1. Peer-to-Peer Information Systems Week 14: Distributed Computing
Old Dominion University
Department of Computer Science
CS 495/595 Fall 2003
Michael L. Nelson
11/24/03

2. Grid Computing Compute Grids… Data Grids… Access Grids… etc.
what do they mean?
An early definition:
“A computational grid is a hardware and software infrastructure that provides dependable, consistent, pervasive, and inexpensive access to high-end computational capabilities”
Foster & Kesselman, The Grid: Blueprint for a New Computing Infrastructure, 1998

3. An Updated Definition
“…coordinated resource sharing and problem solving in dynamic, multi-institutional virtual organizations…”
“The sharing that we are concerned with is not primarily file exchange but rather direct access to computers, software, data, and other resources…”
Foster, Kesselman & Tuecke, “The Anatomy of the Grid: Enabling Scalable Virtual Organizations”, International J. Supercomputer Applications, 15(3), 2001
(emphasis is mine - MLN)

4. The Grid for Virtual Organizations
from: Foster, Kesselman & Tuecke, “The Anatomy of the Grid: Enabling Scalable Virtual Organizations”,
International J. Supercomputer Applications, 15(3),

5. Grid Checklist
Coordinates resources that are not subject to centralized control…
(crosses domains of control/administration)
…using standard, open, general-purpose protocols and interfaces…
(general purpose, non-application specific APIs, services)
…to deliver nontrivial qualities of service
(complex and dynamic QoS; whole greater than sum of parts)
from: Foster, “What is the Grid? A Three Point Checklist”, GRIDtoday, 1(6), 2002.

6. Grid Misconceptions The Grid… is a next-generation Internet
it builds on top of the Internet
is a source of free cycles
controlled sharing
requires a distributed operating system
TCP/IP model, not a virtual machine model
requires new programming models
proper abstraction and encapsulation should preserve current models
makes high-performance computers superfluous
low latency, high bandwidth problems not yet suitable for the Grid
from: Foster, Kesselman & Tuecke, “The Anatomy of the Grid: Enabling Scalable Virtual Organizations”,
International J. Supercomputer Applications, 15(3),

7. Grids and P2P
In practice, we find that the technical focus of work in these domains has not overlapped
significantly to date. One reason is that peer-to-peer and Internet computing developers have so
far focused entirely on vertically integrated (“stovepipe”) solutions, rather than seeking to define
common protocols that would allow for shared infrastructure and interoperability. …
Another is that the forms of sharing targeted by various applications are quite limited,
for example, file sharing with no access control, and computational sharing with a
centralized server.
As these applications become more sophisticated and the need for interoperability becomes
clearer we will see a strong convergence of interests between peer-to-peer, Internet, and Grid
computing.
(emphasis is mine - MLN)
from: Foster, Kesselman & Tuecke, “The Anatomy of the Grid: Enabling Scalable Virtual Organizations”,
International J. Supercomputer Applications, 15(3),

8. P2P Computation Projects - Proto Grid?
cryptography, math puzzles
distributed chess playing
drug, protein research
many others at:

10. SETI Located in Arecibo, Puerto Rico SETI@Home
SERENDIP antenna is a secondary antenna
processed signals w/o storing; uses a dedicated super-computer
focused on the hydrogen line (1.42 GHz)
SERENDIP analyzes a 140 MHz band
snail mail digital tapes back to Berkeley for processing
analyzes a 2.5 MHz band, but does better analysis
pictures from:

11. SETI@home Work Units Data sizes are chosen to be ~ 300Kb
big enough to occupy your computer for a while, but small enough not to impose too much of a bandwidth load
Data splitting is a computationally intensive task
a cluster of workstations are dedicated to this task
A Napster-style work dispatcher delegates work and receives results
statistics pages are updated in batch mode

12. SETI@home Architecture
from:
from:

13. Aggregate TFLOPS (ca. 2001) ASCI White SETI@home 12.3 TFLOPS peak
12.3 TFLOPS peak
$110M
106 Tons
~ $700k for 1 year of operation
(not counting existing PCs)
1 day ~ 700k work units ~ 20 TFLOPS

14. Will Grids Have the Same Impact as P2P?
``Grid Computing is, according to the Grid Information Centre a way to
"...enable the sharing, selection, and aggregation of a wide variety
of geographically distributed computational resources." It is, in
other words, an attempt to make Sun's famous pronouncement "The
Network Is The Computer" an even more workable proposition. (It is
also an instantiation of several of the patterns of decentralization
that used to travel together under the name peer-to-peer.)
IBM defines it more narrowly: Grid Computing is "... applying
resources from many computers in a network-at the same time-to a
single problem" , and the MIT Technology Review equated Grid
technology with supercomputing on tap when it named Grids one of
"Ten Technologies That Will Change the World.”’’
from:
(emphasis is mine - MLN)

15. Grids For The Masses?
`` This view is wrong. Supercomputing on tap won't live up to to this
change-the-world billing, because computation isn't a terribly
important part of what people do with computers. This is a lesson we
learned with PCs, and it looks like we will be relearning it with
Grids.’’
from:

16. coolness(“grid”) >> coolness(“distributed batch processing”)
Shirky asserts that the “grid” is really just distributed batch processing (again)
, web, games are primary reasons for selling PCs
not calculation, spreadsheets, etc.
General users are interested in peak performance to support their primary tasks (e.g., 3D graphics in games or movie editing)
most users don’t have problems suitable for distributed batch processing
“Of all the patterns supported by decentralization, from file-sharing to real-time collaboration to supercomputing, supercomputing is the least general.”

17. The Killer App for PCs? What if the killer applications for PCs are:
file sharing
game playing
chatting
video conferencing
Its not that the grid won’t be useful, its just likely to be limited to a secondary impact for most users…
however, distributed batch processing projects will be able to capitalize on the increasing number of powerful PCs purchased for their peak performance

18. Tapping Into the Sociology…