Al Aho
aho@cs.columbia.edu
Effective Software Systems
Research
Bell Labs
December 6, 2013
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What it means to be a systems researcher
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Outline
1. Forces shaping the global information networking
infrastructure
2. Necessary ingredients for research effectiveness
3. NSF CISE Advisory Council 2025 vision
4. The bottom line
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Forces Shaping the Network
• Explosion of diverse end devices
• Shift towards ultra-fast access
• Ultra-fast IP network
• Billions of new cloud services
• Rapid deployment of cloud services
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A World Connected: 2.4B Internet Users 6/30/2012*
Al Aho
HTTP 0.9
Mosaic Browser
RFC 675 TCP/IP
ARPANet
1969 1974
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World Wide Web
Internet
1989
* www.internetworldstats.com
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Credit: Intel Corporation
Cellular Networks, Mobile Devices and
Pervasive Computing
• Mobile phones are the only digital system accessible to the
majority of the planet.
– 6.8 billion mobile phone connections globally.
– 85% of new handsets will be able to access the mobile web: 1 in
5 has access to fast service, 3G or better; 10 trillion messages
by 2013.
• Growing ecosystem of tools and applications:
– Banking, commerce, healthcare, social networking:
1M distinct active apps just in App Store.
– Mobile browsers can now display much of the content available
to their desktop counterparts.
• Mobile payment systems are now common in the developing world.
– Sensitive and private data stored & entered on devices.
Image Credit: Nicolle Rager Fuller,
NSF
Research Themes:
Infrastructure
scalability
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Spectrum
management
Security and
privacy
Energy
consumption
Advanced
networking
technologies
F. Jahanian, NSF
Qatar ARC’13
Available/Emerging Networking Technologies
• Access
– Ultrabroadband
– FTTX
• Networking infrastructure
– IP bearer service
– Software defined networks
– OpenFlow
– Network Functions Virtualization
– Cloud computing
– Content-delivery networks
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Business Challenges
• Services and content from whose data centers?
• More diverse devices but at a lower cost per device
• More bandwidth but at a lower cost per bit
• Seamless unification of disparate networks
• Hosting, creating and delivering huge numbers of new
services but with lower management costs
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Cross-cutting Business Issues
• Role of content
• Better security and privacy
• Reducing energy consumption
• Reducing network complexity
• Improving software quality
• Regulatory issues
• Convergence and interoperability of infrastructures
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Software Systems
The world depends on software but most people are
not aware of how much software there already is,
or how expensive it is to develop and maintain, or
how hard it is to get it right.
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Software, Software Everywhere
“A conservative estimate is that the world is already
using hundreds of billions of lines of software to
conduct its affairs.”
A. V. Aho
Software and the Future of Programming Languages
Science, February 27, 2004, pp. 1131-1133
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IEEE Spectrum Software Hall of Shame
Year
Company
Costs in US $
2004
UK Inland Revenue
Software errors contribute to
$3.45 billion tax-credit
overpayment
2004
J Sainsbury PLC [UK]
Supply chain management
system abandoned after
deployment costing $527M
2002
CIGNA Corp
Problems with CRM system
contribute to $445M loss
1997
U. S. Internal Revenue
Service
Tax modernization effort
cancelled after $4 billion is
spent
1994
U. S. Federal Aviation
Administration
Advanced Automation System
canceled after $2.6 billion is
spent
R. N. Charette, Why Software Fails, IEEE Spectrum, September 2005.
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J. D. Zients On Government IT Projects
“[Government] IT projects too often cost hundreds of
millions of dollars more than they should, take years
longer than necessary to deploy and deliver
technologies that are obsolete by the time they are
completed.”
Jeffrey D. Zients
Management Consultant and Future Economic Advisor
Obama White House
From a 2010 internal government memo
Quoted on the front page of the NY Times
Monday, November 11, 2013
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Effective Software Systems Research
• Two aspects of systems research
– Experimental
– Theoretical
• But
“If you find that you're spending almost all your time on
theory, start turning some attention to practical things;
it will improve your theories. If you find that you're
spending almost all your time on practice, start turning
some attention to theoretical things; it will improve your
practice.” − Don Knuth
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Theory in Practice: Regular Expression Pattern
Matching in Perl, Python, Ruby vs. AWK
Time to check whether a?nan matches an
regular expression and text size n
Russ Cox
Regular expression matching can be simple and fast (but is slow in Java, Perl, PHP, Python, Ruby, ...)
[http://swtch.com/~rsc/regexp/regexp1.html, 2007]
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What is Effective Software Systems Research?
Research that leads to software systems that have a
major impact.
Impact can take a variety of forms:
– connecting people, e.g. WWW and the Internet
– transforming an existing area, e.g. spreadsheets for accounting
– creating a new company, e.g. Google search
– realigning a corporate strategic plan, e.g. in 1991 Bill Gates
realigns Microsoft to pursue an intelligent Internet
– creating new knowledge, e.g. RSA encryption algorithm
– giving your employer a decided advantage in the marketplace
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Traditional Metrics of Scholarly Effectiveness
• Citations
• Publications in influential journals & conferences
• Awards and honors
• Opinion of peers in letters and interviews
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Additional New Metrics
• Article downloads and views
• Influence on policy makers
• Effects on industry and the economy
• Public outreach
The maze of impact metrics
Editorial, Nature, October 16, 2013
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Examples of Effective Software Systems Research
1. First modern personal computer (Thacker; Xerox PARC)
2. TCP/IP (Cerf and Kahn; DARPA)
3. Public-key cryptography (Rivest, Shamir, Adleman; MIT)
4. OO programming (Dahl and Nygaard; Norwegian Computer Center)
5. Transaction processing (Gray; IBM)
6. Interactive computing (Englebart; SRI)
7. Distributed personal computing environments (Lampson; Xerox PARC)
8. Computer graphics (Sutherland; MIT)
9. Unix and C (Thompson and Ritchie; Bell Labs)
10. Relational model of data (Codd; IBM)
ACM A. M. Turing Award Winners
acm.org
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More Examples of Effective Software Systems
1. LLVM (compiler infrastructure written in C++; UIUC)
2. Eclipse (multilanguage IDE written in Java; IBM Canada)
3. VMware (virtualization technology)
4. Secure Network Programming (secure sockets; UT Austin)
5. MAKE (build utility; Bell Labs)
6. Java (general purpose OO language; SUN)
7. SPIN (software model checking system; Bell Labs)
8. The S System (statistical programming language; Bell Labs)
9. NCSA Mosaic (multiplatform browsing tool; NCSA, UIUC)
10. WWW (network-oriented hypermedia system; CERN)
ACM Software System Awards
acm.org
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Effective Programming Languages
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1. C
6. C#
2. Java
7. (Visual) Basic
3. Objective-C
8. Python
4. C++
9. Transact-SQL
5. PHP
10.JavaScript
Al Aho
Tiobe Programming Community Index
www.tiobe.com
November 2013
Three Necessary Ingredients for Effectiveness
1. Your idea should solve an important problem
• George Heilmeier: “Answer my catechism questions!”
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The Heilmeier Catechism Questions
1. What are you trying to do? Articulate your
objectives using absolutely no jargon.
2. How is it done today and what are the limits to
current practice?
3. What’s new in your approach and why do you think
it will be successful?
4. Who cares?
5. If you are successful, what difference will it make?
George H. Heilmeier
6. What are the risks and the payoffs?
7. How much will it cost?
8. How long will it take?
9. What are the midterm and final “exams” to check
for success?
http://en.wikipedia.org/wiki/George_H._Heilmeier
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Three Necessary Ingredients for Effectiveness
1. Your idea should solve an important problem
• George Heilmeier: “Answer my catechism questions!”
2. You need to teach others how to use your idea
• Richard Hamming: “You not only need to do good work you
must also teach others how to use your work.”
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Three Necessary Ingredients for Effectiveness
1. Your idea should solve an important problem
• George Heilmeier: “Answer my catechism questions!”
2. You need to teach others how to use your idea
• Richard Hamming: “You not only need to do good work you
must also teach others how to use your work.”
3. To be effective in the near future your idea needs a
route to the sea
• AWK case study
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AWK: a simple pattern-action language for
common data-processing applications
Paradigm problem: Given a list of name-value pairs, print the total
value associated with each name.
alice 10
eve 20
bob 15
alice 30
eve 20
bob 15
alice 40
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AWK: a simple pattern-action language for
common data-processing applications
Paradigm problem: Given a list of name-value pairs, print the total
value associated with each name.
alice 10
eve 20
bob 15
alice 30
An AWK program
is a sequence of
pattern-action statements
{ total[$1] += $2 }
END { for (x in total) print x, total[x] }
eve 20
bob 15
alice 40
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AWK’s Route to the Sea
• AWK solved common data-processing problems simply
• AWK came with Unix and was easy to combine with other
UNIX commands
• AWK was (and still is!) small and easy to learn
• On-line man page, tutorials and book showed how to use
AWK to solve practical problems
• An initial set of enthusiastic AWK users provided
valuable feedback and acted as evangelists
• We evolved AWK over a decade to meet new user needs
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Inspiring Innovation: The Programming
Languages and Translators Course at
Columbia University
• In PLT you will learn the syntactic and semantic elements and the
computational models of the most important modern programming
languages as well as the algorithms and techniques used by
compilers to translate them into machine and other target
languages. The course will cover imperative, object-oriented,
functional, logic, and scripting languages, as well as trends in the
evolution of programming languages.
• A highlight of this course is a semester-long programming project
in which you will work in a small team to create and implement an
innovative little language of your own design. This project will
teach you computational thinking in language design as well as
project management, teamwork, and communication skills that
you can apply in all aspects of your career.
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A Sampling of PLT Languages
What to Wear: personalized wardrobe recommendations
Swift Fox: configuring wireless sensor networks
Trowel: a webscraping language for journalists
Upbeat: a language for auralizing data
Suds: a language for shared-session telecom services
Q-HSK: a language for teaching quantum computing
http://www.cs.columbia.edu/~aho/cs4115/
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Phases of a Compiler
source
program
Lexical
Analyzer
target
program
Syntax
Analyzer
token
stream
Semantic
Analyzer
syntax
tree
Interm.
Code
Gen.
annotated
syntax
tree
Symbol Table
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Code
Optimizer
interm.
rep.
interm.
rep.
Code
Gen.
Front End Compiler Component Generators
source
program
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lex
specification
yacc
specification
Lexical
Analyzer
Generator
LEX
Syntax
Analyzer
Generator
YACC
Lexical
Analyzer
token
stream
Syntax
Analyzer
syntax
tree
The PLT Course Project at Columbia
Week Task
2
Form a team of five and design an innovative new language
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4
Write a whitepaper on your proposed language modeled after
the Java whitepaper
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Write a tutorial patterned after Chapter 1 and a language
reference manual patterned after Appendix A of Kernighan
and Ritchie’s book, The C Programming Language
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Give a ten-minute presentation of your language to the class
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Give a 30-minute working demo of your compiler to the
teaching staff
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Hand in the final project report
Al Aho
Individual Roles on the Project Team
• Project manager
– sets the project schedule, holds weekly meetings with the entire team,
maintains the project log, and makes sure the project deliverables get
done on time.
• Language and tools guru
– defines the baseline process to track language changes and maintain
the intellectual integrity of the language.
– teaches the team how to use various tools used to build the compiler.
• System architect
– defines the compiler architecture, modules, and interfaces.
• System integrator
– defines the system platform and makes sure the compiler components
work together.
• Tester and validator
– defines the test suites and executes them to make sure the compiler
meets the language specification.
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Telling Lessons Learned by PLT Students
• “Designing a language is hard and designing a simple
language is extremely hard!”
• “During this course we realized how naïve and
overambitious we were, and we all gained a newfound
respect for the work and good decisions that went into
languages like C and Java which we’ve taken for
granted for years.”
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Where is the Future Headed?
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Bell’s Law: Birth and Death of
Computer Classes
Computers
Per Person
1:106
Mainframe
Mini
1:103
Workstation
PC
Laptop
1:1
PDA
Cell
103:1
years
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Mote
???
G. Bell
Bell’s Law for the Birth and Death of Computer Classes
CACM, Jan 2008, pp. 86-94
Innovation Drivers/Trends for 2025
• Extreme personalization
– Health/medical, career, mobility, lifestyle, education, language,
data, entertainment, …
• Extreme augmentation
– Memory (perfect), data (always accessible and unbounded),
communication (always on), analytics (as/when needed, AI/ML
on demand…), multi-locations (virtual presence), …
• Extreme human-world integration
– In-body devices (vs. on-body or external), brain and sensorial
interfaces, seamless virtual+real worlds …
– Collective systems (e.g. crowdsourcing), assisted+assistive
robotics, “green” living, disaster management …
Vision 2025
NSF CISE AC
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The Dark Side of the Internet: Rise of Politically
Motivated Attacks, Cyber War, Censorship,
Hacktivism and Cyber Espionage
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Cyber Security Challenges
• Attacks and defenses co-evolve: a system that was secure
yesterday might no longer be secure tomorrow.
• The technology base of our systems is frequently updated to
improve functionality, availability, and/or performance. New
systems introduce new vulnerabilities that need new defenses.
• The environments in which our computing systems are
deployed and the functionality they provide are dynamic, e.g.
cloud computing, mobile platforms.
Image Credit: ThinkStock
• As automation pervades new platforms, vulnerabilities will be
found in critical infrastructures, automotive systems, smart
grids, medical devices, transportation systems.
• The sophistication of attackers is increasing as well as their
sheer number and the specificity of their targets.
• Cyber security is a multi-dimensional problem requiring
expertise from computer science, mathematics, economics,
public policy, behavioral and social sciences.
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F. Jahanian, NSF
Qatar ARC’13
The Bottom Line
Software systems will play a key role in shaping
the technology and industry structure of the
global information infrastructure of the future.
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But Most Importantly
You can’t do effective software systems research
without a critical mass of great software systems
researchers.
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Al Aho
aho@cs.columbia.edu
Effective Software Systems
Research
Bell Labs
December 6, 2013
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