[Standards-JIG] Dead participants in MU-conf, JEP-0045

Justin Karneges justin-keyword-jabber.093179 at affinix.com
Thu Dec 16 07:14:57 UTC 2004

On Thursday 16 December 2004 03:54 am, Jacek Konieczny wrote:
> On Wed, Dec 15, 2004 at 02:01:50PM -0500, Justin Karneges wrote:
> > This would be great, and it is what I was advocating also, except that it
> > appears to violate the protocol:
> >   http://www.xmpp.org/specs/rfc3921.html#presence-resp-probes
> >
> > 'If the user is not in the contact's roster with a subscription state of
> > "From", "From + Pending Out", or "Both" (as defined under Subscription
> > States), the contact's server MUST return a presence stanza of type
> > "error" in response to the presence probe...'
> So _that_ error should be ignored. But all the "timeout" and "connection
> failed" errors still could be processed as proposed.

For MUC this it not enough.  MUC exists in the abstract world of Jabber, and 
availability of an s2s connection doesn't necessarily mean anything.  If the 
s2s link comes back up, but the client has since left the room, how can the 
MUC know this?  It will keep sending presence packets, and possibly even 
messages, without receiving a bounce.  The ability of the MUC's server to 
probe for a participant's direct presence would allow the MUC to really know 
if the person is still considered to be in the room.

From your other mail:

> What about the s2s connections coming back to life?
> How much additionall processing and resource usage will that require
> from the servers?
> What about distributed servers, with multiple s2s and other components?

While I'm no server developer, the procedure for handling probing of direct 
presence would appear to be the same as that of subscribed presence.  So it 
should not be that difficult to incorporate.


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