Re: PP8: Asynchronous change notification for HTTP-based resources

Simon Leinen <simon.leinen@switch.ch> Sun, 20 January 2008 18:31 UTC

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To: Rohan Mahy <rohan@ekabal.com>
Subject: Re: PP8: Asynchronous change notification for HTTP-based resources
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From: Simon Leinen <simon.leinen@switch.ch>
In-Reply-To: <C84985D1-E485-4C6B-997D-9D7DB7286F95@osafoundation.org> (Lisa Dusseault's message of "Fri, 18 Jan 2008 11:00:57 -0800")
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Date: Sun, 20 Jan 2008 19:31:52 +0100
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> Asynchronous change notification for HTTP-based resources
> Rohan Mahy
[...]
> Current practices in change notification involve polling individual
> HTTP resources, or polling some kind of HTTP "catalog" resource to
> see what resources have changed. Both of these methods inherently
> suck.  The "catalog" approach at least substantially reduces the
> number of resources that need to be polled, but the amount of time
> to wait between polls is always one-sided compromise and rarely
> optimal for response time, network usage, and battery life.

FYI, there are a few interesting techniques to make server-to-client
notifications over HTTP more efficient.  The buzzword for this is
"Comet", and the Wikipedia article has good descriptions on some of
these techniques, e.g. "long polling":

http://en.wikipedia.org/wiki/Comet_(programming)
-- 
Simon.