RSS: update frequency?

Question

I am writing a small application for my own use that will consume a publicly published RSS feed.

As far as I can tell, there is no subscription / message mechanism in the protocol; I need to periodically update the HTTP-GET RSS application.

If this is the case, I would like to grab it every ten minutes or so, but I worry about being treated as an offender. Of course, I would be worried if I saw that someone poked my server every ten minutes for several weeks in a row.

Is this a valid issue? Is there any general advice on what a “reasonable” refresh rate is? Do I even have my facts straight?

Answer 1

Since RSS is built on the HTTP protocol, in most cases most sites should respect the If-Modified-Since HTTP header. This is a fairly light weight, and most servers should be able to quickly return this information.

So, for the client side, you will need to track the last time you sent a request and transferred it to the server. If the server returns code 304, you will find out that nothing has changed. But more importantly, the server does not need to return channel information while storing traffic bytes. If the server returns 200, you need to process the results and save the response date.

Ultimately, the answer to this question depends on what type of information is on the other end of the RSS feed. If this is a blog, then probably once every 4-8 hours. But if the RSS feed is a source of stock quotes (most likely, just an example), then every 10 minutes is not enough.