UP2P

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U-P2P

• A Peer-to-peer System for Description and
  Discovery of Resource-sharing Communities
• Aloke Mukherjee, Carleton University
• August 28, 2003

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Peer-to-peer File-sharing

• Exploit storage capability of the edge
• Balance load
• Robustness to failure
• Weaknesses Search and Communities

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Search Problem

• Lack of structured metadata
• Filenames, Keyword matching
• Opaque identifiers
• Support for popular formats
• Ignoring structured metadata
• Implicit indicators
• Collaborative filtering

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State of the Art Search
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Community Problem

• Not simple to create a community for sharing a
  new file format
• Current state
• Different protocols/apps (gnutella, fasttrack,
  jxtasearch)
• Inadequate metadata (filename matching, limited
  schemas)
• Ad-hoc attempts aimed at specific domains
• Scattered and isolated there is no easy way to
  discover communities

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State of the Art Communities
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Improving Search

• Standard metadata layer
• Explicit structured metadata
• All resources are XML files
• XML Schema used to describe format (e.g. MP3,
  design pattern)

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Schema instantiates resource

typestring typestring typestring typestring typestring typeanyURI

singleton
gang of four when
creating a new class ensure
a class only has make the
class itself responsible
http//example.com/singleton.jpg
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Automated interface generation
xslt
instantiates
xslt
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Community Creation and DiscoveryWhat is a
Community?

• Concrete object with defined tuple of attributes
• Simplest form (format, protocol, )
• Known examples
• (mp3, napster) (video, kazaa)
• Examples that dont exist
• (design patterns, gnutella) (p2p papers,
  jxtasearch)
• Tuple is specified as a XML file

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Simplifying Community Creation
designpatterns
designpattern.xsd
gnutella designpatt
ern.stylesheet

• User-designed communities
• Compose schema to describe format
• Compose community XML file

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Community as class

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Metaclass analogy

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Community discovery is File discovery

• MP3 community shares MP3 files
• Community community shares communities

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Simplifying Community Discovery

• A Community for Communities The Root Community
• Communities are files shared in a real community
• Root Community includes schema for communities
• (format, protocol) (community, centralized db)

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Schema for Communities

name"name" type"xsdstring"/ name"protocol" type"protocolTypes"/



root community
community.xsd
central-db
community.stylesheet y
The Root Community
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What is U-P2P?

• A framework that breathes life into these ideas
• Explicit metadata search and creation for every
  Community
• Creation of Community tuples
• (format, protocol etc)
• Discovery of Community tuples

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Design
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Technologies

• Java
• Tomcat Servlet Container
• Java Server Pages (JSP) Servlets
• XSLT (transforms), XPath (queries)
• Java components for XSLT, XPath (Xerces, Xalan)
• eXist XML Database
• Log4j (logging infrastructure), JUnit (unit
  testing)

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Evaluation and Validation Areas of Interest

• Publish and Search times as Community size
  increases
• Breaking down Publish and Search operations
• Community effect
• Multiple central servers

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Publish
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Search
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Community Effect
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Multiple Central Servers
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Publish with Multiple Servers
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Vs. Without Multiple Central Servers
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Contributions

• Standard Metadata Layer
• All communities include support for explicit
  metadata search and creation
• User-designed Communities
• Users can easily share new formats with full
  support for metadata
• Community for Communities
• Prevents fragmented, isolated communities by
  providing metadata about communities and a
  standard method for discovering them
• Performance and Scalability Gains
• Communities can improve performance and
  scalability vs. systems where resources are
  undifferentiated

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Future Work

• Performance improvements
• Protocol independence (adapters for Gnutella,
  Freenet, etc.)
• Community-aware Gnutella routing
• More Community parameters (security,
  authentication, etc.)

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Future Work continued

• Trust metrics (to differentiate between
  communities, metadata quality)
• Community evolution
• Inheritance and multiple inheritance for
  Communities

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U-P2P Publications

• A. Mukherjee, B. Esfandiari, N. Arthorne, U-P2P
  A Peer-to-peer System for Description and
  Discovery of Resource-sharing Communities, ICDCS
  Workshops 2002 701-705, July 2002.
• Neal Arthorne, Babak Esfandiari and Aloke
  Mukherjee, "U-P2P A Peer-to-peer Framework for
  Universal Resource Sharing and Discovery,
  Proceedings of Freenix track of Usenix 2003,
  29-38, June 2003.
• http//u-p2p.sourceforge.net

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Backup slides
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WebAdapter User Interaction Model
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Repository Design
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Repository Design Resource IDs
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Repository Design XML Database

• Requirements
• Flexibility to store wide variety of formats
• Handle powerful queries over all metadata
• XML Database better suited than RDBMS
• Difficult to map fields to rows and columns
• Chose eXist XML database
• Open source
• Written in Java
• Support for XMLDB API

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Network Adapter Design

• Abstract interface to Peer-to-peer Network
• Routing search requests, handling results, handle
  incoming search requests, etc.
• Only implemented Hybrid model (Napster model)
• All peers can act as client and/or server

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Network Adapter Protocol
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Evaluation and Validation Challenges

• Finding large XML collections
• Berkeley Drosophila Genome Project genome
  annotations
• Other sources DBLP (CS papers), EDGAR (SEC
  filings), GeneOntology (gene-related concepts)
• Transforming DTDs to XML Schema (DTDXS package)
• Automation
• XML-RPC interface for publish and search

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Publish Breakdown of Operations
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Publish Client Timings
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Publish Server Timings
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Network Adapter Protocol
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Search Breakdown of Operations
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Search Total vs. Server Timings