Distributed Systems for System Architects

636 Pages·2001·28.941 MB·English

by  Paulo Veríssimo, Luís Rodrigues (auth.)

DISTRIBUTED SYSTEMS FOR
SYSTEM ARCHITECTS
ADVANCES IN
DISTRIBUTED COMPUTING AND
MIDDLEWARE
Consulting Editors
Prof. John A. Stankovic Dr. Richard E. Schantz
University ofVirginia Principal Scientist
Dept ofComputer Science BBN Technologies
Charlottesville, VA22903-2442 Cambridge, MA02138
[e-mail] [e-mail]
DISTRIBUTED SYSTEMS FOR
SYSTEM ARCHITECTS
by
Paulo Verissimo
University ofLisboa, Portugal
Luis Rodrigues
University ofLisboa, Portugal
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LibraryofCongressCataloging-in-PublicationData
Verfssimo,Paulo, 1956-
Distributedsystemsforsystemarchitects/PauloVerissimo,LuisRodrigues.
p.cm.--(Advancesindistributedcomputingandmiddleware;distl)
Includesbibliographicalreferencesandindex.
ISBN0-7923-7266-2(alk.paper)
1.Electronicdataprocessin--Distributedprocessing. I.Rodrigues,Luis, 1963-ll.
Title. ill.Series.
QA76.9.D5V452000
005'.36-dc21 00-052178
Copyright©2001 byKluwerAcademicPublishers
All rights reserved. No part ofthis publication may be reproduced, stored in a
retrieval system or transmitted in any form or by any means, mechanical, photo
copying,recording,orotherwise,withoutthepriorwrittenpermissionofthepublisher,
Kluwer Academic Publishers, 101 Philip Drive, Assinippi Park, Norwell,
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Printedonacid-freepaper.
PrintedintheUnitedStatesofAmerica
ThePublisheroffersdiscounts onthis bookfor courseuseandbulkpurchases.
Forfurtherinformation, sendemailto<[e-mail]>.
A
LUIsa, ao Tiago eao Vasco,
por esse ternpo,
em que 0 tempo era largo
To my parents, Vasco and Lurdes,
my sister, Elsa,
my wife, Ana,
and my children, Hugo and Sara
Contents
Preface xiii
Foreword XXI
Part I Distribution
1. DISTRIBUTED SYSTEMS FOUNDATIONS 3
1.1 A Definition of Distributed Systems 3
1.2 Services of Distributed Systems 10
1.3 Distributed System Architectures 11
1.4 Formal Notions 17
1.5 Summary and Further Reading 20
2. DISTRIBUTED SYSTEM PARADIGMS 21
2.1 Naming and Addressing 21
2.2 Message Passing 26
2.3 Remote Operations 28
2.4 Group Communication 31
2.5 Time and Clocks 35
2.6 Synchrony 43
2.7 Ordering 49
2.8 Coordination 60
2.9 Consistency 70
2.10 Concurrency 81
2.11 Atomicity 85
2.12 Summary and Further Reading 87
3. MODELS OF DISTRIBUTED COMPUTING 89
3.1 Distributed Systems Frameworks 89
3.2 Strategies for Distributed Systems 97
3.3 Asynchronous Models 101
3.4 Synchronous Models 103
vii
viii DISTRIBUTED SYSTEMSFORSYSTEMARCHITECTS
3.5 Classes of Distributed Activities 104
3.6 Client-Server with RPC 108
3.7 Group-Oriented 115
3.8 Distributed Shared Memory 123
3.9 Message Buses 129
3.10 Summary and Further Reading 131
4. DISTRIBUTED SYSTEMS AND PLATFORMS 133
4.1 Name and Directory Services 133
4.2 Distributed File Systems 139
4.3 Distributed Computing Environment (DCE) 146
4.4 Object-Oriented Environments (CORBA) 148
4.5 World-Wide Web 151
4.6 Groupware Systems 154
4.7 Summary and Further Reading 155
5. CASE STUDY: VP'63 159
5.1 Introduction 159
5.2 Initial System and First Steps 160
5.3 Distributed Computing Approaches 161
5.4 Distribution of Data Repositories 163
5.5 Distributed File System Access 166
Part II Fault Tolerance
6. FAULT-TOLERANT SYSTEMS FOUNDATIONS 171
6.1 A Definition of Dependability 171
6.2 Fault-Tolerant Computing 180
6.3 Distributed Fault Tolerance 186
6.4 Fault-Tolerant Networks 187
6.5 Fault-Tolerant Architectures 189
6.6 Summary and Further Reading 192
7. PARADIGMS FOR DISTRIBUTED FAULT TOLERANCE 193
7.1 Failure Detection 193
7.2 Fault-tolerant Consensus 201
7.3 Uniformity 203
7.4 Membership 204
7.5 Fault-Tolerant Communication 207
7.6 Replication Man;ai~ement in Partition-free Networks 216
7.7 Replication Management in Partitionable Networks 219
7.8 Resilience 222
7.9 Recovery 225
7.10 Summary and Further Reading 233
Contents ix
8. MODELS OF DISTRIBUTED FAULT-TOLERANT COMPUTING 235
8.1 Classes of Failure Semantics 235
8.2 Basic Fault tolerance Frameworks 238
8.3 Fault Tolerance Strategies 241
8.4 Fault-Tolerant Remote Operations 245
8.5 Fault-Tolerant Event Services 249
8.6 Transactions 250
8.7 Summary and Further Reading 258
9. DEPENDABLE SYSTEMS AND PLATFORMS 259
9.1 Distributed Fault-Tolerant Systems 259
9.2 Transactional Systems 265
9.3 Cluster architectures 266
9.4 Making Legacy Systems Dependable 267
9.5 Summary and Further Reading 269
10.CASE STUDY: VP'63 271
10.1 First Steps Towards Fault Tolerance 271
10.2 Fault-Tolerant Client-Server D'a'tabase 272
10.3 Fault-Tolerant Data Dissemination 273
10.4 Fault Tolerance of Local Servers 274
Part III Real-Time
11.REAL-TIME SYSTEMS FOUNDATIONS 277
11.1 A Definition of Real-Time 277
11.2 Real-Time Networks 283
11.3 Distributed Real-Time Architectures 285
11.4 Summary and Further Reading 287
12.PARADIGMS FOR REAL-TIME 289
12.1 Temporal Specifications 289
12.2 Timing Failure Detection 295
12.3 Entities and Representatives 296
12.4 Time-Value Duality 298
12.5 Real-Time Communication 300
12.6 Flow Control 302
12.7 Scheduling 302
12.8 Clock Synchronization 309
12.9 Input/Output 317
12.10Summary and Further Reading 320
13.MODELS OF DISTRIBUTED REAL-TIME COMPUTING 321
13.1 Classes of Timeliness Guarantees 321
x DISTRIBUTED SYSTEMS FORSYSTEM ARCHITECTS
13.2 Real-Time Frameworks 323
13.3 Strategies for Real-Time Operation 325
13.4 Synchronism Models Revisited 328
13.5 A Generic Real-Time System Model 330
13.6 The Event-Triggered Approach 331
13.7 The Time-Triggered Approach 334
13.8 Real-Time Communication Models 337
13.9 Real-Time Control 341
13.10Real-Time Databases 348
13.11Quality-of-Service Models 350
13.12Summary and Further Reading 353
14.DISTRIBUTED REAL-TIME SYSTEMS AND PLATFORMS 355
14.1 Operating Systems 355
14.2 Real-Time LANs and Field Buses 357
14.3 Time Services 359
14.4 Embedded Systems 361
14.5 Dynamic Systems 363
14.6 Real-Time over the Internet 365
14.7 Summary and Further Reading 366
15.CASE STUDY: VP'63 369
15.1 First Steps Towards Control and Automation 369
15.2 Distributed Shop-Floor Control 370
15.3 Integration ofthe Industrial System 371
Part IV Security
16.FUNDAMENTAL SECURITY CONCEPTS 377
16.1 A Definition of Security 377
16.2 What Motivates the Intruder 387
16.3 Secure Networks 388
16.4 Secure Distributed Architectures 390
16.5 Summary and Further Reading 393
17.SECURITY PARADIGMS 395
17.1 Trusted Computing Base 395
17.2 Basic Cryptography 396
17.3 Symmetric Cryptography 398
17.4 Asymmetric Cryptography 401
17.5 Secure Hashes and Message Digests 403
17.6 Digital Signature 404
17.7 Digital Cash 410
17.8 Other Cryptographic Algorithms and Paradigms 415
Contents xi
17.9 Authentication 417
17.10Access Control 421
17.11Secure Communication 425
17.12Summary and Further Reading 426
18.MODELS OF DISTRIBUTED SECURE COMPUTING 427
18.1 Classes of Attacks and Intrusions 427
18.2 Security Frameworks 433
18.3 Strategies for Secure Operation 436
18.4 Using Cryptographic Protocols 445
18.5 Authentication Models 451
18.6 Key Distribution Approaches 457
18.7 Protection Models 462
18.8 Architectural Protection: Topology and Firewalls 464
18.9 Formal Security Models 472
18.10Secure Communication and Distributed Processing 474
18.11Electronic Transaction Models 481
18.12Summary and Further Reading 485
19.SECURE SYSTEMS AND PLATFORMS 487
19.1 Remote Operations and Messaging 487
19.2 Intranets and Firewall Systems 495
19.3 Extranets and Virtual Private Networks 497
19.4 Authentication and Authorization Services 500
19.5 Secure Electronic Commerce and Payment Systems 502
19.6 Managing Security on the Internet 509
19.7 Summary and Further Reading 509
20.CASE STUDY: VP'63 511
20.1 First Steps Towards Security 511
20.2 Global Security: Extranet and VPN 513
20.3 Local Security: Intranet and Facility Gateway 513
Part V Management
21.FUNDAMENTAL CONCEPTS OF MANAGEMENT 519
21.1 A Definition of Management 519
21.2 Systems Management Architectures 524
21.3 Configuration of Distributed Systems 528
21.4 Summary and Further Reading 529
22.PARADIGMS FOR DISTRIBUTED SYSTEMS MANAGEMENT 531
22.1 Managers and Managed Objects 531
22.2 Domains 533