[core] core-interfaces: rationale behind resource observation *attributes*
chrysn <chrysn@fsfe.org> Tue, 23 April 2013 00:39 UTC
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Date: Tue, 23 Apr 2013 02:39:31 +0200
From: chrysn <chrysn@fsfe.org>
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Subject: [core] core-interfaces: rationale behind resource observation *attributes*
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hello, draft-shelby-core-interfaces-05 introduced a modification to the observation parameters, where observations that would in -4 look like this: > Req: GET Observe /s/temp?pmin=10&pmax=60&st=1 > Res: 2.05 Content Observe:0 (text/plain) > 23.2 would turn into this: > Req PUT /s/temp?pmin=10&pmax=60&st=1 > Res: 2.04 Changed > > Req: GET Observe /s/temp > Res: 2.05 Content Observe:0 (text/plain) > 23.2 this seems to be a modification for the worse, for it introduces a global state on the server (which previously resided in the observe subscription that is stateful by design). if two subscribers connect, the second will overwrite the observation parameters the first configured. if the intention is that the parameters that are configured at connection time stay valid for the connection, that's still open for race conditions. what was wrong with the old solution, and why was the new one chosen to supersede the old one? best regards chrysn -- To use raw power is to make yourself infinitely vulnerable to greater powers. -- Bene Gesserit axiom