First 500 Terabytes Transmitted via LHCGlobal Grid

neutron_p writes "When the LHC Computer Grid starts operating in 2007, it will be the most data-intensive physics instrument on the planet. Today eight major computing centers successfully completed a challenge to sustain a continuous data flow of 600 megabytes per second on average for 10 days from CERN in Geneva, Switzerland to seven sites in Europe and the US. The total amount of data transmitted during this challenge -- 500 terabytes -- would take about 250 years to download using a typical 512 kilobit per second household broadband connection."

Comments

But will....

[cyngus]

...this network be able to handle Longhorn SP1?

That's all nice, but

[KinkifyTheNation]

Can it handle a slashdotting?

Great!

[Evanisincontrol]

Now we don't have to wait around for our porn!

Re:Great!

[dlZ]

Now we don't have to wait around for our porn!

Only on /. is this insightful and not funny!

This pales in comparison to...

[prisoner-of-enigma]

...a box full of DLT, LTO, or AIT tapes. With FedEx at my side, I can have several hundred terabytes sent almost anywhere on the planet in 24 hours.

Of course, the latency for this gargantuan data pipeline is a bit on the high side...

Re:This pales in comparison to...

[dave-tx]

I'm playing Quake III via FedEx, but the prices are killing me.

Re:This pales in comparison to...

[ricky-road-flats]

I'm playing Quake III via FedEx, but the prices are killing me.

Me too, but it's the frame rates that are killing me (and getting me killed).

Re:This pales in comparison to...

[prisoner-of-enigma]

You do realize it was a joke, don't you?

But to address your point, yes, tape can be slow. However, the best tape drive money can buy right now (a title claimed by HP's Ultrium 960) is faster than most hard drives -- 160MB/sec according to the specs. It's not going to be that bad. Expensive, yes, but not slow.

Just a thought experiment: sending a terabyte of data via this tape solution would require (1,000,000 megs / 160 megs per sec) 6,250 seconds, or 104 minutes to write to tape. This assumes 2:1 compression of course, but the actual compressability is unknown.

Sending 500 terabytes in this fashion would require 866 hours (36 days) to write and that same amount to read back onto disk. 72 days sounds like a lot, but this could be shrunk down to as little as 104 minutes if you're willing to employ 500 simultaneously-operating Ultrium 960 tape drives. Expensive, yes, but this is a fun thought experiment where dollars don't matter. Let's assume you use ten drives in an array on both ends (ship the drives with the media to save buying double drives), shrinking your backup/restore times to 86.6 hours (3.6 days) each.

7.2 days plus FedEx Priority Overnight transit time of about 16 hours yields a total transfer time of 7.87 days (7 days, 20 hours, 52 minutes, 48 seconds), or about 680,400 seconds to transfer 500,000,000 megabytes. This gives us a sustained transfer rate of 734MB/sec. This is 22% better performance than the link in the article. The time could be shrunk to as little as one day (the vast majority of it FedEx transit time) if you have 500 tape drives operating all at once.

Total expenditure for such an enterprise would be 10 Ultrium 960 drives (10x$6,190 each = $61,900) and 625 tape cartridges (625x$129 each = $80,625), for a total hardware cost of $142,525. FedEx International Priority shipping costs for a box of tapes like this would be $603, bringing the grand total to $143,128.

Just for giggles, a 500-drive array would cost you $3,095,000 in drive hardware but still take only $80,625 in tapes. With shipping it's a mere $3,176,228.

I'm willing to bet the LHC network costs considerably more than that to operate. What's more, the "tape" network hardware costs need be borne only once. The only operating costs are FedEx shipping costs and replacement tapes if and when needed. It's actually a very efficient way to send huge sums of data from place to place when you think about it.

Note: I've done all this math off the cuff while doing about ten other things, so if my figures are off, don't try to have me drawn and quartered. It was a joke, and it's supposed to be mildly entertaining.

Dark Fibre

[superpulpsicle]

At least things can transfer alot faster within US, if we actually lit the dark fibre underground. We planted so many during the .com eras, yet so many are still unlit due to unwillingness to the hire more techies for maintainance.

Well going outside the US is a different story. I really don't know how we connect to Europe etc.

Re:Dark Fibre

[jeffmeden]

Huh? The cost of laying the fiber pales, as you partly mentioned, when compared to the cost of fiber transceiving equipment. There are tons of 'dark' copper lines as well, that could sustain much greater data throughput than they currently do, but its all about how the data is handled at either end. The same goes for intercontinental runs. You think they are dropping cables one at a time? There is enough bundled up capacity for a long time, but it's 'dark' until it's cost effective to put the gear at either end to use it.

42

[ARRRLovin]

And then they shut the thing down.

Cost

[aerozeppl]

Thats great and all but none of us will be on anything like that for years. If Time Warner had that here they would charge one child a month. You would need 12 wives just to cover your internet bill.

Re:Cost

[precize]

I know this makes me a horrible person, but technically, you would only need 9 wives...

At last!

[ArAgost]

The perfect solution to connect my beowulf clusters!

Where is the torrent ?

[4nd3r5]

Ive been looking all over for it.

RIAA

[rdurell]

Only 10 days? I guess the RIAA sent cease and desist letters.

Re:rr

[slavemowgli]

You'd be surprised at the amounts of data captured during experiments in high-energy physics - and keep in mind that this was 500 TB in a *week*, which is longer than you usually want to wait for your data transfer to complete.

640 MB/sec

[scovetta]

"640K ought to be enough for anybody." --Bill Gates, 1981

"640MB/sec ought to be enough for anybody." --Me, /., 2005

Standard terms

[Quixote]

What is with these non-standard terms like "Terabytes" and "Megabytes"? Please re-state the bandwidth and the amount of data tranferred in LoCs (Libraries of Congress) and KLoCs (Kilo Libraries of Congress) so that the rest of the world can understand the magnitude of this achievement.

Not sure why this is completely notable

[rnxrx]

600 MB/sec = 4.8 Gb/sec.

OK... they lit up the equivalent of two OC48's worth of bandwidth. That's half of an OC192 or a 10G Ethernet. There have been long haul OC192's for a number of years now. If I hook up a hardware-based traffic generator and run at 100% over an OC192 for a few weeks will I get a slashdot article, too?

Re:Not sure why this is completely notable

[stefanb]

OK... they lit up the equivalent of two OC48's worth of bandwidth. That's half of an OC192 or a 10G Ethernet. There have been long haul OC192's for a number of years now. If I hook up a hardware-based traffic generator and run at 100% over an OC192 for a few weeks will I get a slashdot article, too?

The accomplishment is not in the data rate, it's in the ability of the participating organisation's to get a stable network going. One that is close enough to the one that the real scientists will be using in a couple of years.

Consider that there's a large number of institutes, universities, etc. that all have their own IT departments, plus all the physicists that have to be involved because it's their grant money funding all this. It's thousands of people coordinating. And I would be surprised if they hadn't set up different service classes, priorisation schemes and what not.

Setting up a trivial network between a couple of sites that are all under your control is close to trivial: you just need to talk to you telco and buy the lines, and hook up the routers. But establishing a working network between these many institutions takes a lot more.

MPAA & RIAA

[killtherat]

On a related note, CERN is now being sued by the MPAA & RIAA. A spokesmen was commented, saying, "Obviously with 500 terabytes of data being transmitted on the internet, at least some of it had to be copyrighted materials represented by the RIAA and the MPAA. As we know, the internet and communication grids serve no real purpose other then to pirate movies and music."
The lawsuit is expected to destroy CERN and any sort of decent networking research anybody was even thinking about doing for the next 50 year.

Re:rr

[morcheeba]

Keep in mind that was 500 TB in a *metric week* -- 10 days. Those crazy physicists!

Somewhere on Naboo..

[Sri Ramkrishna]

Seth Lord and RIAA Chief Mitch Bainwol, felt a sudden disturbance in the force. It was a like a thousand music producers and label execs suddenly cried out in grief and dispair.

sri