[Nel] Dynamic load balancing?

Mon, 19 Feb 2001 17:04:15 +0100

According to EagleEye:
+> I would love dynamic load balancing... just add another server to your
+> cluster, and assign it a piece of the game world to take care of... perhaps
+> that city area that just got really popular in the last few weeks...
+
+That's not dynamic load balancing if you have to assign servers to a
+specific area. That's merely 'reconfigurable static' :)
+
+Ultima Online did this for their servers. They measured during beta
+a lot of statistics, and created a map of areas for allocation to all
+processors (server being ambiguous here, because their servers were
+multiprocessor boxes). That map could be redone at will, depending on
+the number of processors allocated to a shard. But once the shard was
+started, that was it. The only way to add a processor would be to
+split one area in two, and the whole migration process was hard
+enough that it wasn't worth (their words) the development cost vs the
+number of times it would be used.
+
+True dynamic load would mean that each processor would adjust its
+border (i.e. which objets it manages) according to its load, compared to
+its neighbours. If it has too high a load, then its border would shrink
+along its most lightly loaded neighbour, swapping objects between one
+and the other.
+
+Of course, that means a variable, almost fractal geometry of processors,
+and a processor that, at boot time, was serving city A and its adjacent
+areas could well, four days later, be serving chiefly the mountain range
+5km from there, because of simple "pressure". It looks nice from a
+strict research standpoint, but it's HELL for system management.
+
+-- 
+Vincent Archer                                         Email: archer@nevrax.com
+
+Nevrax France.                              Off on the yellow brick road we go!
+
+