[Pyro] Newbie Question Regarding Pyro

[John French]

I'm putting together a new project which I'm using to learn Python and have 
questions about pyro. I like the idea of the abstraction that pyro offers 
from sockets programming but I cannot determine if I'm giving up some 
possibly needed functionality.

If the server needs to send an unsolicited ad hoc message to a given client, 
is this possible? (New message or a reminder, for instance) I suppose I 
could poll a server side list from the client but I'm wondering if the 
server can initiate the exchange.

Also, if a client wishes to converse with another particular client (in a 
chat or IM situation, for instance). What's a good mechanism for this?

Does pyro create a persistent client/server connection? What happens if a 
pyro client goes down hard? Does it's process continue or is there a cleanup 
mechanism?

Thanks in advance.