[Beowulf] cloud: ho hum?
hahn at mcmaster.ca
Wed Feb 1 07:08:24 PST 2012
in hopes of leaving the moderation discussion behind,
here's a more interesting topic: cloud wrt beowulf/hpc.
when I meet cloud-enthused people, normally I just explain how
HPC clustering has been doing PaaS cloud all along. there are some
people who run with it though: bioinformatics people mostly, who
take personal affront to the concept of their jobs being queued.
(they don't seem to understand that queueing is a function of how
efficiently utilized a cluster is, and since a cloud is indeed a
cluster, you get queueing in a cloud as well.)
part of the issue here seems to be that people buy into a couple
fallacies that they apply to cloud:
- private sector is inherently more efficient. this is a bit
of a mystery to me, but I guess this is one of the great rhetorical
successes of the neocon movement. I've looked at Amazon prices,
and they are remarkably high - depending on purchasing model,
about 20x higher than an academic-run research cluster. why is there
not more skepticism of outsourcing, since it always means your cost
includes one or more corporate profit margins?
- economies of scale: people seem to think that a datacenter at the
scale of google/amazon/facebook is going to be dramatically cheaper.
while I'm sure they get a good deal from their suppliers, I also
doubt it's game-changing. power, for instance, is a relatively
modest portion of costs, ~10% per year of a server's purchase price.
machineroom cost is pretty linear with number of nodes (power);
people overhead is very small (say, > 1000 servers per fte.)
most of all, I just don't see how cloud changes the HPC picture at all.
HPC is already based on shared resources handling burstiness of demand -
if anything, cloud is simply slower. certainly I can't submit a job to
EC2 that uses half the Virgina zone and expect it to run immediately.
it's not clear to me whether cloud-pushers are getting real traction with
the funding agencies (gov is neocon here in Canada.) it worries me that
cloud might be framed as "better computing than HPC".
I'm curious: what kind of cloudiness are you seeing?
thanks, mark hahn.
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