[Nel] Dynamic load balancing?

Wed, 21 Feb 2001 11:21:23 +0100

According to Thierry Mallard:
+> On Tue, Feb 20, 2001 at 11:21:38AM -0300, Nahuel Greco wrote:
+> > [... case of zone server failure ...]
+> > Then, you has the map divided in zones,... if a geographic server dies, other
+> > will be taking the zone that belong to the died server? .. 
+> 
+> The problem here will be persistency (is that english ? ;-). All the data
+> currently in memory on server A, which is failing, will be lost for server B
+> which is supposed to take over.
+
+That's what you get with a purely geographic design, like EQ/UO design.
+When a zone fails, you get kicked out, everything you gained since your last
+save is lost, and when you return, every single critter has respawned. All
+state is lost, since all state was located in a single process.
+
+With a functional approach, all game entities are "holographic"
+regarding to storage. They're a kind of "cloud" of various agents located
+on various services. If a geographic server dies, you get suddendly
+a kind of fog for a while. Another service starts up, gets back information
+about what critters are where from the AI services, where all players are
+from the various player services, and what items are grown where from the
+ecology services. It takes a little time, but you recover more
+gracefully.
+
+The same occurs if an AI server dies. Those critters that were managed
+by that service freezes, but then another service takes them over. They
+will probably forget a lot of what they were doing, but they don't "depop",
+since the geography service knows that there's that kind of beast
+that was located there.
+
+Of course there are services that are more critical than other. If a login
+service dies, all players using it are kicked out forcefully. If the
+item manager dies, your inventory locks up completely (but you still look
+like yourself, can move around, and talk).
+
+-- 
+Vincent Archer                                         Email: archer@nevrax.com
+
+Nevrax France.                              Off on the yellow brick road we go!
+
+