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Architecture and Methods for Flexible Content Management in Peer-to-Peer Systems
Udo Bartlang
Verlag Vieweg+Teubner (GWV), 2010
ISBN 9783834896452 , 240 Seiten
Format PDF, OL
Kopierschutz Wasserzeichen
Geräte
Foreword
6
Danksagung
8
Abstract
9
Zusammenfassung
11
Contents
13
List of Figures
17
List of Tables
19
1 Introduction
20
1.1 Sample Scenarios of a Peer–to–Peer-Based Content Repository
22
1.1.1 Cross-Enterprise Business Collaboration
22
1.1.2 Intra-Enterprise Knowledge Management
25
1.2 Problem Statement and Research Challenges
29
1.2.1 Research Challenges Regarding the Content Model
30
1.2.2 Research Challenges Regarding the Content Repository Model
30
1.2.3 Research Challenges Regarding the Peer–to–Peer Model
32
1.3 Main Research Contributions of this Thesis
33
1.4 Publications
35
1.5 Outline
36
2 Background
38
2.1 Content Repositories
39
2.1.1 Content versus Data
41
2.1.2 Content Management
42
2.1.3 Content Management Systems
42
2.2 Distributed Systems, Algorithms, and Methods
44
2.2.1 Node Model
45
2.2.2 Communication Models
45
2.2.3 Failure Models
47
2.2.4 Consensus Algorithms
48
2.2.5 Fault-Tolerant State Machines
50
2.2.6 Group Communication
51
2.2.7 Dynamic Code Loading
51
2.3 Peer–to–Peer Systems
52
2.3.1 Centralised Peer–to–Peer Overlays
53
2.3.2 Unstructured Peer–to–Peer Overlays
54
2.3.3 Structured Peer–to–Peer Overlays
55
2.4 Distributed File Systems
56
2.4.1 Client–Server-Based Systems
57
2.4.2 Peer–to–Peer-Based Systems
59
2.5 Distributed Database Systems
61
2.5.1 Client–Server-Based Systems
62
2.5.2 Peer–to–Peer-Based Systems
64
2.6 Summary
65
3 Analysis of Content Repository Requirements in a Peer–to–Peer Case
67
3.1 Methodology of Analysis
67
3.2 Definition of Functional Building Blocks Using the Content Repository API for Java Technology
68
3.2.1 Content Repository Model
69
3.2.2 Content Repository Functions
71
3.2.3 Operational Scope
79
3.3 Dependence Relationships between Functional Building Blocks
80
3.3.1 Service Functionality Dependence
80
3.3.2 Influence Dependence
82
3.4 Suitability of Peer–to–Peer Overlays for Content Repository Functionality
83
3.4.1 Functional Content Repository Requirements for a Peer–to–Peer Approach
84
3.4.2 Non-Functional Content Repository Requirements for a Peer–to–Peer Approach
84
3.5 Summary
86
4 Design of a Generic Peer–to–Peer Content Repository System Architecture
88
4.1 Architectural Model
89
4.1.1 Logical View
89
4.1.2 Process View
89
4.1.3 Development View
90
4.1.4 Physical View
90
4.1.5 Scenarios
90
4.2 Generic Content Repository Architecture
91
4.2.1 Modular Decomposition
91
4.2.2 Persistent Storage Management
94
4.3 Generic Content Mapping
97
4.3.1 Item Naming Concept
97
4.3.2 Flexible Content Item Policies
100
4.4 Generic Peer Architecture
101
4.4.1 Internal Peer Structure
101
4.4.2 Dynamic Service Integration
104
4.5 Related Work
106
4.6 Summary
108
5 Methods for Flexible Content Repository Functions in Structured Peer–to–Peer Overlays
109
5.1 DhtFlex: A Distributed Algorithm for Flexible Atomic Data Management
109
5.2 System Context of DhtFlex
111
5.2.1 System Model
111
5.2.2 System Architecture
112
5.2.3 System Interface
116
5.3 Functionality of DhtFlex
116
5.3.1 Annotated Data Resources
117
5.3.2 Recast Case
117
5.3.3 Put Case
123
5.3.4 Get Case
125
5.3.5 Overlay Breakup Detection
127
5.4 Flexible Content Repository Functions
128
5.4.1 Content Mapping
128
5.4.2 Persistent Content Storage
130
5.5 Related Work
133
5.6 Summary
135
6 Methods for Flexible Content Repository Functions in Hybrid Peer–to–Peer Overlays
136
6.1 Reconfigurable Peer–to–Peer Service Groups
137
6.2 System Context of Peer–to–Peer Service Groups
139
6.2.1 System Model
139
6.2.2 System Architecture
140
6.2.3 System Interface
144
6.3 Functions of Peer–to–Peer Service Groups
145
6.3.1 Lifecycle Management
145
6.3.2 Decentralised Dynamic Code Loading of Service Functions
149
6.3.3 Consensus-Based Peer–to–Peer Group Communication
154
6.4 Flexible Content Repository Functions
163
6.4.1 Content Mapping
163
6.4.2 Persistent Content Storage
165
6.5 Related Work
168
6.6 Summary
171
7 Evaluation
173
7.1 Methodology
173
7.1.1 Architecture Evaluation
173
7.1.2 Method Evaluation
175
7.2 Peer–to–Peer Content Repository System Architecture
176
7.2.1 Architectural Styles
176
7.2.2 Quality Attributes
177
7.2.3 Scenarios
179
7.3 Methods for Flexible Content Repository Functions in Structured Peer–to–Peer Overlays
181
7.3.1 Reliability
181
7.3.2 Consistency
183
7.3.3 Reconfigurability
192
7.3.4 Scalability
192
7.3.5 Performance
196
7.4 Methods for Flexible Content Repository Functions in Hybrid Peer–to–Peer Overlays
201
7.4.1 Reliability
201
7.4.2 Consistency
202
7.4.3 Reconfigurability
203
7.4.4 Scalability
203
7.4.5 Performance
204
7.5 Summary
208
8 Conclusion and Outlook
210
8.1 Conclusion
210
8.2 Future Work
213
Bibliography
217
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