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diff --git a/pipermail/nel/2000-December/000081.html b/pipermail/nel/2000-December/000081.html new file mode 100644 index 00000000..cc2d1ea2 --- /dev/null +++ b/pipermail/nel/2000-December/000081.html @@ -0,0 +1,95 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> +<HTML> + <HEAD> + <TITLE> [Nel] Suggestion for the NeL network library / architecture</TITLE> + <LINK REL="Index" HREF="index.html" > + <LINK REL="made" HREF="mailto:archer%40nevrax.com"> + <LINK REL="Previous" HREF="000080.html"> + <LINK REL="Next" HREF="000082.html"> + </HEAD> + <BODY BGCOLOR="#ffffff"> + <H1>[Nel] Suggestion for the NeL network library / architecture</H1> + <B>Vincent Archer</B> + <A HREF="mailto:archer%40nevrax.com" + TITLE="[Nel] Suggestion for the NeL network library / architecture">archer@nevrax.com</A><BR> + <I>Tue, 12 Dec 2000 11:37:00 +0100</I> + <P><UL> + <LI> Previous message: <A HREF="000080.html">[Nel] Suggestion for the NeL network library / architecture</A></li> + <LI> Next message: <A HREF="000082.html">[Nel] Suggestion for the NeL network library / architecture</A></li> + <LI> <B>Messages sorted by:</B> + <a href="date.html#81">[ date ]</a> + <a href="thread.html#81">[ thread ]</a> + <a href="subject.html#81">[ subject ]</a> + <a href="author.html#81">[ author ]</a> + </LI> + </UL> + <HR> +<!--beginarticle--> +<PRE>According to MIGUEL ANGEL BLANCH LARDIN: +><i> > At first we didn't see the "server to server" sentence. +</I>><i> +</I>><i> Ok, I have a dummy question, but when it is better to have multicast +</I>><i> to a server delivering the messages to the rest of servers? +</I> +Quite simple: When you need to send the same message to more than one +server. As soon as you need to send a message to multiple servers, +you will tie up bandwidth and CPU resending the same message over and over +to each server. + +Consider the following model. Each agent (which represent an object, NPC, +PC, the door, the lamp, whatever entity in your world) is represented +typically by an object in a "world service process". Once your world +becomes large, you need multiple processes. What happens when an agent +want to "talk" to another agent on a different process. The agent, in an +ideal (and OO) world, merely talks to an object located in its process +space, said object being either the recipient agent itself, or merely a +replica, which will forward the message across the network to the real +agent. + +You don't need multicast for that: its straight 1-to-1. + +However, what if the message is "what is your current XYZ". That's a fairly +frequent question. If you need to query across the network, you'll quickly +end up loading the net, just to find the value three variables. + +That's where PGM/multicast intervenes. In that model, the agent, when he +changes some of his variables, notifies the replica that "XYZ are now...". +I spoke about how the world services organise where an agent resides. In +some models, you have about one, maybe two replicas, which you can notify +using a standard TCP stream. Or RDP. But, if you want a load-balancing +system, you quickly end up with a replica of an object in most world +service processes. It becomes then more efficient to multicast the updates +as above to all processes, and update them all in one sweep. + +><i> How portable/compatible is mulitcast technology? +</I> +Multicast is working, right now. However, to work across separate networks, +it requires specific support from IP routers, and resources, which most +providers aren't willing to dedicate (multi-network multicast is mostly +used for video/audio "broadcasts", video conferencing or shows). + +As for PGM, well, the current library has lots of empty directories and +"TODO" notes in comments, so it's clearly a work in progress :) + +-- +Vincent Archer Email: <A HREF="mailto:archer@nevrax.com">archer@nevrax.com</A> + +Nevrax France. Off on the yellow brick road we go! + +</pre> + + +<!--endarticle--> + <HR> + <P><UL> + <!--threads--> + <LI> Previous message: <A HREF="000080.html">[Nel] Suggestion for the NeL network library / architecture</A></li> + <LI> Next message: <A HREF="000082.html">[Nel] Suggestion for the NeL network library / architecture</A></li> + <LI> <B>Messages sorted by:</B> + <a href="date.html#81">[ date ]</a> + <a href="thread.html#81">[ thread ]</a> + <a href="subject.html#81">[ subject ]</a> + <a href="author.html#81">[ author ]</a> + </LI> + </UL> +</body></html> |