I had a few more thoughts on the Cloud interface that appeared in the RSS 2.0 spec, so I'll lump them together in this post.

* First, I just checked the spec, and it doesn't state that subscriptions expire every 25 hours, but another document (which the spec links to) does state that "by convention", subscriptions expire every 25 hours. That should probably be included in an official specification document.

* Second, while 25 hours is a good default expiration time, it would be nice for a feed to be able to specify its own expiration period.

* Third, when a client receives a notification from a cloud, it simply returns true. Perhaps it could return some value to say "thanks, I got it", and another value to say "thanks, I got it, and by the way, please renew my subscription now." I imagine the line of reasoning behind the way it works now is that anyone who wants to keep subscribing can have a cron job or similar process run once a day to renew their subscription. That will probably work for the majority of cases, but especially if feeds are allowed to specify their own subscription periods, I can imagine situations where enabling a client to renew their subscription upon notification would be preferable.

A change like this would require one change for clients--rather than simply running a cron job every day to renew their subscription, they'd need to either reschedule themselves to renew in 24 hours (or however long) whenever they received an update, or keep track of when they last received an update so that when they were asked for the latest news, they could know whether their subscription had expired, requiring them to re-fetch the feed and resubscribe.

Such a change would reduce bandwidth requirements by reducing the number of subscription requests sent, and reducing bandwidth used by clients who were using the updates. For example, if a web page is displaying a feed from another site, but no one ever visits that page, then there's no need for the page to be updated. If someday it was viewed, it could see that it hadn't received an update for a long time, explicitly reload the feed, resubscribe, and be done with it till the next visitor happened by.

Reader Comment:
Pauldon said:
Is there any other possible areas that the Cloud interface could be improved?
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