[Beowulf] Cluster for Finite Element Analysis

[Jeffrey B. Layton]

Srini,

   There are some FEX experts on this list and we'll see if
they jump in to help (probably to correct my mistakes :)  ).
I'll put some answers in-line below.

>Hi,
>
>I am beginner and just started to learn about cluster technology. My goal is
>to build a cluster that could be used for FEA ultimately.  I have searched
>the web and it confused me more on how to do this. I was advised that this
>was a good place to ask questions and I would be getting some real help.
>
>1. Did anybody built a cluster for FEA application?
>  
>

   Sure. Lots of people run FEA on clusters. Do you plan to use
a commercial FEA package or do you want to write your own?
   If it's a commercial package then you will likely need lots of
IO for each node. A few disks configured using RAID-0 (striping)
to get maximum bandwidth.
   If you're writing your own, well then you are in luck. If you
design your code well, you IO requirements should be small
(one of the reasons commercial packages use so much IO is due
to using legacy code that is not really designed for distributed
memory). Anyway, the biggest thing you have to worry about
from a cluster perspective is the solver. There are a number of
good parallel sparse solvers out there. Some of them are even
good at out-of-core solutions. There are also some good dense
solvers out there (PLAPACK is my recommendation) that
also have out-of-core capability.

>2. What type of cluster should I select for FEA ?
>  
>
   If you are using either a commercial package or writing your
own, network bandwidth it likely to be a bottleneck. So something
like Myrinet, IB, Quadrics, Dolphin, etc. are good choices. If
these are too expensive, then GigE is the way to go.
   For commerical apps, you're going to need lots of IO in
the nodes.

>3. What Clustering software and other software packages should I be
>considering?
>  
>
   My recommendation is Warewulf (warewulf.lbl.gov/pmwiki/).
It has a lot of great features that clusters should have. I can go
into details if you like, but if you look in the beowulf archives
you'll see some postings about Warewulf.

>4. What are my minimum hardware requirements?
>  
>

  This depends. How big are your problems? How much memory
do they take?
   You can even run a parallel code on a single node (not efficient,
but reasonable for experimentation).
   I would rank your priorities in the following order:

1. network bandwidth
2. IO bandwidth (for commercial codes)
3. Amount of memory
4. Processor speed
5. Cluster management system

>5. Is there a set procedure on how I could proceed in building this cluster?
>  
>

   Doug Eadline and I are writing a magazine article series on how to
build a small cluster for $2500. The series is in ClusterWorld Magazine
and you can find some of what we discuss at the following URL:
http://www.clusterworld.com/value_cluster.shtml
For $2500 we have 8 nodes with AMD Sempron 2500+ CPUs, 256 MB
memory in each node and a GigE network. This was the price at the
end of last year. Recently I repriced everything and the price is just
a bit over $2000.
   This cluster just set a record for GFLOPS per dollar:
http://www.clusterworld.com/value_cluster.shtml#gflops

Good Luck and have fun!

Jeff