[Standards] MIX-PAM: private PEP node for joined channels

Matthew Wild mwild1 at gmail.com
Mon Dec 9 10:39:17 UTC 2019

Hi Jonas,

A couple of observations about your post follow below, though not to
say I agree or disagree with your overall position (I need to think
about this issue more).

On Mon, 9 Dec 2019 at 10:12, Jonas Schäfer <jonas at wielicki.name> wrote:

> 1. Current state of archiving in PEP

> So the state transfer must be initiated by the client (with the client telling
> whichever entity keeps the history what its last state was). This is like
> roster versioning.

Yes, something like roster versioning for pubsub would be interesting
in general.

> This could be via a MAM archive which holds the notifications of the PubSub
> node (either the user’s archive, but see what Holger said, or an archive on
> the PEP node itself, which is unheard of so far, as far as I know). [...]

Yes, unheard of as far as I know. It would be tricky because PEP nodes
don't have their own JID, a PEP service uses the user's JID (which
typically already has a MAM archive).

> [...] Note
> however that MAM silently treats the case of "the last stanza you saw expired
> from the archive" as "fetch everything since beginning of archives", which
> means you won’t notice that you lost notifications when using MAM (with
> expiry) for sync.

It's true that originally there was no error specified in this case,
but that's not the case in the latest version of the XEP:


More information about the Standards mailing list