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Optical Fiber Storage
TypeCast writes "When you've got Canada's elbow room, perhaps you can squeeze in a 'disk drive' 5,000 miles in diameter. But the plan by Canada's CANARIE researchers for a Wavelength Disk Drive (WDD) within optical networks suggests all of Universal Music's library would still make for a tight squeeze as light-speed storage. Here's a white paper on the WDD for those who aren't afraid of MS Word documents."
Our friendly geek is once again in a state court...
[judge] So does your controversial web page reside in California?
[geek] It resides in California 15 milliseconds every 350 milliseconds, your honor.
[judge] Pardon me?
[geek] My web page is served on optical fiber storage. It goes around the country in a big circle.
[judge] B-but it's stored somewhere in California, r-right?
[geek] No sir, it's encoded in photons travelling at the speed of light, you honor.
[judge] [thinking for a few seconds] Goodness, I'd rather be put on a simple divorce case.
The concept is absolutely not new. Every FDDI ring topology could be used for/with this. Whereas Token ring only allows one single packet to circulate within the ring, this "new" concept allows, no, requires the ring to be filled up.
The "new" idea was not the ring as network topology nor the storage itself (has been done acoustically as stated above), but to coordinate client-server clusters with this. But clusters organized in ring-topology are not new either.
In the proposed topology the master server just injects "to-be-done" packets into the ring. The clients pick up (and remove) one packet from the ring each time they want to start crunching the next work packet. The other packets will be circulating the ring until solved.
Main problem is that one will be either wasting a lot of transmission capacity for idle data circulation - or be running into capacity problems. There is a reason why most detail work when designing clusters goes into designing the optimum network architecture for the specific problem...
I remember seeing an article about nano-motors that used vaporised water to move a piston that made a shaft rotate. A friend pointed out it was a steam engine. Just very small.
Now people are talking about fibre optic delay lines as storage devices. Some of the earliest computers stored data as sound waves in mercury and
nickel wires. A speaker injected sound in one end, it was picked up my a microphone at the other, re-shaped and squirted back in.
Same idea, different medium.
And here is the HTML version kindly genereated by freviewer.
Be careful. People in masks cannot be trusted.
SETI@home works in client-server fashion: your desktop computer asks the main server for a chunk of data, then chews on the data and talks to the server again. This is massively parallel computation, but it isn't peer-to-peer, it's client/server.
When you put data on this fiber ring, within a very short time all the computers on the ring have seen the data. So if you want a bunch of computers to cooperate on a job, this would be a great way for them to update each other on what they are doing. If you did it right, you would have massively parallel distributed processing: all the computers in Canada tied into a single InterComputer. And just as Napster can spread popular songs around where a single FTP server would be hammered, an InterComputer potentially could handle truly large computations that any single computer (or even Beowulf cluster) couldn't.
Multicast data packets aren't new; that's why they said it takes only a few changes to try out their ideas. Multicast packets are currently designed to die fairly quickly so they can't clog a network up too much; these guys want the packets to go all the way around the ring.
P.S. That joke about the backhoe chopping the fiber was only a little bit funny, and then only the first time. When a backhoe hits a cable today, half of Canada does not lose Internet service! It isn't a trivial ring; it has some redundancy redundancy.
steveha
lf(1): it's like ls(1) but sorts filenames by extension, tersely
You can download it here:
Cheers,Wavedisk White Paper (PDF)
Chase
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that the data access time is comparable to RAM.
So shared data between processes executing in multiple computers from vancouver to halifax can be quickly accessed and updated.
The speed increase over requesting the data from ether over it being in some computer's cache depends on how fast that computer's connection is to a backbone's router.
Although now that I do some quick calcs, the max latency turns out to be, 180000(k/s)/8000(km) = 1/23rd of a second = 45ms, and avg latency 22ms, which is slower than HD.
You'd be saving 5ms to 10ms maybe over getting the data from a cpu behind a router, so the applications are indeed pretty narrow, but not non-existant.