Program Manager Lead, RSS

Warm messages from the soldiers' hearts to their loved ones. Happy Holidays everyone!












Please click here for more Holiday Greetings!

8 videos to celebrate the 8 days of Hanukkah!

The Comedy Time Network began in 1994. Today, it's become a leader in original comedy content created especially for wireless handsets. Comedy Time is available on Sprint, Cingular and Amp'd and is distributed worldwide -- so you can laugh wherever you are.

Today's Highlighted Videos

Here at Google Video, we like footage of dogs acting goofy as much as the next aggregators of online videos -- and if the canine clips in question also involve doggie antlers, little red Santa outfits, and the promotion of a feel-good Google product launch, well, all the better.

Calling all Good Charlotte Fans! You've seen the video for "Keep Your Hands Off My Girl," now they want to see yours! Good Charlotte encourages you to make your own "Keep Your Hands Off My Girl" video. This is your chance to get behind the camera and create your own version. The best video will be chosen by the band who will call you personally to talk with you about it, feature it on GoodCharlotte.com, AND hook you up with a signed guitar!

To enter, please visit http://goodcharlotterocks.com/googlevideo/. Hurry, deadline is this Friday 12/15.

XOS Technologies brings you, the fans, sports content from more than 750 teams in the NFL, NBA, NHL, MLB, and more. Whether you're a football fanatic or a puck bunny - you'll find it here on Google Video.

A Widget to track the care and maintenance of any or all of your vehicles.

To track multiple cars, simply spawn another instance of this Widget. You can also just copy and rename this Widget file and open it again with Konfabulator. For example, make three copies of this Widget, and name them after your cars: My Civic.widget, My Thunderbird.widget, etc.

Note: Default maintenance schedule is an approximated generic maintenance schedule pulled from the AAA website. (http://www.aaa-calif.com)

Features:
- Prioritized maintenance task reminders
- Customizable maintenance schedule
- Several other customizable features


Version History
1.29 - Long-overdue maintenance update
1.28 - Finally did away with the car getting "dirty"
- Also finally added ability to change the picture
1.27 - Added a mainenance status icon
1.26 - Decided to support the metric system
1.25 - Interactive car graphics added
- Additional preferences added
1.0 - First release

A while ago I posted details about the RSS Platform Download Engine. That post focused on downloading of feeds, but did not include additional details on enclosure downloads.

   

Enclosures are, as most readers know, files that are "attached" to items in an RSS feed. Typically, a publisher will include a reference to a binary file, which an RSS aggregator can optionally download when the feed content is downloaded. The most common example of enclosure use in RSS feeds is for podcasting, where the attached (or "enclosed") files are audio files.

   

As with feed download, we designed the enclosure download with server and client bandwidth in mind since feed as well as enclosure downloads also happen in the background. Their impact on foreground applications should be limited. Similarly, the impact of large enclosure downloads on servers should be limited.

   

Let me sketch how the enclosure download process works:

1. Every time the feed download engine runs it processes feeds that have the "Automatically Download Enclosures" setting set to true it. If it comes across a new item with an enclosure it adds the URL of the enclosure to a FIFO queue.
2. Before the enclosure is added to the queue, the URL is checked with Attachment Execution Service API (AES) to assure the enclosure file type is one of the permitted types. If it's not, the enclosure download is failed (IFeedEnclosure.LastDownloadError = FDE_DOWNLOAD_BLOCKED).
3. The first 4 enclosures in the queue are then handed off to the Background Intelligent Transfer Service (BITS). BITS is a background download service that ships in Windows and which enables downloading of files in the background while limiting its affects on network usage. In particular, BITS uses HTTP RANGE requests to download files in chunks. BITS also monitors whether foreground applications (like email or browser) are using the network, and if so, it throttles back its own network usage to limit its impact on those applications.
4. Once BITS completes downloading an enclosure, the Download Engine uses AES to save the enclosure to the folder corresponding to the feed. Saving via AES associates zone information with the file. The zone information is used when the file is launched at a later time.
5. If there are more enclosures waiting to be downloaded and there are less than 4 enclosure downloads active, the next enclosure is handed off to BITS as in step #3.
6. If, however, the server of the enclosure does not support HTTP RANGE requests, the Platform Download Engine falls back to downloading the enclosure via a regular HTTP GET request. If this attempt fails as well, then the enclosure download is fails and will not be attempted again automatically.

      

Note that the enclosure fall-back download (HTTP GET) is size limited to 15MB to limit the impact of denial of service (DoS) attacks against the RSS Platform Download Engine. Since the RSS Platform Download Engine runs in the background, a malicious server could consume all of the client's download bandwidth without the user having any idea. Enclosure download via BITS (HTTP RANGE requests) is less impacted by such an attack and is consequently not size limited.

   

In other words, if you are an enclosure publisher that wants to serve enclosures larger then 15MB to IE7 users, then you should use HTTP servers that support HTTP RANGE requests. Most popular web servers support HTTP RANGE requests.

   

It's also worth noting, that when a server does not support HTTP RANGE requests, the RSS Platform Download Engine will issue two requests for each file (the first testing for HTTP RANGE support, and the second to download the file without range support).

For more details on the security measures used to protect applications and users from potentially malicious enclosures, see Miladin's enclosure security post.

   

I hope that this description of the enclosure download process explains the "multiple-requests" that some publishers have seen, as well the security restrictions associated with enclosure downloads.

   

-Walter vonKoch

Program Manager

I was going to try and impress you with my pigskin trivia *cough*search for football facts on Google*cough*, but I decided not to fake it and fail miserably. So, I'm just going to let these videos and the pros do all the talkin'!

Happy football season!








Find more football fun at the Rivalry page!