[Nel] Suggestion for the NeL network library / architecture

Tue, 12 Dec 2000 11:08:20 +0100

According to Jean-Noel Moyne:
+> You should have a look at PGM, which is an open reliable multicast
+> protocol designed by Cisco and TIBCO (the company I work for), which is
+> design to solve just this kind of problems in the most efficient way.
+
+Hmmm, about everyone around started talking about, then dismissing it
+as unsuited to our needs, but that's chiefly due to one misunderstanding.
+
+At first we didn't see the "server to server" sentence.
+
+We still don't know how well multicasting can be useful in our server
+architecture, because so far, we have very few one-to-many messages
+across servers. Most services discuss with a specific target on a specific
+service.
+
+However, we still have lots of discussion for the "world service",
+i.e. the service which "simulates" the world and run the various objects
+and NPC agents. That one might be a candidate for a multicast protocol,
+since we can expect replication of objects across multiple world services.
+
+This tie in with another question which I didn't had time to reply to,
+regarding how to "split" the world across the multiple world services.
+If the split is done by geography (the UO model), then there is little
+need of a PGM-based protocol, because most objects will be accessed by
+2 world services (edges), or at most 3 (T-intersections). However, if the
+split is done instead by reference (i.e. we cluster an agent with the
+agents that refer to it more often), then we have a higher redundancy
+of agents on servers, and a multicast is probably the best method to
+send message to these agents.
+
+-- 
+Vincent Archer                                         Email: archer@nevrax.com
+
+Nevrax France.                              Off on the yellow brick road we go!
+
+