On Sat, 28 Feb 2009 15:18:38 +0500 Waqas Hussain <waqa...@gmail.com> wrote:
> On Thu, Feb 26, 2009 at 9:32 AM, Pedro Melo <m...@simplicidade.org> > wrote: > > > > On Feb 25, 2009, at 7:36 PM, Pavel Simerda wrote: > > > >> On Tue, 24 Feb 2009 15:54:38 +0000 > >> Pedro Melo <m...@simplicidade.org> wrote: > >> > >>> Hi, > >>> > >>> On Feb 24, 2009, at 12:49 AM, Pavel Simerda wrote: > >>> > >>>> There are several cases when subscription databases in XMPP are > >>>> inconsistent. > >>>> > >>>> You may view subscription information as a global distributed > >>>> database. > >>>> Subscription state between two JIDs, for example a...@a and b...@b are > >>>> stored > >>>> in two places at the same time. Servers A and B maintain their > >>>> own copies of subscription state. > >>> > >>> [....] > >>> > >>>> What with the roster items that are inconsistent? > >>>> > >>>> * Mark as inconsistent, let the client present it to the user to > >>>> take action. > >>>> > >>>> * Auto-repair and thus maintain consistency > >>>> > >>>> Looking forward to all feedback. > >>> > >>> When you send out a <presence type="probe" /> include the local > >>> "view" of the subscription state. > >> > >> Btw presence probe seems too weak... as it doesn't reveal full > >> subscription state. > > > > that's what I'm saying: include the full subscription state in the > > presence probe so that the other side can detect mis-matches. > > > > Best regards, > > > > > > I'm considering doing this in Prosody: > <presence type="probe" from="m...@myhost.com" > to="y...@yourhost.com"><item subscription="both"/></presence> > > It wouldn't break anything. I don't see any privacy issues. And it > would give the receiving server a chance to detect any inconsistency. > If there is an inconsistency, the receiving server can take an > appropriate action. > > What action is appropriate is open for debate. What should the > resulting state be? The lowest common permissions (possibly sending > unsubscribe[d] to the contact or changing the user's subscription for > contact)? The highest common permissions (possibly sending a > subscrive[d] to the contact and changing the user's subscription for > the contact)? > > From an IM user's point of view, trying to settle on the highest > common permissions seems more appropriate (and less confusing). Very bad idea. You have either to go for lowest... or negotiate with the user. (Privacy issues) Pavel > -- > Waqas Hussain -- Freelance consultant and trainer in networking, communications and security. Web: http://www.pavlix.net/ Jabber, Mail: pavlix(at)pavlix.net OpenID: pavlix.net
