Eliezer S. Yudkowsky wrote:
>
> If you need an OS to do something, rewrite Linux.
> And hasn't Beowolf done distributed supercomputing already?
>
Actually, Beowulf is a set of Linux extensions that permit
disributed supercomputing of the traditional kind in which
the applicatons are specifically written to use the beowulf
infrastructure. It's very impressive in the traditional
supercomputing domain. There is another linux extension effort
that I find more interesting: Mosix. The Mosix extensions
allow a cluster to loadshare at the task level, without the
applications needing to know about the infrastructure. If all
the computers on the internet were running Mosix, in theory
any time a task was spawned or suspended anywhere, it could
migrate anywhere else to execute. In practice, task migration
decision algorithms are "non-trivial", so such a large Mosix would
certainly fail as the coordination bandwidth usage exceeds the
effective gain in CPU utilization. However, these algorithma
are amenable to optimization. The exciting current work is for
large locally-connected clusters, so less is being done for
internet-connected migration algorithms. We know that some
distributed algorithms work well even with very poor connectivity:
look at the Mersenne prime or DES cracking efforts. At the other
end of the scale, Some tasks have such a high intertask bandwidth
that it is essentially infeasible to run them in separate menories.