DOCSLIB.ORG

DECENTRALIZED FILE SHARING on MOBILE DEVICES Master’S Thesis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
DECENTRALIZED FILE SHARING on MOBILE DEVICES Master’S Thesis OLLI-PEKKA HEINISUO DECENTRALIZED FILE SHARING ON MOBILE DEVICES Master’s thesis Examiners: Asst. Prof. Davide Taibi and Postdoctoral Researcher Valentina Lenarduzzi The examiners and topic of the the- sis were approved on 29 August 2018 i ABSTRACT OLLI-PEKKA HEINISUO: Decentralized File Sharing on Mobile Devices Tampere University of Technology Master of Science Thesis, 52 pages November 2018 Master’s Degree Programme in Information Technology Major: Pervasive Systems Examiners: Asst. Prof. Davide Taibi and Postdoctoral Researcher Valentina Lenarduzzi Keywords: decentralization, mobile application, p2p, file sharing Most applications and services rely on central authorities. This introduces a single point of failure to the system. The central authority must be trusted to have data stored by the application available at any given time. More importantly, the privacy of the user depends on the service provider capability to keep the data safe. To remove the central authority a decentralized system is needed. Due to the rapid growth of mobile device usage, the availability of decentralization must not be limited only to desktop computers. This thesis examined the possibility to use mobile devices as a decentralized file sharing platform without any central authorities. This was done by implementing a peer-to-peer file sharing mobile application. InterPlanetary File System was selected as the peer-to-peer network. To evaluate the validity of the approach, network usage and power consumption of multiple different devices was measured while the application was running. The results indicate that mobile devices can be used to implement a worldwide distributed file sharing network. However, the file sharing application generated large amounts of network traffic even when no files were shared. This was caused by the chattiness ofthe protocol of the underlying peer-to-peer network. Consequently, constant network traffic prevented the mobile devices from entering to deep sleep mode. Due to this the battery life of the devices was greatly degraded. Further measurements are needed when the InterPlanetary File System reference implementation is more mature. A paper about the results of this thesis has been submitted to the Seventh IEEE International Conference on Mobile Cloud Computing [36]. ii TIIVISTELMÄ OLLI-PEKKA HEINISUO: Hajautettu tiedostojenjako mobiililaitteilla Tampereen teknillinen yliopisto Diplomityö, 52 sivua Marraskuu 2018 Tietotekniikan DI-tutkinto-ohjelma Pääaine: Pervasive Systems Tarkastajat: apulaisprofessori Davide Taibi ja tutkijatohtori Valentina Lenarduzzi Avainsanat: hajautettu järjestelmä, mobiilisovellus, vertaisverkko, tiedostonjako Useimmat sovellukset ja palvelut ovat riippuvaisia keskitetyistä järjestelmistä. Sovellus- ten käyttäjien on luotettava siihen, että palvelut ovat saatavilla milloin tahansa. Tämän lisäksi käyttäjien tietojen turvallisuus on kokonaan palveluntarjoajan käsissä. Tarve kes- kitetyille palveluille voidaan kiertää täysin hajautetuilla järjestelmillä. Mobiililaitteiden käytön suuren kasvun vuoksi tällaista hajautettua järjestelmää ei voida rajoittaa pelkästään työpöytäkäyttöön. Tässä työssä tutkittiin, onko mobiililaitteita mahdollista käyttää täysin hajautetun tiedos- tojenjakopalvelun alustana. Tätä varten työssä toteutettiin vertaisverkkoon perustuva tie- dostojenjakosovellus mobiililaitteille. Vertaisverkoksi valittiin InterPlanetary File System. Toteutuksen käyttökelpoisuuden arvioimiseksi usean eri mobiililaitteen virrankulutus sekä verkon käyttö mitattiin sovelluksen ollessa päällä. Tulosten perusteella mobiililaitteita voidaan käyttää alustana maailmanlaajuisen hajautetun tiedostonjakoverkon toteuttamiseen. Tästä huolimatta on huomioitava, että kehitetty sovel- lus käytti verkkoa todella paljon. Tämä johtui käytetyn vertaisverkon protokollasta, joka vaihtoi tietoa muun verkon kanssa jatkuvasti. Jatkuvasta verkkoliikenteestä johtuen mitatut laitteet eivät koskaan päässeet lepotilaan, mikä puolestaan johti suureen virrankulutukseen. Tehdyt mittaukset tulisi toistaa, kun käytetyn vertaisverkon referenssitoteutusta on opti- moitu ja kehitetty edelleen. Työn tuloksista on lähetetty tieteellinen artikkeli Seventh IEEE International Conference on Mobile Cloud Computing –konferenssiin [36]. iii PREFACE This thesis is the end result of working and studying at the same time for the past seven and a half years. It was not easy to figure out a good topic but I am happy that I ended upwith this one. While this thesis is my personal work and it was done without external support, I am grateful for the wide industry experience I have gained at the companies at which I have worked during the past years. I would like to thank Assistant Professor Davide Taibi for the feedback during the writing process of this thesis and for the opportunity to summarize the work into a scientific paper. I would also like to express my gratitude to my family and friends. Special thanks to my girlfriend for supporting me during the thesis work. In Tampere, Finland, on 15th November 2018 Olli-Pekka Heinisuo iv CONTENTS 1. INTRODUCTION ................................................................................................. 1 2. THEORETICAL BACKGROUND........................................................................ 3 2.1 Network Architectures ................................................................................ 3 2.2 Peer-to-Peer Overlay Networks ................................................................... 5 2.3 Peer-to-Peer File Sharing ............................................................................ 7 2.4 Trust, Security and Privacy in Peer-to-Peer Networks................................ 10 2.5 Peer-to-Peer in Mobile Environments......................................................... 11 2.6 Modern Peer-to-Peer File Sharing .............................................................. 12 2.7 InterPlanetary File System.......................................................................... 14 2.8 Related Work............................................................................................... 17 3. FILE SHARING MOBILE APPLICATION ......................................................... 21 3.1 Use Cases.................................................................................................... 21 3.1.1 Background Execution.................................................................. 21 3.1.2 Managing Node Settings............................................................... 21 3.1.3 Sharing Files ................................................................................. 22 3.1.4 Retrieving Files............................................................................. 22 3.1.5 Managing Files ............................................................................. 22 3.1.6 Viewing Node Information ........................................................... 22 3.2 System Requirements.................................................................................. 22 3.3 Existing IPFS Mobile Applications ............................................................ 23 3.4 Platform Selection....................................................................................... 23 3.5 Sailfish OS .................................................................................................. 24 3.6 Risks and Challenges .................................................................................. 25 4. IMPLEMENTATION ............................................................................................ 26 4.1 Overview of the Architecture...................................................................... 26 4.2 Libipfs – Wrapper Library for go-ipfs ........................................................ 27 4.2.1 Cross-compilation for Sailfish OS Devices .................................. 28 4.2.2 Continuous Integration ................................................................. 28 4.3 Asterism – IPFS Mobile Client Application............................................... 31 5. SYSTEM EVALUATION AND DISCUSSION.................................................... 35 5.1 Measurements ............................................................................................. 35 5.1.1 Power Consumption...................................................................... 37 5.1.2 Network Usage.............................................................................. 41 5.2 Functionality ............................................................................................... 43 5.3 Discussion................................................................................................... 44 6. CONCLUSIONS.................................................................................................... 46 REFERENCES .............................................................................................................. 48 v LIST OF SYMBOLS AND ABBREVIATIONS ARM an processor architecture ARPANET Advanced Research Projects Agency Network, the early Internet CI Continuous Integration CPU Central Processing Unit DAG Directed Acyclic Graph DHT Distributed Hash Table GUI Graphical User Interface HTTP Hypertext Transfer Protocol ID Identifier IPFS InterPlanetary File System IPLD InterPlanetary Linked Data IPNS InterPlanetary Naming System MFS Mutable File System NAT Network Access Translation OS Operating System p2p peer-to-peer QML Qt Modeling Language Qt cross-platform application development framework
Load more

Recommended publications
  • What Is Peer-To-Peer File Transfer? Bandwidth It Can Use
    sharing, with no cap on the amount of commonly used to trade copyrighted music What is Peer-to-Peer file transfer? bandwidth it can use. Thus, a single NSF PC and software. connected to NSF’s LAN with a standard The Recording Industry Association of A peer-to-peer, or “P2P,” file transfer 100Mbps network card could, with KaZaA’s America tracks users of this software and has service allows the user to share computer files default settings, conceivably saturate NSF’s begun initiating lawsuits against individuals through the Internet. Examples of P2P T3 (45Mbps) internet connection. who use P2P systems to steal copyrighted services include KaZaA, Grokster, Gnutella, The KaZaA software assesses the quality of material or to provide copyrighted software to Morpheus, and BearShare. the PC’s internet connection and designates others to download freely. These services are set up to allow users to computers with high-speed connections as search for and download files to their “Supernodes,” meaning that they provide a How does use of these services computers, and to enable users to make files hub between various users, a source of available for others to download from their information about files available on other create security issues at NSF? computers. users’ PCs. This uses much more of the When configuring these services, it is computer’s resources, including bandwidth possible to designate as “shared” not only the and processing capability. How do these services function? one folder KaZaA sets up by default, but also The free version of KaZaA is supported by the entire contents of the user’s computer as Peer to peer file transfer services are highly advertising, which appears on the user well as any NSF network drives to which the decentralized, creating a network of linked interface of the program and also causes pop- user has access, to be searchable and users.
    [Show full text]
  • The Effects of Digital Music Distribution" (2012)
    Southern Illinois University Carbondale OpenSIUC Research Papers Graduate School Spring 4-5-2012 The ffecE ts of Digital Music Distribution Rama A. Dechsakda [email protected] Follow this and additional works at: http://opensiuc.lib.siu.edu/gs_rp The er search paper was a study of how digital music distribution has affected the music industry by researching different views and aspects. I believe this topic was vital to research because it give us insight on were the music industry is headed in the future. Two main research questions proposed were; “How is digital music distribution affecting the music industry?” and “In what way does the piracy industry affect the digital music industry?” The methodology used for this research was performing case studies, researching prospective and retrospective data, and analyzing sales figures and graphs. Case studies were performed on one independent artist and two major artists whom changed the digital music industry in different ways. Another pair of case studies were performed on an independent label and a major label on how changes of the digital music industry effected their business model and how piracy effected those new business models as well. I analyzed sales figures and graphs of digital music sales and physical sales to show the differences in the formats. I researched prospective data on how consumers adjusted to the digital music advancements and how piracy industry has affected them. Last I concluded all the data found during this research to show that digital music distribution is growing and could possibly be the dominant format for obtaining music, and the battle with piracy will be an ongoing process that will be hard to end anytime soon.
    [Show full text]
  • The Edonkey File-Sharing Network
    The eDonkey File-Sharing Network Oliver Heckmann, Axel Bock, Andreas Mauthe, Ralf Steinmetz Multimedia Kommunikation (KOM) Technische Universitat¨ Darmstadt Merckstr. 25, 64293 Darmstadt (heckmann, bock, mauthe, steinmetz)@kom.tu-darmstadt.de Abstract: The eDonkey 2000 file-sharing network is one of the most successful peer- to-peer file-sharing applications, especially in Germany. The network itself is a hybrid peer-to-peer network with client applications running on the end-system that are con- nected to a distributed network of dedicated servers. In this paper we describe the eDonkey protocol and measurement results on network/transport layer and application layer that were made with the client software and with an open-source eDonkey server we extended for these measurements. 1 Motivation and Introduction Most of the traffic in the network of access and backbone Internet service providers (ISPs) is generated by peer-to-peer (P2P) file-sharing applications [San03]. These applications are typically bandwidth greedy and generate more long-lived TCP flows than the WWW traffic that was dominating the Internet traffic before the P2P applications. To understand the influence of these applications and the characteristics of the traffic they produce and their impact on network design, capacity expansion, traffic engineering and shaping, it is important to empirically analyse the dominant file-sharing applications. The eDonkey file-sharing protocol is one of these file-sharing protocols. It is imple- mented by the original eDonkey2000 client [eDonkey] and additionally by some open- source clients like mldonkey [mlDonkey] and eMule [eMule]. According to [San03] it is with 52% of the generated file-sharing traffic the most successful P2P file-sharing net- work in Germany, even more successful than the FastTrack protocol used by the P2P client KaZaa [KaZaa] that comes to 44% of the traffic.
    [Show full text]
  • IPFS and Friends: a Qualitative Comparison of Next Generation Peer-To-Peer Data Networks Erik Daniel and Florian Tschorsch
    1 IPFS and Friends: A Qualitative Comparison of Next Generation Peer-to-Peer Data Networks Erik Daniel and Florian Tschorsch Abstract—Decentralized, distributed storage offers a way to types of files [1]. Napster and Gnutella marked the beginning reduce the impact of data silos as often fostered by centralized and were followed by many other P2P networks focusing on cloud storage. While the intentions of this trend are not new, the specialized application areas or novel network structures. For topic gained traction due to technological advancements, most notably blockchain networks. As a consequence, we observe that example, Freenet [2] realizes anonymous storage and retrieval. a new generation of peer-to-peer data networks emerges. In this Chord [3], CAN [4], and Pastry [5] provide protocols to survey paper, we therefore provide a technical overview of the maintain a structured overlay network topology. In particular, next generation data networks. We use select data networks to BitTorrent [6] received a lot of attention from both users and introduce general concepts and to emphasize new developments. the research community. BitTorrent introduced an incentive Specifically, we provide a deeper outline of the Interplanetary File System and a general overview of Swarm, the Hypercore Pro- mechanism to achieve Pareto efficiency, trying to improve tocol, SAFE, Storj, and Arweave. We identify common building network utilization achieving a higher level of robustness. We blocks and provide a qualitative comparison. From the overview, consider networks such as Napster, Gnutella, Freenet, BitTor- we derive future challenges and research goals concerning data rent, and many more as first generation P2P data networks, networks.
    [Show full text]
  • A Fog Storage Software Architecture for the Internet of Things Bastien Confais, Adrien Lebre, Benoît Parrein
    A Fog storage software architecture for the Internet of Things Bastien Confais, Adrien Lebre, Benoît Parrein To cite this version: Bastien Confais, Adrien Lebre, Benoît Parrein. A Fog storage software architecture for the Internet of Things. Advances in Edge Computing: Massive Parallel Processing and Applications, IOS Press, pp.61-105, 2020, Advances in Parallel Computing, 978-1-64368-062-0. 10.3233/APC200004. hal- 02496105 HAL Id: hal-02496105 https://hal.archives-ouvertes.fr/hal-02496105 Submitted on 2 Mar 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. November 2019 A Fog storage software architecture for the Internet of Things Bastien CONFAIS a Adrien LEBRE b and Benoˆıt PARREIN c;1 a CNRS, LS2N, Polytech Nantes, rue Christian Pauc, Nantes, France b Institut Mines Telecom Atlantique, LS2N/Inria, 4 Rue Alfred Kastler, Nantes, France c Universite´ de Nantes, LS2N, Polytech Nantes, Nantes, France Abstract. The last prevision of the european Think Tank IDATE Digiworld esti- mates to 35 billion of connected devices in 2030 over the world just for the con- sumer market. This deep wave will be accompanied by a deluge of data, applica- tions and services.
    [Show full text]
  • Privacy Enhancing Technologies 2003 an Analysis of Gnunet And
    Privacy Enhancing Technologies 2003 An Analysis of GNUnet and the Implications for Anonymous, Censorship-Resistant Networks Dennis Kügler Federal Office for Information Security, Germany [email protected] 1 Anonymous, Censorship-Resistant Networks • Anonymous Peer-to-Peer Networks – Gnutella • Searching is relatively anonymous • Downloading is not anonymous • Censorship-Resistant Networks – Eternity Service • Distributed storage medium • Attack resistant • Anonymous, Censorship-Resistant Networks – Freenet – GNUnet 2 GNUnet: Obfuscated, Distributed Filesystem Content Hash Key: [H(B),H(E (B))] • H(B) – Content encryption: H(B) – Unambiguous filename: H(E (B)) H(B) • Content replication – Caching while delivering – Based on unambiguous filename • Searchability – Keywords 3 GNUnet: Peer-to-Peer MIX Network • Initiating node – Downloads content • Supplying nodes – Store content unencrypted • Intermediary nodes – Forward and cache encrypted content – Plausible deniability due to encryption • Economic model – Based on credit Query A Priority=20 B – Charge for queries c =c -20 B B - – Pay for responses 4 GNUnet Encoding • DBlocks DBlock DBlock ... DBlock – 1KB of the content – Content hash encrypted • IBlocks IBlock ... IBlock – CHKs of 25 DBlocks – Organized as tree – Content hash encrypted IBlock • RBlock – Description of the content – CHK of the root IBlock RBlock – Keyword encrypted 5 The Attacker Model • Attacker – Controls malicious nodes that behave correctly – Prepares dictionary of interesting keywords – Observes queries and
    [Show full text]
  • Piratez Are Just Disgruntled Consumers Reach Global Theaters That They Overlap the Domestic USA Blu-Ray Release
    Moviegoers - or perhaps more accurately, lovers of cinema - are frustrated. Their frustrations begin with the discrepancies in film release strategies and timing. For example, audiences that saw Quentin Tarantino’s1 2 Django Unchained in the United States enjoyed its opening on Christmas day 2012; however, in Europe and other markets, viewers could not pay to see the movie until after the 17th of January 2013. Three weeks may not seem like a lot, but some movies can take months to reach an international audience. Some take so long to Piratez Are Just Disgruntled Consumers reach global theaters that they overlap the domestic USA Blu-Ray release. This delay can seem like an eternity for ultiscreen is at the top of the entertainment a desperate fan. This frustrated enthusiasm, combined industry’s agenda for delivering digital video. This with a lack of timely availability, leads to the feeling of M is discussed in the context of four main screens: being treated as a second class citizen - and may lead TVs, PCs, tablets and mobile phones. The premise being the over-anxious fan to engage in piracy. that multiscreen enables portability, usability and flexibility for consumers. But, there is a fifth screen which There has been some evolution in this practice, with is often overlooked – the cornerstone of the certain films being released simultaneously to a domestic and global audience. For example, Avatar3 was released entertainment industry - cinema. This digital video th th ecosystem is not complete without including cinema, and in theaters on the 10 and 17 of December in most it certainly should be part of the multiscreen discussion.
    [Show full text]
  • [Hal-00744922, V1] Improving Content Availability in the I2P Anonymous
    Improving Content Availability in the I2P Anonymous File-Sharing Environment Juan Pablo Timpanaro, Isabelle Chrisment*, Olivier Festor INRIA Nancy-Grand Est, France *LORIA - ESIAL, Universit´ede Lorraine Email: fjuanpablo.timpanaro, [email protected] Email: [email protected] Abstract. Anonymous communication has gained more and more inter- est from Internet users as privacy and anonymity problems have emerged. Dedicated anonymous networks such as Freenet and I2P allow anony- mous file-sharing among users. However, one major problem with anony- mous file-sharing networks is that the available content is highly reduced, mostly with outdated files, and non-anonymous networks, such as the BitTorrent network, are still the major source of content: we show that in a 30-days period, 21648 new torrents were introduced in the BitTor- rent community, whilst only 236 were introduced in the anonymous I2P network, for four different categories of content. Therefore, how can a user of these anonymous networks access this varied and non-anonymous content without compromising its anonymity? In this paper, we improve content availability in an anonymous environment by proposing the first internetwork model allowing anonymous users to access and share content in large public communities while remaining anonymous. We show that our approach can efficiently interconnect I2P users and public BitTorrent swarms without affecting their anonymity nor their performance. Our model is fully implemented and freely usable. 1 Introduction Peer-to-peer file-sharing has always been one of the major sources of the Internet hal-00744922, version 1 - 24 Oct 2012 traffic, since its early beginnings in 2000. It has been moving from semi-central approaches (eDonkey2000, for example), to semi-decentralized approaches (Kazaa, for instance) to fully decentralized file-sharing architectures (like the KAD net- work).
    [Show full text]
  • Downloading Copyrighted Materials
    What you need to know before... Downloading Copyrighted Materials Including movies, TV shows, music, digital books, software and interactive games The Facts and Consequences Who monitors peer-to-peer file sharing? What are the consequences at UAF The Motion Picture Association of America for violators of this policy? (MPAA), Home Box Office, and other copyright Student Services at UAF takes the following holders monitor file-sharing on the Internet minimum actions when the policy is violated: for the illegal distribution of their copyrighted 1st Offense: contents. Once identified they issue DMCA Loss of Internet access until issue is resolved. (Digital Millennium Copyright Act) take-down 2nd Offense: notices to the ISP (Internet Service Provider), in Loss of Internet access pending which the University of Alaska is considered as resolution and a $100 fee assessment. one, requesting the infringement be stopped. If 3rd Offense: not stopped, lawsuit against the user is possible. Loss of Internet access pending resolution and a $250 fee assessment. What is UAF’s responsibility? 4th, 5th, 6th Offense: Under the Digital Millennium Copyright Act and Loss of Internet access pending resolution and Higher Education Opportunity Act, university a $500 fee assessment. administrators are obligated to track these infractions and preserve relevent logs in your What are the Federal consequences student record. This means that if your case goes for violators? to court, your record may be subpoenaed as The MPAA, HBO and similar organizations are evidence. Since illegal file sharing also drains becoming more and more aggressive in finding bandwidth, costing schools money and slowing and prosecuting alleged offenders in criminal Internet connections, for students trying to use court.
    [Show full text]
  • The Robustness of Content-Based Search in Hierarchical Peer to Peer Networks
    The Robustness of Content-Based Search in Hierarchical Peer to Peer Networks ∗ M. Elena Renda Jamie Callan I.S.T.I. – C.N.R. Language Technologies Institute and School of Computer Science Scuola Superiore Sant’Anna Carnegie Mellon University I-56100 Pisa, Italy Pittsburgh, PA 15213, US [email protected] [email protected] ABSTRACT Keywords Hierarchical peer to peer networks with multiple directory services Peer to Peer, Hierarchical, Search, Retrieval, Content-based, Ro- are an important architecture for large-scale file sharing due to their bustness effectiveness and efficiency. Recent research argues that they are also an effective method of providing large-scale content-based federated search of text-based digital libraries. In both cases the 1. INTRODUCTION directory services are critical resources that are subject to attack Peer to peer (P2P) networks have emerged in recent years as a or failure, but the latter architecture may be particularly vulnera- popular method of sharing information, primarily popular music, ble because content is less likely to be replicated throughout the movies, and software, among large numbers of networked com- network. puters. Computers (‘nodes’) in P2P networks can be information This paper studies the robustness, effectiveness and efficiency providers and information consumers, and may provide network of content-based federated search in hierarchical peer to peer net- services such as message routing and regional directory services. works when directory services fail unexpectedly. Several recovery A single node may play several roles at once, for example, posting methods are studied using simulations with varying failure rates. queries, sharing files, and relaying messages.
    [Show full text]
  • Will Sci-Hub Kill the Open Access Citation Advantage and (At Least for Now) Save Toll Access Journals?
    Will Sci-Hub Kill the Open Access Citation Advantage and (at least for now) Save Toll Access Journals? David W. Lewis October 2016 © 2016 David W. Lewis. This work is licensed under a Creative Commons Attribution 4.0 International license. Introduction It is a generally accepted fact that open access journal articles enjoy a citation advantage.1 This citation advantage results from the fact that open access journal articles are available to everyone in the word with an Internet collection. Thus, anyone with an interest in the work can find it and use it easily with no out-of-pocket cost. This use leads to citations. Articles in toll access journals on the other hand, are locked behind paywalls and are only available to those associated with institutions who can afford the subscription costs, or who are willing and able to purchase individual articles for $30 or more. There has always been some slippage in the toll access journal system because of informal sharing of articles. Authors will usually send copies of their work to those who ask and sometime post them on their websites even when this is not allowable under publisher’s agreements. Stevan Harnad and his colleagues proposed making this type of author sharing a standard semi-automated feature for closed articles in institutional repositories.2 The hashtag #ICanHazPDF can be used to broadcast a request for an article that an individual does not have access to.3 Increasingly, toll access articles are required by funder mandates to be made publically available, though usually after an embargo period.
    [Show full text]
  • Scalable Supernode Selection in Peer-To-Peer Overlay Networks∗
    Scalable Supernode Selection in Peer-to-Peer Overlay Networks∗ Virginia Lo, Dayi Zhou, Yuhong Liu, Chris GauthierDickey, and Jun Li {lo|dayizhou|liuyh|chrisg|lijun} @cs.uoregon.edu Network Research Group – University of Oregon Abstract ically fulfill additional requirements such as load bal- ance, resources, access, and fault tolerance. We define a problem called the supernode selection The supernode selection problem is highly challeng- problem which has emerged across a variety of peer-to- ing because in the peer-to-peer environment, a large peer applications. Supernode selection involves selec- number of supernodes must be selected from a huge tion of a subset of the peers to serve a special role. The and dynamically changing network in which neither the supernodes must be well-dispersed throughout the peer- node characteristics nor the network topology are known to-peer overlay network, and must fulfill additional re- a priori. Thus, simple strategies such as random selec- quirements such as load balance, resource needs, adapt- tion don’t work. Supernode selection is more complex ability to churn, and heterogeneity. While similar to than classic dominating set and p-centers from graph dominating set and p-centers problems, the supernode theory, known to be NP-hard problems, because it must selection problem must meet the additional challenge respond to dynamic joins and leaves (churn), operate of operating within a huge, unknown and dynamically among potentially malicious nodes, and function in an changing network. We describe three generic super- environment that is highly heterogeneous. node selection protocols we have developed for peer-to- Supernode selection shows up in many peer-to-peer peer environments: a label-based scheme for structured and networking applications.
    [Show full text]