JAIST Repository
https://dspace.jaist.ac.jp/Title

Challenges Toward a Dependable Infrastructure fora Trustworthy e‑SocietyAuthor(s)DEFAGO, Xavier

CitationIssue Date

2005‑03‑11

TypePresentation

Text version

publisher

URL

http://hdl.handle.net/10119/8278

RightsDescription

JAIST 21世紀COEシンポジウム2005「検証進化可能電子社会」 = JAIST 21st Century COE Symposium 2005
Verifiable and Evolvable e‑Society , 開催
：2005年3月10日〜11日, 開催場所：石川ハイテク交流センター, Technical session 5 <Dependable
Infrastructure>

Japan Advanced Institute of Science and Technology

SomeMotivation

Challenges Toward a

Dependable Infrastructure
for a Trustworthy e-SocietyOur Society
BOOMXavier DÉFAGO
School of Information Science,
Japan Adv. Inst. of Science & Tech. (JAIST)
PRESTO, Japan Science & Tech. Agency (JST)Social Infrastructure Information System
ATCHA!

BOOM!"#$%&'$($%)

1994 Deneba Systems, Inc.

1994 Deneba Systems,
1994 Deneba
Inc.
Systems, Inc.

1994 Deneba Systems, Inc.

1994 Deneba Systems, Inc.

2

Context: e-Society

Goal
Dependable Infrastructure
for a Trustworthy e-Society• Characteristics• very heterogeneous• very large scale• very dynamic••••• Dependable Infrastructure

Our Society• Mechanisms, methodologies for dependable infrastructuresRequirements
correctness, accountability
availability, reliability,robustness
adaptability, evolvability

Social Infrastructure Information System• Trustworthy e-Society• Face new challenges

3Outline4

Dependable Systems• Background• Dependability• Dependability• Agreement• errors & faults can occur anywhere at any time
• they should have little or no consequence• Challenges with e-Society• Means• multi-levels guarantees• heterogeneity• scalability• prevention (specification, verification, testing)• masking (redundancy, resilience)• recovery (checkpointing, reparation)• Conclusion

56

Dependability
in Distributed Systems

Dependable e-Society• e-Society is a System• CorrectnessBOOM• Behavior corresponds to specification• Specification corresponds to expectations• Dependability• Reliability: e-Society does not fail.
• Availability: e-Society responds when I needed it.
• Accountability: e-Society can report on actions/decisions.
• Privacy: e-Society protects private sphere.
• Fairness: e-Society maintains fairness / transparency.

Systems• Distributed
Entities/services, communication•• Interactions

78Agreement Protocol(e.g., Consensus)

Agreement as Foundation• Agreement• Interact to reach commondecisions• E.g., elections, ...
• Also between sub-systems

integration• Applicationsorganization

p1

v1

p2

v2

p3

v3

cooperation

Agreementv = v2

Consensus
BOOMpropose(vi )• Consensus,• Atomic multicast,• Atomic commit,• Service replication, ...

decide(v)• Definition
Participants propose value•• Agreement on decision value

9

Challenge 1:

10

Challenge 1:

multi-perspective guarantees

multi-perspective guarantees• Traditional systems• computer service: client / server• guarantees for servers• guarantees for clients

1994 Deneba Systems, Inc.

Our Society• e-Society infrastructure• system perception includes other “clients”• people also part of the system.

Social Infrastructure Information System• Difficulty• Manage interactions between machines and people• Provide guarantees from different viewpoints
1112Challenge 2:

Mobility & Agreement

heterogeneity• Active components

Agreement• computers, servers• electronic appliances• vehicles, transportation systems• robots• people• Mobility• mobility as “input”• mobility as “output”• Agreement
Group behaves as single entity•• Many kinds of agreement

13

Challenge 3:

Mobility & Agreement
coordinate system(“x-y-z”)• problem is trivial• ... modulo errors

scalability• “Big numbers”• Agreement on• with GPS14zxyx• many participants• high activity• large amounts of data & computation• large distanceszy• Effect• complex interactions• efficiency/performance issues• with landmarks• problem is easy

• no GPS, no landmarks• Actions• problem is very hard
• or even impossible• combination / integration of techniques• good abstractions, scalable protocols

15Conclusion• Trustworthy e-Society• More and more reliance on e-Society• Dependability essential for deserving trust• People are big part of the game

• Research• Builds upon state-of-the-art• Many new challenges• Highly interdisciplinary1716