Discovery of other peers

[Mario Pichler]

Hi all,

How does the discovery of other peers (agents, hosts)  work and how can I get informed about the arrival of other peers?

Why is it necessary to declare one peer as leader?

Thanks a lot,
Mario

[Radu Handorean]

The version of Lime that you're using does not support automatic engagement and discovery of other peers, as you call them. This is simulated using the engage() method of the LimeServer. Recently we developed a package that eliminates this extra step and provides automatic engagement based on location information. I didn;t personally worked on this package but I'm sure the author will contact you about this. The leader is used for the implementation of the engagement protocol. To discover the arival and departure of oterh peers, you can look into LimeSystemTupleSpace. Check the documentation about this particular (system maintained) tuple space. I think it contains all you want to know.
  Hope this helps.
  Radu

[Amy Murphy]

Just to add a little info to what Radu already wrote:

It is correct that the version of Lime on SF requires you to initially specify a host leader.  This allows other hosts to successfully call the LimeServer.engage() method.

The declaration of a leader is only an initialization step, and should not affect the rest of the running of your application.

To watch for the arrival and departure of agents and hosts (what I assume you are referring to as peers), you should use the LimeSystemTupleSpace (LSTS).  There is an example of how to do this in the examples directory (InteractiveMonitorAgent.java).

When a host/agent engages using LimeServer.engage or lts.setShared(true), the LSTS will be affected.

If you have any question about why the leader is needed, please read the documentation and/or write again to this list.

-Amy