a couple of weeks ago i blogged about our rather sobering tests with real avatars and that we run into serious trouble round about the 21 avatar mark. alan webb, arthur valadares, and i started looking at the what could possibly be biting us there.

having profiled opensim (albeit briefly, you end up with lots of data), arthur had found out that a lot of time was spend in the packet handling code, so we concentrated on the packet and textures handling — hypothesis #2 being that the on-rush of avatars trying to log in all at ance (and being logged in almost all at once) was causing a massive spike in textures demand: alan “outsourced” the texture handling to a thread of its own instead of having it part of the normal packet handling. arthur and i were successful in getting rid of a number of short-lived mass object instantiations.

the result: well, with even more vicious bots (20 of those new ones were sufficient to bring opensim to a stand-still now, similar to real avatars) we now managed to go up to 40 avatars! sure the region became laggy, but, and that is important, we could still use the in-world tools, could still move around, chat and work.

so, progress. now to figure out why massive amounts of collision events reported via LSL cause a deep ODE physics engine crash…