Design and Implementation of a Peer-to-Peer based System to enable the Share Functionality in a Platform-independent Cloud Storage Overlay

Related Topics
design and implementation of a peer-to-peer based system to enable the share functionality in a platform-independent cloud storage overlay
boundary surveying and boundary management issues in nigeria
analysis of spatial distribution of gsm base stations
urban-induced landuse / landcover changes
crime mapping and analysis in kaduna metropolis, kaduna state nigeria
biophysical characteristics and landuse/landcover changes in the upper kubanni river basin, kaduna state, nigeria
spatio-temporal pattern of land values in the zaria urban area, kaduna state, nigeria
cadastral mapping using remote sensing and geographic information system
an assessment of the impact of the growth of zaria on the surrounding vegetation cover
creation of geodatabase and mapping of healthcare facilities
potentials of remote sensing and g.i.s techniques in 3d seismic survey design optimization for oil and gas exploration in the niger delta basin, nigeria
creation of digital cadastre for part of sunshine estate, akure south local government area, ondo state.
topographical survey
application of gis and remote sensing technologies in guaranteeing tenure security for holder farmers in south eastern (geopolitical zone) states of nigeria-an overview
multimedia gis of tourism sites in cross river state

Design and Implementation of a Peer-to-Peer based System to enable the Share Functionality in a Platform-independent Cloud Storage Overlay

By

Author

Presented To

Department of Surveying and Geoinformatics

97 Pages 10,089 Words 2,250 Views PDF Format No. of Chapters: 1 to 6 Chapters

ABSTRACT

Cloud storage services have aroused great interest in modern information technology,

providing a simple way of storing and sharing files. However, they are mostly built on

centralized architectures and hence subject to drawbacks. Peer-to-Peer (P2P) systems are

a good alternative to deal with the limitations of centralized systems in the scope of file

sharing, due to shared usage of distributed resources and higher fault tolerance. Therefore,

this thesis designs, implements, and evaluates a P2P-based file sharing system to be

integrated into PiCsMu, a novel platform-independent cloud storage application. The

proposed system features a modular design which relies on well-defined interfaces, high

security, as well as a P2P storage concept with good performance. Additional features that

try to distinguish this approach from other P2P file sharing systems include an integrated

file search and the possibility to privately share files. The results of a qualitative and

quantitative evaluation show that the proposed system performs well and as designed.

Considering that a download of 750 Megabytes files takes in average 154.65 seconds, the

complexity added by the proposed system (4.21 seconds) is minimal. Yet the system still

leaves aspects to be optimized.

Contents

Abstract i

Zusammenfassung iii

Acknowledgments v

1 Introduction 1

11 Description of Work and Thesis Goals 3

12 Thesis Outline 3

2 Terminology and Related Work 5

21 Terminology 5

22 Cloud Storage Services 6

23 A Brief History of Peer-to-Peer File Sharing 7

231 Napster 8

232 Gnutella 8

233 BitTorrent 9

234 Anonymous P2P and Freenet 11

235 Comparison 12

3 Design 17

31 File Upload and Download Protocol 17

32 Index 18

33 System Architecture 20

331 Application 20

332 Central Server 22

333 Peer-to-Peer Network 23

334 Cloud Services 25

34 Distributed Hash Table 25

341 Storage Concept using a Distributed Hash Table 26

342 Enabling a Content-Based Search 27

35 Privacy and Secure Data Exchange 29

351 Cryptography 30

36 Share Functionality 32

361 Public Sharing 32

362 Share Notification 33

363 Private Sharing 34

4 Implementation 37

41 An Overview of the P2P Code Architecture 37

42 Data Exchange using Beans 38

43 File-Sharing Protocols 38

44 Asynchronous and Non-Blocking Communication 40

441 Interacting with the DHT using Futures 41

442 Asynchronous Callbacks and Event Handling 42

45 Implementing Security Measures 44

46 File Search Functionality 46

461 Keyword Generation 47

462 Fast Similarity Search 48

5 Evaluation 49

51 Testbed and Evaluation Setup 49

511 Test Cases 50

52 Qualitative Evaluation 50

521 Code Coverage using JUnit Tests 50

522 Functional Testing 53

53 Quantitative Evaluation 54

54 Additional Issues and Problems 58

6 Summary and Conclusions 61

Bibliography 69

Abbreviations 71

Glossary 73

List of Figures 75

List of Tables 77

List of Listings 79

A Installation Guidelines 83

B Contents of the CD 85

Chapter 1

Introduction

Modern Information Technology (IT) strives to provide computing as a utility Utility

computing is a concept based on delivering services and resources (eg, processing, stor-

age, software) to end-users while hiding their internal mechanisms The acquisition of

these offerings should be possible at minimal costs, having the advantage of being pur-

chasable from private users to large IT companies As an example, developers can easily

launch new Internet services without the need to primarily invest a large amount of money

in infrastructure Thus, organizations are able to first deploy services and later check if the

demands meet predictions, eg, number of users simultaneously accessing the service [21]

Multiple distributed technologies such as cluster, grid, and cloud computing have emerged

from this paradigm They allow access to large amounts of computing power in a fully

virtualized manner, by aggregating resources and offering a single system view [25]

Cloud computing (or simply cloud) has been one of the most used buzzwords in IT over

recent years The name emerged as a metaphor for the Internet, which has been typically

represented as a cloud symbol in network diagrams [59] The symbol is an abstraction

for the complex underlying mechanisms A variety of cloud providers (ie, companies

offering cloud computing) have been incorporated over the last couple of years, including

big names such as Amazon, Google, and Microsoft They offer cloud services that can

be classified into three types: Infrastructure-as-a-Service (IaaS), Platform-as-a-Service

(PaaS), and Software-as-a-Service (SaaS) [59] Well-known examples of cloud services are,

among others, Amazon Web Services [1], Google Picasa [9], or Microsoft Office 365 [11]

Section 22 introduces cloud services relevant for this thesis In the scope of SaaS, cloud

providers offer applications with a specific purpose and responsibility Consequently, data

that is uploaded to the services is restricted by the corresponding cloud providers’ data

validation process For example, Google Picasa only allows hosting images of a certain

file type, resolution, and size Machado et al [42] investigated on how to bypass the

data validation process of cloud providers to store arbitrary data without restrictions

By applying different encoders (ie, Steganography-related, FileFormatHeader-related,

Appending-related) data is transformed to a form accepted by the cloud provider A

weak data validation process does not recognize this change in data Therefore, it is

possible to upload any kind of data to a cloud service without violating the service-specific

restrictions being noticed by the cloud provider, causing impacts in security, accounting,

and charging

On the basis of the idea presented by Machado et al, its authors created a Platform-

independent Cross Storage System for Multi-Usage (PiCsMu) [15] PiCsMu is a proto-

typical cloud-based overlay (ie, network on top of another network) offering file type

independent cloud storage using file type dependent cloud services By applying encod-

ing, the application can store arbitrary files on any cloud service The way PiCsMu stores

files is divided into three major steps: (1) fragmentation, (2) encoding, and (3) upload

Step (1) splits the file to be uploaded into multiple file parts In the scope of (2), each

file part is encoded specific to the service the file part will be uploaded Finally, step (3)

uploads all encoded file parts to their corresponding cloud service Advantages of this

method are discussed in Section 22; and the individual steps are explained in more detail

in Section 31 In order to retrieve the file, the reversed process is applied PiCsMu itself

does not store data, but index data (ie, index data, this is data about data), which con-

tains information about the upload process, such as (1) number and order of fragmented

file parts, (2) applied encoders, and (3) used cloud services Using the index data, PiC-

sMu is able to retrieve and reconstruct a previously stored file Section 32 describes how

the index data is composed The denotation of PiCsMu as an overlay is based upon the

characteristics that it runs on top of multiple cloud services, using indexes to manage the

files distributed across them

Since the file parts are stored in public available services, any authorized person can access

and download them Hence, by sharing index data of a file with another PiCsMu user,

he or she can obtain all necessary file parts from the corresponding cloud services and

reconstruct the file using index data information As a client-server (C/S) application,

PiCsMu offers a centralized way of sharing files However, having one central authority

bears drawbacks in applying file sharing High network traffic from many concurrent

users may rapidly lead to congestion at the server, causing a temporal denial of service

or complete breakdown Further, the identity of the users (ie, Internet Protocol (IP)

address) is known to the server and can be required by governmental authorities for

prosecution in case of sharing copyrighted or sensitive files Having said this, it is also

easy for an authority to shut down the entire system by disabling the central server

Peer-to-Peer (P2P) systems have become popular on the Internet, especially in the field of

file sharing and media streaming Steinmetz et al [54] provide the following definition: “A

Peer-to-Peer system is a self-organizing system of equal, autonomous entities (peers) which

aims for the shared usage of distributed resources in a networked environment avoiding

central services” The increasing availability of high-speed broadband connections made

the concept of globally applicable P2P systems feasible Average users have the computa-

tional capacity and resources to act as as server and client simultaneously (ie, definition

of a peer), providing and consuming data P2P systems are designed to overcome the

limitations and drawbacks of classical C/S systems They are (1) extensible (easy to add

new resources), (2) more fault tolerant, (3) scalable (system can grow without loss in

performance), and (4) resistant to lawsuits Hence, this thesis investigates, implements,

evaluates, and discusses the design of a P2P-based system to enable a distributed share

functionality in PiCsMu to overcome its current architectural limitations

11 Description of Work and Thesis Goals

The objective of this thesis is to design, implement, and evaluate a P2P-based system

to be integrated into PiCsMu to extend and enhance current functionality This primar-

ily includes the introduction of a distributed and decentralized file sharing and storing

mechanism Since PiCsMu already exists as a prototypical implementation, the system

architecture and code design is analyzed in order to integrate new functions in the best

possible way, minimizing changes to the original PiCsMu implementation Furthermore,

an investigation and comparison of related work in the field of cloud storage services is

done to see how PiCsMu differs in features and how the work of this thesis can make a

contribution The proposed P2P solution is compared side-by-side with well-known P2P

file-sharing systems in order to analyze advantages and drawbacks The observation of

the current implementation of PiCsMu, together with the analysis of related work, result

in a design solution for the new PiCsMu with a P2P extension The design is intended

to be modular, in order to make future adaptions (eg, new features, different P2P ar-

chitecture) possible with minimum effort In addition, design decisions are based on how

to make best use of the functionality that PiCsMu already offers The implementation

realizes all aspects of the design and is done in the Java programming language In the

scope of evaluation, the proposed solution is evaluated to survey the design’s validity and

feasibility The evaluation process comprises of defining different scenarios in which the

system’s functionality and performance is measured, and the results obtained are dis-

cussed Finally, the end-to-end work is analyzed and open issues as well as future work

are presented

12 Thesis Outline

The remainder of this thesis is structured as follows: Chapter 2 presents the terminology

and the related work in the area of cloud services and P2P file-sharing systems Chapter 3

presents the design of the proposed system architecture and explains the system compo-

nents thoroughly Chapter 4 focuses on the technical part of the thesis and explains how

the design decisions are implemented into PiCsMu Chapter 5 presents and discusses

results obtained from the evaluation Finally, Chapter 6 summarizes and concludes what

was achieved and presents future work

97 Pages 10,089 Words 2,250 Views PDF Format No. of Chapters: 1 to 6 Chapters

Copy/document the link below if you want to visit this page next time

FOR ENQUIRY
support@e-projecttopics.com
09019904113