Tuesday, September 23, 2003

O'Reilly Network: Distributed Computing Economics and the Semantic Web [Jim Gray ppt]

O'Reilly Network: Distributed Computing Economics and the Semantic Web [Sep. 22, 2003] "I went to see Jim Gray speak the other night. He was the first speaker in this fall's Distinguished Speaker series at SDForum. I liked the talk a lot. In particular, I very much enjoyed the part of his talk dealing with Distributed Computing Economics.
The argument itself is basic economic analysis, and can be boiled down to the notion that since everything costs money, you should consider the costs of everything when building applications. In particular, Gray focuses on the costs of cpu time (small, and dropping all the time) and the cost of network bandwidth (not so small, and decreasing at a slower rate). By putting actual dollar values on things, Gray is able to draw some startling conclusions about when it makes sense to use grid-computing techniques, and when it makes sense to either use a LAN-based system or a single machine (as opposed to distributing the computation over a WAN, or using "on-demand" computing).
In particular, he says the following: the break-even point is 10,000 instructions per byte of network traffic, or about a minute of computation per MB of network traffic. That is, unless the cpu time at the other end of the pipe is free, and you get a minute of computation for every MB of data you send to it, you're better off doing the computation locally.
Now along comes Gray, making an argument that, when you think about it, implies that the semantic web, as currently conceived, might just be all wrong. His basic point is that it's far cheaper to vend high-level apis than give access to the data (because the cost of shipping large amounts of data around is prohibitive). Since the semantic web is basically a data web, one wonders: why doesn't Gray's argument apply?"

(Jim Gray's ppt)
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