Joe Hildebrand wrote:
On Mar 18, 2008, at 4:25 PM, Pedro Melo wrote:
The repeaters concept doesn't solve the privacy list interactions either.
Why not? For each list of folks that a server wants to send presence
to, it creates a list. If that list has different people on it for
different reasons, it creates different lists. In the case of presence,
the server could, in the face of privacy lists being turned on, create a
presence-out list and a presence-probe list for the user in question at
Typically, presence-out and presence-probe are identical. They are not
in the case of wannabe-invisible, where someone probes his contact, but
does not send presence to them. I love my servers mode for showing
probes and usually remove those people from my roster :-)
each site where you have more than N users, where N should be determined
through some sort of analysis at where the trade-off point is. I'm
betting it's at least 10.
Mh... could be a problem if Peter still thinks that the average user
has no more than 10 users on his whole roster ;-)
I bet that you can lower the breakeven from 10 down to 3, if you
* have a well-known persistent list containing all legitimate
subscribers of your presence
* allow for (at least one) persistent lists composed of subsets
of the former (useful for permanent blocking)
* can start each list from the first list and subsequently remove people
Yes, this could lead to **lots** of lists.
As long as all those lists are subsets of the (synced) roster...
creating lots of arbitrary lists sounds like a use-case for spamming.
> We better a) get the protocol right, b) make sure it's going to help,
> and c) implement it carefully.
Then let me add a tricky use-case for presence which does not
exist in muc and pubsub: the reply to a probe.
Even when you optimize the probes somehow:
Romeo ---> Montague Server ---> Capulet Server ---> Juliet (balcony)
Capulet Server ---> Juliet (chamber)
Capulet Server ---> Nurse
Capulet Server ---> Peter
Capulet Server ---> Sampson
Capulet Server ---> Gregory
Capulet Server (Anthony is offline)
Capulet Server (Potpan is offline)
there is a reply from the people who are online (sow the wind and reap
the whirlwind):
Romeo <--- Montague Server ---> Capulet Server <--- Juliet (balcony)
<--- <--- Capulet Server <--- Juliet (chamber)
<--- <--- Capulet Server <--- Nurse
<--- <--- Capulet Server <--- Peter
<--- <--- Capulet Server <--- Sampson
<--- <--- Capulet Server <--- Gregory
The number of stanzas is lower than the (non-optimized) 'probe storm',
but each stanza is bigger.
We've only been able to solve that by not probing at all.
Philipp
