[computer-go] Pay-as-you-go cluster?

[Darren Cook]

>> *:asynchronously: once all leaf nodes have replied the minimax tree is
>> made.
> 
> Using a cluster is only going to work reliably if you design for the
> possibility that a node will never reply. One way to do that is assign
> nodes that finished already to the same task(s) of nodes that didn't
> reply yet.

Good point. UCT (if I understood correctly) has at any time a best
answer, so it could send that back every second. And if a CPU has not
sent anything in the last two seconds it could be assumed to be dead and
another CPU assigned to the task. Or just use the last answer it sent if
it was close to finishing.

Also you could use alpha-beta instead of minimax and once enough CPUs
have replied you can prune some nodes: you could send a cancel signal to
those CPUs and reassign them to a more useful part of the tree.

I bet there are chess papers on all of this :-).

Darren