[nycbug-talk] Parallel Virtual Machine

[George Georgalis]

On Wed, Apr 12, 2006 at 11:23:33AM -0400, Pete Wright wrote:
>On Tue, Apr 11, 2006 at 11:17:05PM -0400, George Georgalis wrote:
>> On Tue, Apr 11, 2006 at 08:57:59AM -0700, Peter Wright wrote:
>> >
>> >> Hey All,
>> >>
>> >> A colleague of mine just found something called PVM, which looks like
>> >> a really interesting problem-solver (cheap and easy distributed CPU
>> >> use?):
>> >
>> >yea i remember checking it out a while back.  it seemed pretty good if you
>> >are writing a custom application.  if i remember correctly PVM provides C
>> >lib's that allow you to pass messages via network sockets to your cluster
>> >for computation.  unfortunatly, i was never in a situation where i could
>> >use it.
>> 
>> I think it was shipped in the redhat desktop since 6.0 or 6.1.
>> But I've never seen it running. Think pov-ray mentioned it before,
>> but now there's http://www.instant-grid.org/ or Sun Grid Engine 
>> and others...
>> 
>
>heh...RH ships the pvm libs?  i didn't realize that, must have missed it
>inbetween the kitchen sink and bathtub they also supply :)  I think
>this architecture is different than a "grid" or what ever market-speak
>is being used today.  from what i've gathered, grid's are mainly batch
>processing systems that do some tricks to spread the load amoung a farm
>of cpu's.  a PVM seemed closer to a large shared memory cluster.  it may
>seem like a trivial difference but from a programming and application
>perspective it's pretty huge.  from what I understand, a grid/batch
>system will take a discreet chunk of code - process it - then send the
>result back to the master.  a shared memory cluster is able to take one
>set of instructions and have the computation spread along multiple
>machines at the same time.


Pretty much right on. SGE (et al) works if you can break the work
into a batch set, while PVM is better if your threads need shared
memory. If you like both apples and oranges, an grid is a lot
easier to execute than PVM,

And thanks to Patrick for the really experienced perspective.

But hold on, before going out PVM developing. The Sun Fire T2000

 # UltraSPARC T1 processor with CoolThreads technology offers up
 to eight 4-way multithreaded cores.
 # Typical processor power consumption of 72 watts, delivering 32
 simultaneous threads.

it's 2-u, green and starts at under $8000. If you are running
a threaded app like apache; you may need to buy a lot of extra
equipment to load test it.

// George


-- 
George Georgalis, systems architect, administrator <IXOYE><
http://galis.org/ cell:646-331-2027 mailto:george at galis.org