[vworld-tech] Maximum Latency?

[bradley newton haug]

Jim Wrote:

>What are the average and maximum latencies graphical virtual worlds should
>expect to deal with?

>What do we do when latency gets high? Kick players? Let them play on and 
>let them be the judge of when things get too bad? I can see that someone
>standing in a town chatting to friends can deal with arbitrary latencies,
>whereas that player might have no chance in a fight.

>Should all game systems be designed to deal with high latencies?


When studying various live offerings one can learn from their varied and
well thought out approaches

1.  Ignore it, eventually users won't notice that walking into town means
sputtering graphics, sporadic spurts of text and stuttering sound, and
deaths due to lag are worn as proud scars given names like 'lag tax'.

2.  Blame the user (after all, your network design/ecopolitical
microcosm/load balancing is perfect)

3.  Blame the Europeans (if in America)

4.  Blame the Americans (if anywhere else)

5.  Plan for it (this revolutionary and heretical idea has yet to surface)


Joking aside, a few things you can do to combat the problems lag causes is
how you deal with client commands...  if the person is attacked have him
autorespond on the server without first checking with the client. 

 If he's running somewhere and you lose touch with the client stop him..
i.e. run should be a killswitch that is kept on by a live client, nothing
sucks worse than taking 2 steps into the 'Dungeon of uberdoom', hitting a
lag spike(server related) and waking up dead underneath 'King Woopass' 2
days before the next raid.

Find out what you think your servers can take, try it, and then back it off
accordingly.  Find out what actions and whatnot are causing any badness on
your end, decide if they are important or not, and if they can be queued (I
use something similar to what I've read on splitting out A* path finding
algos)

Profile like a pedant.

Implement a queuing system, that as you mentioned, looks at the importance
of certain events, and it may very well be that the guy sitting in town
crafting his 'elvnish boots of waterskiing' will have to wait 5 more seconds
so that the guy underneath 'King Woopass' gets to die again in real time
along with the 3 epic-level clerics suckered into trying to help him.


-brad