Sunday, December 09, 2007

Fungible Reality

One thing I have been saying for at least a decade (in more depth; I'll keep this short) is that technology makes reality fungible. In particular, your reality can be different from my reality.

Of course, we all always bring our own bias, experience, and self to the interpretation of every event; my wife sees Shakespeare very differently than I do. And in the current day, almost everyone spends time looking for information that reinforces their own preexisting world view -- hence the political blogosphere. But, up through the era of the three major television networks, TV was a shared experience: you could talk on Friday about that Thursday evening episode of "Little House on the Prairie".

But, starting more than a decade ago, it became possible for broadcasters to modify your visual experience so that it didn't directly correspond to, for example, the reality that a baseball fan saw at the stadium. It started with "ad inserts" into the background, behind the batter. At first, they were all the same for a given network, but there's no reason at all that they can't be different for different viewers -- and, indeed, I believe that the inserts that Japanese broadcasters put into Major League baseball games are different from what the U.S. broadcasters insert.

Carried to its extreme, almost anybody anywhere in the chain can modify the viewing experience of the end user, on an individual basis. In fact, I think TiVo did this years ago -- selling personal demographic information, or at least promising to show the Cadillac ad to wealthy viewers and the Jeep ad to sportsmen. Thus, TV is no longer a shared experience.

For data carried over IP networks, it's even more trivial. Any web cache or network box can, in theory, modify your personal experience of the web (or any other form of data carried over the Internet, as long as it's not encrypted). And now, via Lauren Weinsein's blog, we find out that Google is no longer a shared experience.

Of course, in one important sense, Google never was; they can (and do, I believe) modify search results to be personally relevant. The difference in this case is that the reality funger is not someone you planned to trust (Google), but someone you didn't (Rogers Telecom).

Twenty-odd years ago, it caused a stir when National Geographic magazine digitally moved one of the pyramids, and the movie "Clue" was considered clever because it had different endings in different theaters. Now, it's within the realm of possibility for someone with enough processing power and the right position in the network to tailor the results of a ball game -- I see the Red Sox win, you see the Yankees win.

What happens when political censors in some authoritarian country get ahold of this technology? Election results, indeed, most of reality, can change. Reality, or at least its perception, has become fungible, "reality-based community" be damned.

Or will Feynman be right in the end?

Friday, December 07, 2007

IP Storage Mailing List Archive

The only link Google could produce (to my queries, anyway) to the IP Storage Mailing List archive was broken. A query to the fine folks at CMU was quickly answered, and you can find the archives here.

My principal impression, some years later, is one of an enormous amount of work: the key players worked very hard to build a high-quality spec. By the time the IPS effort got underway, I was buried in work at the now-nonexistent Network Alchemy. I don't regret any of the time I spent at Alchemy or Nokia (which bought Alchemy), but after having broken some of the initial technical ground, I do wish I could have been more directly involved in the iSCSI effort.

Why am I ruminating about this now? Well, the basic concept of network-attached peripherals, or network-centric system architectures, seems to be percolating back to the surface. It will be interesting to see how it plays out.

Wednesday, December 05, 2007

Netstation "Renewal", and the Genesis of iSCSI

The Netstation web site has moved (click the link). Actually, the page partially moved a while back, but some links broke in the process; it should now be complete.

Netstation was a project at USC's Information Sciences Institute, focusing on the re-architecting of systems around a network instead of a bus. Greg Finn came up with the idea (independently arrived at by others at Cambridge and MIT) in 1991 or earlier, and the project was funded by ARPA 1994-7, if I recall correctly. We did a network-attached display, keyboard, and disk. Arguably, the work that came from Netstation, members of the National Storage Industry Consortium's working group on Network-Attached Storage (notably Garth Gibson, John Wilkes, and Richard Golding), and later work at Quantum Corp. in collaboration with 3com and Adaptec were the genesis of iSCSI.

The idea of network-attached peripherals goes back at least to the early 1980s, and mainframe architectures employ a switched I/O infrastructure that looks like a network if you squint. A number of these are documented in my OSR paper, available from the Netstation page. But I'll take some of the credit for insisting that the protocol be IP-based; see my 1998 ASPLOS paper, "VISA: Netstation's Virtual Internet SCSI Adapter". Simply googling for "iSCSI" doesn't turn up that paper, because it was written before the term "iSCSI" was coined.

When you first bring the idea of IP-attached peripherals up, hardware folks are negative because of the performance implications, but the really difficult problems are security, device discovery, and sharing. The most interesting change is that the boundary of the system disappears. These problems remain research challenges, a decade later, despite a few forays in that general direction, many of them by Garth Gibson and his students, co-workers and collaborators.

(On a side note, one paper that we wrote that was never published was "NXS: X on a Network-Attached Frame Buffer". We submitted it to the 10th X Conference, but it was rejected, and we never revised and resubmitted. I no longer have a copy of the paper; if anyone out there reading it was on the program committee for that conference and is a compulsive pack rat, I'd love to have one back. That was the single hairiest piece of coding I've ever done...)

I should write up a little more on the history and prehistory of iSCSI. The brief timeline on IBM's web page doesn't go into any of that prehistory...