Well i feel small clusters of say 2 computers or so might get more
common in future.
Yet let's start asking:
What is a cluster however?
That's not such a simple answer.
Having a few computers at home connected via a router with simple
default ethernet
is something many have at home.
Is that a cluster?
Maybe.
Let me focus pon the clusters with a decent network.
The decent network clusters suffer from a number of problems.
The biggest problem for this list:
0) yesterday i read in the newspaper another Irani scientist was
killed by a carbomb.
Past few years i really missed experts posting in here and some dorks
who really have nothing to contribute to the cluster world,
and just are there to be here, like Jonathan Aquilina, they get back
in return. So experts leave and idiots come back.
This has completely killed this mailing list.
1) The lack of postings by RGB past few months, especially the ones
where he explains how easy
it is to build a nuke, given the right ingredients, which gives
interesting discussions.
Let's look to clusters:
10) the lack of software support for clusters
This is the real big issue.
Sure you can get expensive commercial software to run on clusters,
but that's all
interesting just for scientists.
Which game can effectively use cluster hardware and is dirt cheap?
This really is a big issue.
Note i intend to contribute myself there to change that, but that's
just 1 person of course.
Not an entire market moving there
11) the huge break even point of using clusterhardware
I can give examples that i sat here at home with next to me Don
Dailey, the programmer of Cilkchess,
which used Cilk from Leierson. We played Diep at a single cpu against
Cilkchess single cpu and Cilkchess
got total toasted.
After having been fried for 4 consecutive games, Don had enough of it
and disconnected the connection
to the cluster, from which he used 1 cpu for the games, and started
to play at a version at his laptop,
which did NOT use CILK. So no parallel framework.
It was factor 40 faster.
Now note that at tournaments they showed up with 500 or even 1800 cpu's,
yet you can't have a cluster of 1800 cpu's at home.
Usually building a 4 socket box is far easier, though not necessarily
cheaper, and practical faster than a small cluster.
Especially AMD has a bunch of cheap 4 socket solutions int he market,
if you buy those 2nd hand ,there is not really
any competition there from 4 socket clusters in the same price range.
100) the huge increase in power consumption lately of machines. Up to
2002 i used to visit
someone, Jan Louwman, who had 36 computres at home, testing
chessprograms at home.
So that wasn't a cluster, just a bunch of machiens, in sets of 2
machines connected with a special
cable we used to play back then machines against each other.
Nearly all of those machines was 60-100 watt or so.
He had divided his computers over 3 rooms or so, majority in 1
room though. There the 16 ampere @ 230 volt
power plug already had problems supplying this amount of
electricity. Around the power plug in the wall,
the wall and plastic of the powerplug were completely black burned.
As there was only a single P4 machine amongst the computers,
only 1 box really consumed a lot of power.
Try to run 36 computers at home nowadays. Most machines are well over
250 watt,
and the fastest 2 machines i've got here eat 410 respectively 270 watt.
That's excluding the videocard in the 410 watt machine, as it's out
of it currently (AMD HD 6970),
the box has been setup for gpgpu.
36 machines eat way way too much power.
This is a very simple practical problem that one shouldn't overlook.
It's not realistic that the average joe sets up at his popular gaming
program a cluster of more
than 2 machines or so.
A 2 machine cluster will never beat a 2 socket machine, except when
each node also has 2 sockets.
So clustering simple home computers together isn't really useful
except if you really cluster together half a dozen or more.
Half a dozen machines, using the 250 watt measure and another 25 watt
for each card and 200 watt for the switch,
it's gonna eat 6 * 275 + 200 = 1850 watt. You really need diehards
for that.
They are there and more than you and i guess, but they need SOFTWARE
that interests them that can use it in a very
efficient manner, clearly proven to them to be working great and
easy to install, which refers to point 11.
101) most people like to buy new stuff. new cluster hardware is very
expensive for more than 2 computers as it needs a switch.
Second hand it's a lot cheaper, sometimes even dirt cheap,
yet that's already not what most people like to do
110) Linux had a few setbacks and got less attractive. Say when we
had redhat end 90s with x-windows it was slowly improving
a lot. Then x64 was there together with a big dang and we went
back years and years to x.org.
X.org threw back linux 10 years in time. It eats massive RAM,
it's ugly bad, it's slow, it's difficult to configure etc.
Basically there isn't many good distributions now that are for
free.
As most clusters work only very well under linux, the
difficulty of using linux should really be factored in.
Have a problem under linux?
Then forget it as a normal user.
Now for me linux got MORE attractive as i get hacked total
silly by every consultant who on this planet knows how to hack on the
internet,
yet that's not representative for those with cash who can
afford a cluster. Note i don't fall into the cash group. My total
income in 2011 was real little.
111) Usually the big cash to afford a cluster is for people with a
good job or a tad older, that's usually a different group than the
group that
can work with linux. See the previous points for that
Despite all that i believe clusters will get more popular in future,
for a simple reason: processors don't really clock higher.
So all software that can use additional calculation power already is
getting parallellized or already has been paralelllized.
It's a matter of time before some of those applications also will
work well at cluster hardware. Yet this is a slow proces
and it really requires software that works real efficient at small
number of nodes.
As an example of why i feel this will happen i give to you the
popularity amongst gamers to run 2 graphics cards connected via a
bridge with
each other within 1 machine.
Yet the important factor there is that the games really profit from
doing that.
Post by Lux, Jim (337C)Post by Ellis H. Wilson IIII
recently read a blog that suggested (due to similar threads following
these trajectories) that the Wulf list wasn't what it used to be.
I think that's for a variety of reasons..
The cluster world has changed. Back 15-20 years ago, clusters were new,
novel, and pretty much roll your own, so there was a lot of traffic on the
list about how to do that. Remember all the mobo comparisons, and all the
carefully teased out idiosyncracies of various switches and network
schemes.
Back then, the idea of using a cluster for "big computing" was kind of
new, as well. People building clusters were doing it either
because the
architecture was interesting OR because they had a computing
problem to
solve, and a cluster was a cheap way to do it, especially with free labor.
I think clustering has evolved, and the concept of a cluster is totally
mature. You can buy a cluster essentially off the shelf, from a whole
variety of companies (some with people who were participating in this list
back then and still today), and it's interesting how the basic Beowulf
concept has evolved.
Back in late 90s, it was still largely "commodity computers, commodity
interconnects" where the focus was on using "business class"
computers and
networking hardware. Perhaps not consumer, as cheap as possible, but
certainly not fancy, schmancy rack mounted 1U servers.. The switches
people were using were just ordinary network switches, the same as in the
wiring closet down the hall.
Over time, though, there has developed a whole industry of supplying
components specifically aimed at clusters: high speed interconnects,
computers, etc. Some of this just follows the IT industry in
general..
There weren't as many "server farms" back in 1995 as there are now.
Maybe it's because the field has matured?
So, we're back to talking about "roll-your-own" clusters of one sort or
another. I think anyone serious about big cluster computing (>100 nodes)
probably won'd be hanging on this list looking for hints on how to route
and label their network cables. There's too many other places to go get
that information, or, better yet, places to hire someone who
already knows.
I know that if I needed massive computational power at work, my first
thought these days isn't "hey, lets build a cluster", it's "let's call up
the HPC folks and get an account on one of the existing clusters".
But I still see the need to bring people into the cluster world in some
way. I don't know where the cluster vendors find their people, or even
what sorts of skill sets they're looking for. Are they beating the bushes
at CMU, MIT, and other hotbeds of CS looking for prior cluster design
experience? I suspect not, just like most of the people JPL hires don't
have spacecraft experience in school, or anywhere. You look for bright
people who might be interested in what you're doing, and they learn the
details of cluster-wrangling on the job.
For myself, I like probing the edges of what you can do with a
cluster.
Big computational problems don't excite me. I like thinking about things
1) What can I use from the body of cluster knowledge to do something
different. A distributed cluster is topologically similar to one all
contained in a single rack, but it's different. How is it different
(latency, error rate)? Can I use analysis (particularly from early cluster
days) to do a better job.
2) I've always been a fan of *personal* computing (probably from many
years of negotiating for a piece of some shared resource). It's tricky
here, because as soon as you have a decent 8 or 16 node cluster that fits
under a desk, and have figured out all the hideous complexity of how to
port some single user application to run on it, someone comes out with a
single processor box that's just as fast, and a lot easier to use.
Back
in the 80s, I designed, but did not build, a 80286 clone using
discrete
ECL logic, the idea being to make a 100MHz IBM PC-AT that would run
standard spreadsheet software 20 times faster (a big deal when your huge
spreadsheet takes hours to recalculate). However, Moore's law and Intel
made that idea a losing proposition.
But still, the idea of personal control over my computing resources is
appealing. Nobody watching to see "are you effectively using those cpu
cycles". No arguing about annual re-adjustment of chargeback rates where
you take the total system budget and divide it by CPU seconds.
Ooops not
enough people used it, so your CPU costs just quadrupled.
3) I'm also interested in portable computing (Yes, I have a NEC 8201-
TRS-80 Model 100 clone, and a TI-59, I did sell the Compaq, but I had one
of those too, etc.) This is another interesting problem space.. No big
computer room with infrastructure. Here, the fascinating trade is between
local computer horsepower and cheap long distance datacomm. At some
point, it's cheaper/easier to send your data via satellite link to a big
computer elsewhere and get the results back. It's the classic 60s remote
computing problem revisited once again.
_______________________________________________
Computing
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