Distibuted Systems: Design and Algorithms

324 Pages·2011·5.355 MB·English

by  Serge Haddad, Fabrice Kordon, Laurent Pautet, Laure Petrucci

Distributed Systems
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Distributed Systems
design and algorithms

Edited by
Serge Haddad
Fabrice Kordon
Laurent Pautet
Laure Petrucci

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First published 2011 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as
permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced,
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The rights of Serge Haddad, Fabrice Kordon, Laurent Pautet and Laure Petrucci to be identified as the
authors of this work have been asserted by them in accordance with the Copyright, Designs and Patents
Act 1988.
____________________________________________________________________________________
Library of Congress Cataloging-in-Publication Data

Distributed systems : design and algorithms / edited by Serge Haddad ... [et al.].
p. cm.
Includes bibliographical references and index.
ISBN 978-1-84821-250-3
1. Electronic data processing--Distributed processing. 2. Peer-to-peer architecture (Computer networks)
3. Computer algorithms. 4. Embedded computer systems. 5. Real-time data processing. I. Haddad,
Serge.
QA76.9.D5D6144 2011
004'.33--dc22
2011012243

British Library Cataloguing-in-Publication Data
A CIP record for this book is available from the British Library
ISBN 978-1-84821-250-3

Printed and bound in Great Britain by CPI Antony Rowe, Chippenham and Eastbourne.

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Contents
Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Chapter1.Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
SergeHADDAD,FabriceKORDON,LaurentPAUTETandLaurePETRUCCI
FIRSTPART. LARGESCALE PEER-TO-PEER DISTRIBUTED SYSTEMS . . 19
Chapter2.IntroductiontoLarge-ScalePeer-to-PeerDistributedSystems 21
FabriceKORDON
2.1.“Large-Scale”distributedsystems? . . . . . . . . . . . . . . . . . . . . . 21
2.2.Consequencesof“large-scale” . . . . . . . . . . . . . . . . . . . . . . . 22
2.3.Somelarge-scaledistributedsystems . . . . . . . . . . . . . . . . . . . . 23
2.4.Architecturesoflargescaledistributedsystems . . . . . . . . . . . . . . 26
2.5.ObjectiveofPart1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.6.Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Chapter3.DesignPrinciplesofLarge-ScaleDistributedSystem . . . . . . 33
XavierBONNAIREandPierreSENS
3.1.Introductiontopeer-to-peersystems . . . . . . . . . . . . . . . . . . . . 33
3.2.Thepeer-to-peerparadigms . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.3.Servicesonstructuredoverlays . . . . . . . . . . . . . . . . . . . . . . . 41
3.4.BuildingtrustinP2Psystems . . . . . . . . . . . . . . . . . . . . . . . . 43
3.5.Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
3.6.Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Chapter4.Peer-to-PeerStorage . . . . . . . . . . . . . . . . . . . . . . . . . 59
OlivierMARIN,SébastienMONNETandGaëlTHOMAS
4.1.Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
v
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6 DistributedSystems
4.2.BitTorrent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4.3.Gnutella . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.4.Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
4.5.Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Chapter5.Large-ScalePeer-to-PeerGameApplications . . . . . . . . . . . 81
SébastienMONNETandGaëlTHOMAS
5.1.Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
5.2.Large-scalegameapplications:modelandspecificrequirements . . . . 83
5.3.Overviewofpeer-to-peeroverlaysforlarge-scalegameapplications . . 90
5.4.OverlaysforFPSgames . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
5.5.Overlaysforonlinelife-simulationgames . . . . . . . . . . . . . . . . . 95
5.6.Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
5.7.Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
SECOND PART. DISTRIBUTED, EMBEDDED AND REAL-TIME SYSTEMS . 105
Chapter6.IntroductiontoDistributed
EmbeddedandReal-timeSystems . . . . . . . . . . . . . . . . . . . . . . . . 107
LaurentPAUTET
6.1.Distributedreal-timeembeddedsystems . . . . . . . . . . . . . . . . . . 108
6.2.SafetycriticalsystemsasexamplesofDREsystems . . . . . . . . . . . 109
6.3.DesignprocessofDREsystems . . . . . . . . . . . . . . . . . . . . . . 112
6.4.ObjectivesofPart2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
6.5.Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Chapter7.SchedulinginDistributedReal-TimeSystems . . . . . . . . . . 117
EmmanuelGROLLEAU,MichaëlRICHARD,andPascalRICHARD
7.1.Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
7.2.Generalitiesaboutreal-timesystems . . . . . . . . . . . . . . . . . . . . 118
7.3.Temporalcorrectness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
7.4.WCRTofthetasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
7.5.WCRTofthemessages . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
7.6.Casestudy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
7.7.Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
7.8.Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Chapter8.SoftwareEngineeringforAdaptativeEmbeddedSystems . . . 159
EtienneBORDE
8.1.Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
8.2.Adaptation,anadditionalcomplexityfactor . . . . . . . . . . . . . . . . 160
8.3.Theoreticalaspectsofadaptationmanagement . . . . . . . . . . . . . . 163
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8.4.Technicalsolutionsforthedesignofadaptativeembeddedsystems. . . 171
8.5.Anexampleofadaptativesystemfromtheroboticdomain . . . . . . . 176
8.6.ApplyingMDEtechniquestothedesignoftheroboticuse-case . . . . 177
8.7.Exploitationofthemodels. . . . . . . . . . . . . . . . . . . . . . . . . . 184
8.8.Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
8.9.Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Chapter9.TheDesignofAerospaceSystems . . . . . . . . . . . . . . . . . . 191
MaximePERROTIN,JulienDELANGE,andJérômeHUGUES
9.1.Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
9.2.Flightsoftwaretypicalarchitecture . . . . . . . . . . . . . . . . . . . . . 193
9.3.Traditionaldevelopmentmethodsandtheirlimits. . . . . . . . . . . . . 195
9.4.ModelingasoftwaresystemusingTASTE:philosophy . . . . . . . . . 197
9.5.Commonsolutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
9.6.WhatTASTEspecificallyproposes . . . . . . . . . . . . . . . . . . . . . 200
9.7.Modelingprocessandtools . . . . . . . . . . . . . . . . . . . . . . . . . 201
9.8.Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
9.9.Modeltransformations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
9.10.TheTASTErun-time . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
9.11.Illustratingourprocessbydesigningheterogeneoussystems. . . . . . 215
9.12.FirstuserfeedbackandTASTEfuture . . . . . . . . . . . . . . . . . . 224
9.13.Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
9.14.Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
THIRDPART. SECURITY IN DISTRIBUTED SYSTEMS . . . . . . . . . . . . 229
Chapter10.IntroductiontoSecurityIssuesinDistributedSystems . . . . 231
LaurePETRUCCI
10.1.Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
10.2.Securedataexchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
10.3.Securityinspecificdistributedsystems . . . . . . . . . . . . . . . . . . 234
10.4.OutlineofPartIII . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
10.5.Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Chapter11.PracticalSecurityinDistributedSystems . . . . . . . . . . . . 237
BenoîtBERTHOLON,ChristopheCÉRIN,CamilleCOTI,
Jean-ChristopheDUBACQ andSébastienVARRETTE
11.1.Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
11.2.Confidentiality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
11.3.Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
11.4.Availabilityandfaulttolerance . . . . . . . . . . . . . . . . . . . . . . 261
11.5.Ensuringresourcesecurity . . . . . . . . . . . . . . . . . . . . . . . . . 278
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8 DistributedSystems
11.6.Resultcheckingindistributedcomputations . . . . . . . . . . . . . . . 283
11.7.Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
11.8.Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
Chapter12.EnforcingSecuritywithCryptography . . . . . . . . . . . . . . 301
SamiHARARIandLaurentPOINSOT
12.1.Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
12.2.Cryptography:fromageneralperspective . . . . . . . . . . . . . . . . 303
12.3.Symmetricencryptionschemes . . . . . . . . . . . . . . . . . . . . . . 308
12.4.Primenumbersandpublickeycryptography. . . . . . . . . . . . . . . 324
12.5.Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
12.6.Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
List of Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
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Foreword
Itishardtoimaginetodayasinglecomputationthatdoesnotrelyonatleastone
distributed system directly or indirectly. It could be a distributed file system, a dis-
tributeddatabase,acontentdistributionnetwork,apeer-to-peergame,aremotemal-
waredetectionservice,asensornetwork,oranyotherdistributedcomputation. Dis-
tributedsystemshavebecometheequivalentofeconomicglobalizationinthe world
ofcomputing. Adoptedforeconomicreasons,poweredbyhighlyefficientandubiq-
uitousnetworking,distributedsystemsdefinethedefaultarchitectureforalmostevery
computinginfrastructureinusetoday.
Overthelasttwodecades,distributedsystemshavetakenmanyshapesandforms.
Clusters of computers were among the earliest generations of distributed systems,
whose goal was to provide a cost-effective alternative to highly expensive parallel
machines. File serverswerefirsttoevolvefromthecluster-baseddistributedsystem
model to serve an increasing hunger for storage. The World Wide Web introduced
thewebserverand,withit,theclient-serverdistributedsystemmodel,onwhichmil-
lionsofotherInternetserviceshavebeenbuilt. Peer-to-peersystemsappearedasan
“anti-globalizationmovement”,infactananti-corporateglobalizationmovementthat
foughtagainstthemonopolyoftheserviceproviderintheclient-servermodel.Cloud
computingturneddistributedsystemsintoautilitythatofferscomputingandstorage
as services over the Internet. One of the emerging and least expected beneficiaries
of cloudcomputingwill be the mobileworld of smartphonesand personaldevices,
whoseresourcelimitationcanbesolvedthroughcomputationoffloading.Attheother
end, wireless networking has initiated the use of distributed systems in sensor net-
worksandembeddeddevices. Finally,onlinesocialnetworkingisprovidinganovel
usefordistributedsystems.
With this multitudeof realizations, distributed systems have generateda rich set
of research problemsand goals. Performancewas the first one. However, although
the performanceof distributed systems has increased, there has been a resultant in-
crease in the programming burden. For a decade, research in distributed systems
ix
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10 DistributedSystems
had tried to reconcile performanceand programmabilityby making the distribution
of computation transparent to the programmer through software distributed shared
memory. Intheend,thingshavenotbecomesimplerasachievingperformanceunder
distributedsharedmemorycomeswithanon-negligiblesemanticcostcausedbythe
relaxedmemoryconsistencymodels.
With theshiftofdistributedsystemstowardsfile systemsandInternet-basedser-
vices,theresearchchangedfocusfromperformancetofaulttoleranceandavailability.
More recently, the ubiquity of distributed system architecture has resulted in an in-
creasedresearchinterestinmanageabilityaspects. Concernsofsustainabilityresulted
inenergy-awaredistributedservers,whichessentiallyproposeddynamicreconfigura-
tion for energysaving withoutperformanceloss. In the mobile arena, wireless net-
working introduced the important issues of location-awareness, ad-hoc networking,
anddistributeddatacollectionandprocessing. Finally,ascomputationandstorageis
increasinglyoffloadedtothecloud,issuesofsecurityandprivacyhaverecentlygained
momentum.
Thisbookisajourneyintothreedomainsofthisvastlandscapeofdistributedsys-
tems:large-scalepeer-to-peersystems,embeddedandreal-timesystems,andsecurity
indistributedsystems. Theauthorshaverecognizedexpertiseinallthreeareas,and,
moreimportantly,theexperienceofbuildingrealdistributedsystems. Thisbookre-
flects the expertiseof its authorsbybalancingalgorithmsand fundamentalconcepts
withconcreteexamples.
Peer-to-peersystemshavegenerateda certainfascinationamongstresearchers. I
seeatleasttworeasonsforthis. First,peer-to-peersystemscomefromthepositionof
thechallengerwhowantstotakeawaythecrownfromthelong-reigningclient-server
model. Essentially, the challenge is whether it is possible for a democratic society
of systems to function efficiently without leadership. I am not sure whether history
has ever proven that this is possible, but the peer-to-peer systems researchers have
shown it to be possible. They employedefficient peer-to-peerdata structurescalled
distributedhashtables(DHT)toachievescalabledataretrievalwhenpeerscomeand
go,failormisbehave.
Tribalinstinctmightalsoberesponsibleforourinterestinpeer-to-peersystems:it
ismorelikelytoseekhelpfromourpeerswheneverpossibleratherthanfromtheout-
siders. Thismayexplainthepopularityofpeer-to-peerapplications,suchasGnutella,
BitTorrent,andthepeer-to-peergamesdiscussedinthebook,someofthem(Gnutella)
developed even before researchers showed how to design peer-to-peer systems effi-
ciently.
However,takeheed,occasionally,peer-to-peersystemscanbeanillusion.Popular
socialnetworkstodaymaylooklike peer-to-peersystemsto the user, but, in reality,
their implementationis heavily centralized. Recent concernsof data ownership and
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Foreword 11
privacy have triggered an appetite for building truly peer-to-peer online social net-
works. Itisbettertounderstandhowpeer-to-peersystemsworkratherthanbefooled
again.
Thedistributedembeddedandreal-timesystems, whichmakethe middlepartof
the book, take distributed systems’ computing labs or centers, into the real, uncon-
trollableworld. Whetherembeddedincars,buildings,orourownbodies,embedded
systemsmustfunctionwithoutcontinuousoperatorassistance,adaptingtheirfunction-
alitytothechangingdemandsofthephysicalsystemstheyassistorcontrol. Physical
systems may also incorporate highly inter-connected embedded computers in order
tobecomecyber-physicalsystems. Computerscientistshavealwaysbeengoodatde-
signingsystemsforthemselves:languages,operatingsystems,andnetworkprotocols.
However,embeddedsystemsareaboutothers.Theyrepresentaprerequisiteinimple-
mentingMarkWeiser’svisionofpervasivecomputing,accordingtowhichcomputers
willnotjustbecomeubiquitous,butalsoinvisible.
Embeddedcomputingoftendemandsreal-timeguarantees,arequirementthathas
beenshowntobechallengingforanykindofcomputing,notjustfordistributedsys-
tems.Thispartofthebookcoversdistributedreal-timesystems,howtobuildadaptive
embedded systems from a software engineering perspective, and concludes with an
interestingreal-worldexampleofsoftwaredesignforan aerospacesystemusingthe
modelingtooltheydeveloped. Afterreadingthisbook,wheneveryoufly, I amsure
youwillhopethattheengineerwhodesignedtheplane’ssoftwarehasreadittoo.
Finally,thelastpartofthebookcoverssecurityindistributedsystems. Distributed
systemsinherentlyrequiresecurity.Whethertheyareclientsandserversorjustpeers,
these parties, as in reallife, rarelytrust each other. The authorspresentkey aspects
of grid systems’ security and dependability such as confidentiality, authentication,
availability,andintegrity.Withtheincreasingpopularityofcloudcomputing,security
andprivacyissueswillbeanevengreaterconcern.Virtualmachineenvironmentsare
shownnottobesufficientlytrustworthyaslongastheyareinthehandsofthecloud
providers. Users are likely to ask for stronger assurances, which may come from
usingtheTrustedPlatformModule(TPM)support,presentedinthisbook,aswellas
from intelligent auditing techniques. The book’s last section is about cryptography,
the mystical part of computer science, which we always rely on when it comes to
protectingtheconfidentialityofourcommunications.
Whoshouldreadthebook? Theauthorsrecommenditforengineersandmasters
students. I am inclined to agree with them that this book is certainly not for the
inexperienced. Itrequiressomebackgroundknowledge,butalsothematuritytoread
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