Computer Science research done on Beowulf class systems

[Walter B. Ligon III]

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> > A few really
> > large sites might need to spread the load a bit, but would probably be better
> > served my multiple servers that work together than a beowulf.
> 
> Obviously we are back to "What's a beowulf?" Multiple servers that
> work together is a traditional cluster. Businesses, btw, have used
> clusters for as long as scientific programmers have used clusters. The
> wall street firm I used to work for didn't have any machine with more
> than 2 CPUs, nor did they do any parallel programing, but they had a
> large cluster. They built it for availability and throughput reasons.

Yeah, well, I really don't want to debate that.  What you have said here is
exactly my point.  Beowulf isn't really the approach for these problems, but
there are other good approaches.  "Clusters" have been around for a long time
in many different forms, and certainly they are a technique for improving
throughput and capacity.  Beowulf is a parallel computer architecture.  Most
of the resources in a beowulf are for internal use.  A lot of what I said
in that posting was actually generic to parallel computers - which HAVE
been around longer than computers clustered for business use.

Anyway, people tend to think that parallel systems are going to magically
fix anything and that's not the case.  I think it is important they know
that and why.  For an extreme example there was a professor where I went
to school that worked in AI (quite a good one, too) who told a class that
the implementation complexity of some search algorithm didn't matter because
soon parallel computers would be able to run them very quickly.  The algorithm
was NP-complete.  Parallel computers AREN'T going to fix that.

> > A beowulf really doesn't have facilities to support really really
> > large external network traffic.
> 
> But my cluster does. And, actually, even the strict definition of
> "beowulf" doesn't outlaw big gateways.

Well, I didn't really mean that you can't put a big ol' NIC in your
beowulf.  I mean that all of the network bandwidth and CPU power isn't
easily adapted to a problem without a fairly large ratio of computation
and local I/O to data being shipped into or out of the site.
To re-iterate what you have said, there ARE other clustering
approaches that DO provide this.

> So watch out for folks who use "beowulf" interchangably with "cluster".
> I don't, but most of the new people asking questions on this mailing
> list do.

Well, I feel I should work to educate them, not support their misconceptions.

Walt

-- 
Dr. Walter B. Ligon III
Associate Professor
ECE Department
Clemson University