How to get up to date information from Discovery
So imagine we've got our peer group up and running with a number of peers connected (from different parts of the internet) to a single rendezvous.
In this group, peers want (NEED, in fact) to know if another peer has left the group so they can notify users, however, when a peer leaves the group, there is no guarantee that they'll be able to notify anyone eg. due to power failure...
So my question is, how does one maintain a reasonably up to date list of which peers are online or not?
I'm aware that one can set the expiry time of an advertisement, possibly to quite a short interval... eg 10 seconds... and then republish every 8 seconds... but is this feasible? I don't imagine this sort of scheme would scale to well.
Does anyone know how the guys that built jxta invisioned something like this working?
Has anyone had to deal with something similar? eg in a chat application