20-755: The Internet
Lecture 1: Introduction
David O’Hallaron
School of Computer Science and
Department of Electrical and Computer Engineering
Carnegie Mellon University
Institute for eCommerce, Summer 1999
Lecture 01, 20-755: The Internet, Summer 1999
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Today’s lecture
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Course overview (25 min)
Internet history (25 min)
break (10 min)
Research overview (50 min)
Lecture 01, 20-755: The Internet, Summer 1999
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Course Goals
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Understand the basic Internet infrastructure
– review of basic computer system and internetworking
concepts, TCP/IP protocol suite.
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Understand how this infrastructure is used to
provide Internet services
– client-server programming model
– existing Internet services
– building secure, scalable, and highly available services
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Understand how to write Internet programs
– Use DNS and HTTP to map a part of the CMU Internet
– Build a server that provides an interesting Internet
service.
Lecture 01, 20-755: The Internet, Summer 1999
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Teaching approach
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Approach the Internet from a host-centric
viewpoint
– How the Internet is used to provide services.
– Complements the network-centric viewpoint of 20-770:
Communications and Networking.
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Students learn best by doing
– In our case, this means programming.
Lecture 01, 20-755: The Internet, Summer 1999
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Course organization
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14 lectures
– Readings from the textbook and supplementary readings
are posted beforehand.
– Guest lecture: Bruce Maggs, SCS Assoc Prof and VP for
Research at Akamai, a Boston-based Internet startup.
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Evaluation
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Class participation (10%)
Two programming homeworks (20%) (groups of up to 2)
Programming project (50%) (groups of up to 2)
Final exam (20%)
Office Hours
– Mon 2:00-3:30
– These are nominal times. Visit anytime my door is open.
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Programming assignments
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Will be done on euro.ecom.cmu.edu
– Pentium-class PC server running Linux
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Homeworks will use Perl5.
Project can use language of your choice.
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Question:
– Does the class need additional tutoring in editing and
running Perl5 programs on a Unix box?
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Scheduling issues
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We’ll need to double up on lectures (10:3012:20 and 1:30-3:20) on three different days:
– Mon July 12
– Fri July 16
– Fri July 23
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No class Fri Aug 6.
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Course coverage
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Intro to computer systems (2 lectures)
Review of internetworking (2 lectures)
Client-server computing (1 lecture)
Web technology (2 lectures)
Other Internet applications (1 lecture)
Secure servers (1 lecture)
Scalable and available servers (2 lectures)
RPC-based computing (1 lecture)
Internet startup guest lecture
Lecture 01, 20-755: The Internet, Summer 1999
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Internet history
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Sources:
– Leiner et. al, “A brief history of the Internet”,
www.isoc.org/internet-history/brief.html
– R. H. Zakon, “Hobbes’ Internet Timeline, v4.1”,
www.isoc.org/guest/zakon/Internet/History/HIT.html
– D. Comer, “The Internet Book, Sec. Edition”, PrenticeHall, 1997.
Lecture 01, 20-755: The Internet, Summer 1999
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ARPANET Origins
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1962
– J.C.R. Licklider (MIT) describes “Galactic Network”.
– Licklider becomes head of computer research at Defense
Advanced Research Program (DARPA) and convinces
eventual successor, Lawrence Roberts (MIT), among
others, of the importance of the concept.
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1964
– Leonard Kleinrock (MIT) publishes first book on packet
switching.
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1965
– Roberts and Thomas Merrill build first wide-area network
(using a dial-up phone line!) between MA and CA.
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1967
– Roberts (now at DARPA) publishes plan for “ARPANET”,
running at a blistering rate of 50 kbps.
Lecture 01, 20-755: The Internet, Summer 1999
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ARPANET Origins (cont)
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1968
– DARPA issues RFQ for the packet switch component.
– BBN (led by Frank Heart) wins contract and designs
switch called an Interface Message Processor (IMP)
– Bob Kahn (DARPA) works on overall ARPANET arch.
– Roberts and Howard Frank (Network Analysis Corp) work
on network topology and economics.
– Kleinrock (UCLA) builds network measurement system.
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1969
– First IMP installed at UCLA (first ARPANET node).
– Nodes added at SRI, UCSB, and Utah.
– By the end of the year the 4-node ARPANET is working,
with 56kbps lines supplied by AT&T
Lecture 01, 20-755: The Internet, Summer 1999
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ARPANET Origins (cont)
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1970
– BBN, RAND, and MIT added to ARPANET.
– Network Working Group (NWG), under Steve Crocker,
designed initial host-to-host protocol (NCP).
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1971
– 15 hosts: UCLA, SRI, UCSB, Utah, BBN, MIT, RAND, SDC,
Harvard, Lincoln Labs, UIUC, CWRU, CMU, NASA/Ames.
– Ray Tomlinson (BBN) writes first ARPANET email
program (origin of the @ sign).
– email becomes the first Internet killer app.
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Birth of Internetworking
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1972
– Kahn (DARPA) introduces idea of “open architecture
networking” :
» Each network must stand on its own, with no internal
changes allowed to connect to the Internet.
» Communications would be on a best-effort basis.
» “black boxes” (later called “gateways” and “routers”
would be used to connect the networks)
» No global control at the operations level.
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1973
– Metcalf and Boggs (Xerox) develop Ethernet.
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1974
– Kahn and Vint Cerf (Stanford) publish first details of TCP,
which is later split into TCP and IP in 1978.
Lecture 01, 20-755: The Internet, Summer 1999
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Birth of Internetworking
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~1980
– Berkeley releases open source BSD Unix with a TCP/IP.
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1982
– DARPA establishes TCP/IP as the protocol suite for
ARPANET, offering first definition of an “internet”.
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1983
– Jan 1: ARPANET switches from NCP to TCP/IP.
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1984
– Mockpetris (USC/ISI) invents DNS.
– Number of ARPANET hosts surpasses 1,000.
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1985
– symbolics.com becomes first registered domain name.
– other firsts: cmu.edu, purdue.edu, rice.edu, ucla.edu,
css.gov, mitr.org
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Birth of Internetworking
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1986
– NSFNET backbone created (56Kbps) between 5
supercomputing sites (Princeton, Pittsburgh, San Diego,
Ithica, Urbana), allowing explosion of University sites.
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1988
– Internet worm attack
– NSFNET backbone upgraded to T1 (1.544 Mbps).
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1989
– Number of hosts breaks 100,000.
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1990
– ARPANET ceases to exist.
– world.std.com becomes first commercial dial-up ISP.
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The Web changed everything...
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1991
– Tim Berners-Lee (CERN) invents the World Wide Web
(HTTP server and text-based Lynx browser)
– NSFNET backbone upgraded to T3 (44.736 Mbps).
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1993
– Mosaic WWW browser developed by Marc Andreessen
(UIUC)
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1995
– WWW traffic surpasses ftp as the source of greatest
Internet traffic.
– Netscape goes public.
– NSFNET decommissioned and replaced by
interconnected commercial network providers.
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1999
– MCI/Worldcom upgrades its US backbone to 2.5Gbps.
Lecture 01, 20-755: The Internet, Summer 1999
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Internet Domain Survey
(www.isc.org)
100,000,000
1,000,000
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Internet hosts
10,000,000
Lecture 01, 20-755: The Internet, Summer 1999
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Summary
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The Internet has had an enormous impact on
the world economy and day-to-day lives.
– mechanism for world-wide information dissemination.
– medium for collaboration and interaction without regard
to geographic location.
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One of the most successful examples of
government, university, and business
partnership.
– Possible only because of sustained government
investment and commitment to research and
development.
– Successful because of commitment by passionate
researchers to “rough consensus and working code”
(David Clarke, MIT)
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Break time!
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Dv: A toolkit for visualizing
massive remote datasets
David O’Hallaron
School of Computer Science and
Department of Electrical and Computer Engineering
Carnegie Mellon University
Institute for eCommerce, Summer 1999
Lecture 01, 20-755: The Internet, Summer 1999
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Internet service models
request
server
client
response
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Traditional lightweight service model
– small to moderate amount of computation to satisfy
requests
– e.g. serving web pages, stock quotes, online trading,
search engines
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Proposed heayweight service model
– massive amounts of computations to satisfy requests
– scientific visualization, data mining, medical imaging
Lecture 01, 20-755: The Internet, Summer 1999
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Lecture 01, 20-755: The Internet, Summer 1999
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Quake Project
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Carnegie Mellon
– David O’Hallaron (CS and ECE)
– Jacobo Bielak [PI] and Omar Ghattas (CivE)
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University of California Berkeley
– Jonathan Shewchuk (EECS)
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Southern California Earthquake Center
– Steve Day and Harold Magistrale (San Diego State)
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Kogakuin University, Tokyo
– Yoshi Hisada
Lecture 01, 20-755: The Internet, Summer 1999
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Teora, Italy
1980
Lecture 01, 20-755: The Internet, Summer 1999
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San Fernando Valley
lat. 34.38 long. -118.16
epicenter lat. 34.32 long. -118.48
x
San Fernando Valley
lat. 34.08 long. -118.75
Lecture 01, 20-755: The Internet, Summer 1999
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San Fernando Valley (top view)
Hard rock
x epicenter
Soft soil
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San Fernando Valley (side view)
Soft soil
Hard rock
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San Fernando Valley (side view)
Soft soil
Hard rock
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Initial node distribution
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Unstructured mesh
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Unstructured mesh (top view)
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Partitioned unstructured finite
element mesh of San Fernando
nodes
element
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Communication graph
Vertices: processors
Edges: communications
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Quake solver code
NODEVECTOR3 disp[3], M, C, M23;
MATRIX3 K;
/* matrix and vector assembly */
FORELEM(i) {
...
}
/* time integration loop */
for (iter = 1; iter <= timesteps; iter++) {
MV3PRODUCT(K, disp[dispt], disp[disptplus]);
disp[disptplus] *= - IP.dt * IP.dt;
disp[disptplus] += 2.0 * M * disp[dispt] (M - IP.dt / 2.0 * C) * disp[disptminus] - ...);
disp[disptplus] = disp[disptplus] / (M + IP.dt / 2.0 * C);
i = disptminus;
disptminus = dispt;
dispt = disptplus;
disptplus = i;
}
Lecture 01, 20-755: The Internet, Summer 1999
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Archimedes
www.cs.cmu.edu/~quake
Problem
Geometry (.poly)
Triangle/Pyramid
MVPRODUCT(A,x,w);
DOTPRODUCT(x,w,xw);
r = r/xw;
Finite element
algorithm (.arch)
Author
.c
Runtime library
.node, .ele
Slice
C compiler
a.out
.part
parallel system
.pack
Parcel
Lecture 01, 20-755: The Internet, Summer 1999
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Northridge quake simulation
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40 seconds of an aftershock from the Jan 17,
1994 Northridge quake in San Fernando Valley
of Southern California.
Model:
– 50 x 50 x 10 km region of San Fernando Valley.
– 13,422,563 nodes, 76,778,630 linear tetrahedral elements, 1
Hz frequency resolution, 20 meter spatial resolution.
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Simulation
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–
–
–
0.0024s timestep
16,666 timesteps (40M x 40M SMVP each timestep).
~15 GBytes of DRAM.
6.5 hours on 256 PEs of Cray T3D (150 MHz 21064 Alphas, 64
MB/PE).
– Comp: 16,679s (71%) Comm: 575s (2%) I/O: 5995s(25%)
– 80 trillion (10^12) flops (sustained 3.5 GFLOPS).
– 800 GB/575s (burst rate of 1.4 GB/s).
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Kobe 2/2/95 aftershock
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Kobe 2/2/95 aftershock
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Visualization of 1994
Northridge aftershock
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Visualization of 1994
Northridge aftershock
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Typical Quake viz pipeline
resolution
ROI
reading
interpolation
contours
isosurface
extraction
scene
scene
synthesis
local
display
and
input
rendering
remote
database
vtk library routines
FEM solver materials
engine
database
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Heavyweight grid service model
WAN
Remote compute hosts
(allocated once per service
by the service provider)
Lecture 01, 20-755: The Internet, Summer 1999
Local compute hosts
(allocated once per request
by the service user)
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Active frames
Active Frame Server
Input Active Frame
Frame
data
Frame
program
Output Active Frame
Active
frame
interpreter
Frame
data
Frame
program
Application
libraries
e.g, vtk
Host
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Overview of a
Dv visualization service
User
inputs
Display
Remote
dataset
Local
Dv
client
Request frame
Response
frames
Dv
Server
Resp.
frames
Dv
Server
...
Resp.
frames
Dv
Server
Resp.
frames
Dv
Server
(Request Server)
Remote DV Active Frame Servers
Lecture 01, 20-755: The Internet, Summer 1999
Local DV Active Frame Servers
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Grid-enabling vtk with Dv
request frame
[request server, scheduler, flowgraph, data reader ]
status
request server
reader
scheduler
local
Dv
client
result
...
...
response frames (to other Dv servers)
local
Dv
server
[native data, scheduler, flowgraph,control ]
remote machine
(Dv request server)
Lecture 01, 20-755: The Internet, Summer 1999
local machine
(Dv client)
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Scheduling Dv programs
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Scheduling at request frame creation time
– all response frames use same schedule
– performance portability (i.e. adjusting to heterogeneous
resources) is possible.
– no adaptivity (i.e., adjusting to dynamic resources)
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Scheduling at response frame creation time
– performance portability and limited adaptivity.
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Scheduling at response frame delivery time
– performance portability and greatest degree of adaptivity.
– per-frame scheduling overhead a potential disadvantage.
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Scheduling scenarios
Ultrahigh
Bandwidth
Link
low-end
remote
server
Lecture 01, 20-755: The Internet, Summer 1999
powerful
local
server
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Scheduling scenarios
High
Bandwidth
Link
high-end
remote
server
Lecture 01, 20-755: The Internet, Summer 1999
powerful
local
workstation
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Scheduling scenarios
Low
Bandwidth
Link
high-end
remote
server
Lecture 01, 20-755: The Internet, Summer 1999
local PC
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Scheduling scenarios
Low
Bw
Link
High
Bandwidth
Link
high-end
remote
server
Lecture 01, 20-755: The Internet, Summer 1999
powerful
local
proxy
server
low-end
local
PC or PDA
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Summary
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Heavyweight grid service model
– service providers can constrain resources allocated to a
particular service
– service users can contribute resources to improve response
time of throughput
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Active frames
– general software framework for providing heavyweight Internet
services
– framework can be specialized for a particular service type
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Dv
– specialized version of active frame server for vizualization
– grid-enables existing vtk toolkit
– flexible framework for experimenting with scheduling algs
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