Hacker News Reader

Comment by MatthewPhillips | Hacker News Reader

> The “level 0” solution is to periodically fetch each feed, parse it, diff it and hopefully find something new.

Wait, do feed readers really not do a HEAD request first and check Last-Modified ?

I would hope that they wouldn't do it that way; they should be sending a GET with If-Modified-Since. The same result, making half the requests.

I don't think those values are always reliable.

So which is easier, getting servers to fix them to be reliable, or getting everyone to change to a new json pubsubhub whatever thingy, that they'll probably do unrealiably anyway too?

HEAD is still a waste of resources. the http body in the context of feeds is usually pretty small and does not consume a lot of resources compared to actually initiating (or even keeping) the TCP connection. HEAD also means the server as to do everything but send the data to make sure it does not need to sent it => waste.

HEAD also means the server as to do everything but send the data to make sure it does not need to sent it

Not at all. If you have the RSS as a static file - and that's the best way for a resource that is much more often read than written - the web server can just stat() the file and get the modified timestamp instead of having to open and read it.

Show me a service that has static files as RSS :) no matter what a stat() is still more expensive than nothing

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