On 3/2/12 6:53 AM, "Kevin Smith" <[email protected]> wrote:
> On Thu, Mar 1, 2012 at 2:13 AM, XMPP Extensions Editor <[email protected]> > wrote: >> Version 0.1 of XEP-0312 (PubSub Since) has been released. > > I have two main problems with this, the first is that using > timestamp-equivalents isn't a reliable way of syncing things on the > network. We have this approach in XEP-0045, and it results in > duplicates quite a lot of the time (without the added buffer period in > 312) I suspect it also results in missed messages, although I've > clearly never seen them. The buffer period makes missed messages less > likely (although still possible), but increases the chance of > duplicates. It's not clear to me that this isn't harmful. I don't see that as a large problem in pub/sub, since a later publish with the same ID replaces the previous publish. As long as the receiving server backs up enough to deal with reasonable clock skew, the worst case is a small number of republishes, which is usually going to be much better than a full synchronization, and is never going to be worse. > The second is that there are many other times a pubsub service will > receive delay inside a presence, and this proposal could result in > duplication within a single stream. A) Let's change the namespace then. B) It may be that all of those times are at initial login, in which case there's no need to change the namespace. -- Joe Hildebrand
