P2PediaA Distributed Wiki
Network Management and Artificial Intelligence Laboratory
Carleton University
Presented by: Alexander CraigMay 9th, 2011
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Overview
What is a Wiki? Distributed vs. Centralized Wikis Article Versioning Model What is P2Pedia? Versioning Path Queries and Wiki Links
Trust Indicators
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Distributed vs. Centralized Wikis
Traditional wiki systems, such as Wikipedia, use a centralized architecture where all content is stored on a central server.
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Distributed vs. Centralized Wikis
In a distributed wiki system, every user of the system acts as a host, and shares a portion of the wiki data set.
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Advantages of Distributed Wikis
Reliability - No centralized point of failure Scalability - Distributed bandwidth usage
and costs No centralized authority to censor content Offline operation – Users can retain read
and edit access to all locally stored data even in the case of a network failure
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Versioning Model In a distributed system, articles may be
modified concurrently by separate authors on separate nodes.
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Distributed Wikis – Existing Work
Existing work largely aims to present a logically centralized service over a distributed architecture.
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Versioning Model
Distributed modifications result in a tree of article versions, rather than a linear sequence
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Versioning Model: Future Work
P2Pedia also aims to support user assisted merging of articles. In this case, a lattice of article versions may be formed.
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Versioning Model This distributed versioning model reflects
the underlying peer to peer infrastructure of the system, and may be better suited to some domains (ex: teaching materials).
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What is P2Pedia? A distributed wiki system implemented
using the community customization options provided by the Universal Peer to Peer framework
Articles are stored in an XML format, and use the Creole wiki markup open standard
CREOLE – A common wiki markup
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Versioning Queries Complex queries can be performed on the
version graph using the provided graph query functionality of U-P2P.
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Wiki Links Because no authoritative version of an
article exists, wiki links are implemented as a search for all descendents.
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Trust Indicators If article revisions are not merged into a
single version, how should a user select which version of an article to view?
U-P2P provides a number of resource trust indicators alongside search results to provide users with additional information.
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Trust Indicators: Document Popularity
Document popularity = Number of hosts serving the document
Ex: Document Popularity of “A” = 3
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Trust Indicators: Network Distance
Network Distance = Number of intermediate network hops between querying node and host
Ex: Average Network Distance of “A” = 0.5
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Trust Indicators: Peer Popularity
Peer popularity = Number of incoming peer connections to a specified host
Ex: Peer Popularity = 2(Assuming queried connection is outgoing)
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Trust Indicators: Similarity
Similarity = (Number of hosted articles in common) / (Total number of hosted articles)
Similarity = Size({A}) / Size({A, B, C}) = 1/3
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Conclusion P2Pedia expands on existing work by
supporting a collaboration model which supports the diversification of content.
Versioning is realized using document links which are queried through the distributed graph query capabilities of U-P2P.
General trust indicators are introduced to allow users to evaluate the quality of content.
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http://www.nmai.ca/research-projects/universal-peer-to-peer-home
P2Pedia Live Demo:http://inm-04.sce.carleton.ca:8080/up2p/
Questions?
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References
[1] “Wikipedia,” http://www.wikipedia.org/ Accessed May 4th, 2011.
[2] “Wiktionary,” http://www.wiktionary.org/ Accessed May 5th, 2011.
[3] “Lyric Wiki,” http://lyrics.wikia.com/ Accessed May 5th, 2011.
[4] “UniWiki,” http://sourceforge.net/projects/uniwiki/ Accessed May 5th, 2011.
[5] “Wooki,” http://wooki.sourceforge.net/ Accessed May 5th, 2011.
[6] “WikiCreole,” http://www.wikicreole.org/ Accessed May 5th, 2011.