[Standards-JIG] Client Capabilities (rant)

Chris Mullins chris.mullins at coversant.net
Mon Nov 21 08:02:42 UTC 2005

Maciek Niedzielski Wrote:
> > but it doesn't really matter... if the version number 
> > is different, you still have to fetch their features 
> > anyway.

> But this is only one query.

(Just to finish this point)

This is not, and cannot, be true. If a client advertised 10 EXT items,
there MUST be 11 disco info requests. 

Case in point:
Bob's client "Spiffy Client, 1.0" advertises "A B C D E F".
Dave's client "Spiffy Client, 1.0" advertised "Z X Y W".

The first time Eric sees "Spiffy Client, 1.0", he makes a request of:
"Disco Info Node=SpiffyClient#1.0". Given the way the JEP works, Eric
would get back the 3 basic features supported by the client:
"Feature=IQ:Version, Feature=IQ:Time, Feature=IQ:Last".

Eric's client then does disco info for "A", then disco info for "B", and
so on.

Next, Eric's client sees Dave's client, it says, "ah ha!, I've seen this
before" and doesn't bother performing the disco info against the base
node. It does (must) do disco info against "Z", then disco info against
"X", and so on.

This is way more than the "this is only one query" case that everyone
keeps bringing up. 

Chris Mullins

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