JXTA平台上基于语义的P2P资源共享研究
摘要
随着Internet的快速发展,网络所蕴涵的信息量急剧地膨胀。现有基于Client/Server模式的搜索技术,存在着服务器单点失效、信息更新周期长、缺乏语义支持等不足,极大地限制着搜索结果在查准率和查全率两个方面的提高。如何在庞大的互联网上更有效地获得有价值的信息已成为人们日益关注的问题。
本文在综合应用P2P技术与语义Web技术的基础上,提出了一种基于语义本体OCSD的P2P网络资源搜索模型。该模型采用了混合式P2P网络结构,对等点根据各自的兴趣组成点组,每个组中选定一个集合点来响应组外查询请求,各个集合点之间互相连接,形成一个覆盖网,充分利用Internet闲散的边缘资源,减轻主干网络和关键点的负荷,有效解决了服务器单点失效、信息更新周期长等问题;依据ACM分类标准,利用protege工具构建了以计算机科学文献为主题的语义本体OCSD,达成P2P网络各对等点资源的统一描述和共享,保证了机器对资源的可理解性,提供了语义支持。针对当前各个P2P系统间不能相互兼容的问题,本文采用了Sun公司的新一代通用P2P开发平台JXTA,设计并部分实现了基于语义的P2P资源共享系统ORSS。
本文提出了的基于JXTA的P2P分布式搜索模型,借助Ontology的语义表达优势构建资源共享系统的方法,与现有的基于关键字搜索、目录式搜索、元搜索等搜索技术形成互补,达到了预期设计的目的。
The Internet's phenomenal impact and subsequent growth stemmed primarily from the open, public, worldwide networking it offers. Most current applications, however, use client-server technologies that incorporate networking as an ancillary, Single point of failure and value-added feature, and limit resources sharing to some extent. It has been a hot issue about how to get useful and valuable information in the tremendous Internet.
Nowadays a new integration concept based on the notion of Semantic Web is being developed. The concept assumes semantic annotation of Web resources and services to make them "understandable" by computers. On the other hand, emerging Peer-to-Peer technology and appropriate networks suite well to the increasingly decentralized nature of modern companies and their industrial and business processes. Some of the benefits of a P2P approach include: improving scalability by avoiding dependency on centralized points; eliminating the need for costly infrastructure by enabling direct communication among clients; and enabling resource aggregation.
On the basis of P2P technology and Semantic Web relevant technologies, This paper proposes a kind of web resources search module based on the Ontology OCSD. To resolve the compatibility problem existing in the P2P systems, JXTA is adopted as a general P2P development platform. Based on the study on JXTA, this thesis chooses the Hybrid P2P network model. Peers organize themselves into peer groups in accordance with their common interests. Each group selects a rendezvous peer to respond to the outside request. All rendezvous peers interconnect, forming a overlay network. According to ACM classification standards, we build the peer knowledge ontology OCSD with the protege tool, which described by the W3C standards OWL ontology language, and select computer scientific document as its subject, reaching on the unified description and sharing of the P2P network resources; choose the RDF/RDFS markup language to achieve the semantic tagging of the shared resources, achieve Ontology reasoning and data query with the Jena tool in the specific field to ensure that the resources is understandable for the machine; design and preliminary imply the P2P resource sharing system ORSS based on semantic. There is a real sense of exploration to further develop and improve the resources searching and sharing technology.
本文在综合应用P2P技术与语义Web技术的基础上,提出了一种基于语义本体OCSD的P2P网络资源搜索模型。该模型采用了混合式P2P网络结构,对等点根据各自的兴趣组成点组,每个组中选定一个集合点来响应组外查询请求,各个集合点之间互相连接,形成一个覆盖网,充分利用Internet闲散的边缘资源,减轻主干网络和关键点的负荷,有效解决了服务器单点失效、信息更新周期长等问题;依据ACM分类标准,利用protege工具构建了以计算机科学文献为主题的语义本体OCSD,达成P2P网络各对等点资源的统一描述和共享,保证了机器对资源的可理解性,提供了语义支持。针对当前各个P2P系统间不能相互兼容的问题,本文采用了Sun公司的新一代通用P2P开发平台JXTA,设计并部分实现了基于语义的P2P资源共享系统ORSS。
本文提出了的基于JXTA的P2P分布式搜索模型,借助Ontology的语义表达优势构建资源共享系统的方法,与现有的基于关键字搜索、目录式搜索、元搜索等搜索技术形成互补,达到了预期设计的目的。
The Internet's phenomenal impact and subsequent growth stemmed primarily from the open, public, worldwide networking it offers. Most current applications, however, use client-server technologies that incorporate networking as an ancillary, Single point of failure and value-added feature, and limit resources sharing to some extent. It has been a hot issue about how to get useful and valuable information in the tremendous Internet.
Nowadays a new integration concept based on the notion of Semantic Web is being developed. The concept assumes semantic annotation of Web resources and services to make them "understandable" by computers. On the other hand, emerging Peer-to-Peer technology and appropriate networks suite well to the increasingly decentralized nature of modern companies and their industrial and business processes. Some of the benefits of a P2P approach include: improving scalability by avoiding dependency on centralized points; eliminating the need for costly infrastructure by enabling direct communication among clients; and enabling resource aggregation.
On the basis of P2P technology and Semantic Web relevant technologies, This paper proposes a kind of web resources search module based on the Ontology OCSD. To resolve the compatibility problem existing in the P2P systems, JXTA is adopted as a general P2P development platform. Based on the study on JXTA, this thesis chooses the Hybrid P2P network model. Peers organize themselves into peer groups in accordance with their common interests. Each group selects a rendezvous peer to respond to the outside request. All rendezvous peers interconnect, forming a overlay network. According to ACM classification standards, we build the peer knowledge ontology OCSD with the protege tool, which described by the W3C standards OWL ontology language, and select computer scientific document as its subject, reaching on the unified description and sharing of the P2P network resources; choose the RDF/RDFS markup language to achieve the semantic tagging of the shared resources, achieve Ontology reasoning and data query with the Jena tool in the specific field to ensure that the resources is understandable for the machine; design and preliminary imply the P2P resource sharing system ORSS based on semantic. There is a real sense of exploration to further develop and improve the resources searching and sharing technology.
引文
[1]Crespo A,Garcia-Molina H.Semantic overlay networks for P2P systems.In:Moro G,Bergamaschi S,Aberer K,eds.Proc.of the 3rd Int'l Workshop on Agents and Peer-to-Peer Computing.Berlin:Springer-Verlag,2004:1-13.
[2]http://www.clip2.com/GnutellaProtocol04.pdf.
[3]Yang B.,Garcia-Molina H..Improving search in peer-to-peer networks.In:Rodrigues LET,Raynal M,Chen WSE,eds.Proc.of the 22nd Int'l Conf.on Distributed Computing Systems.Washington:IEEE Computer Society,2002:5-14.
[4]黄道颖,李祖鹏,庄雷等.分布式Peer-to-Peer网络Gnutella模型研究.计算机工程与应用.2003,39(5):60-63.
[5]KaIogeraki,V.,Gunopulos,D.,Zeinalipour-Yazti D..A Local Search Mechanism for Peer-to-Peer Networks.Proceedings of the Eleventh International Conference on Information and Knowledge Management,McLean,Virginia,USA,2002:300-307.
[6]E.Cohen and S.Shenker.Optimal replication in random search networks.Preprint,Optional 2001.
[7]Adamic L.,Lukose R.,Puniyani A.et al.Search in power-law networks.Phys.Rev.E.2001,64(4):046135.
[8]Crespo A,Garcia-Molina H.Routing indices for peer-to-peer systems.In:Sivilotti P,ed.Proc.of the Int'l Conf.on Distributed Computing Systems.Arizona:IEEE Computer Society,2002:23-34.
[9]黄道颖,刘刚,张尧等.利用Gnutella网络的拓扑特性改进其可扩展性.计算机工程与应用.2003,39(26):58-60.
[10]黄道颖,陈新,张安琳等.P2P网络Gnutella模型中搜索消息的路由机制及改进研究.计算机工程与应用.2003,39(25):13-15.
[11]Yang B.,Garcia-Molina H..Comparing hybrid peer-to-peer systems.Proceedings of the 27th VLDB Conference,Roma,Italy,2001:561-570.
[12]Nejdl W.,Wolf B.,Qu C.et al.Edutella:A P2P networking infrastructure based on RDF.Proceedings of the Eleventh International World Wide Web Conference,Honolulu,Hawaii,USA,2002:604-615.
[13]Ehrig M.,Haase P.,Siebes R.et al.The SWAP Data and Metadata Model for Semantics-Based Peer-to-Peer Systems.Proceedings of MATES-2003,First German Conference on Multiagent Technologies,Erfurt,Germany,2003:144-155.
[14]Joseph,S.R.H.NeuroGrid:Semantically Routing Queries in Peer-to-Peer Networks.International Workshop on Peer-to-Peer Computing,Pisa,ItaIy,2002:202-214.
[15]宋建涛,沙朝锋,杨智应等.语义对等网构造及搜索机制研究.计算机研究与发展.2004,41(4):645-652.
[16]Schlosser M,Sintek M.,Decker S.et al.A Scalable and Ontology-Based P2P Infrastructure for Semantic Web Services.Proceedings of the Second International Conference on Peer-to-Peer Computing,Linkopings,Sweden,2002:104-111.
[17]Zhou,J.,Dialani,V.,De Roure,D.et al.A Semantic Search Algorithm for Peer-to-Peer Open Hypermedia Systems.The First Workshop on Semantics in Peer-to-Peer and Grid Computing,Budapest,Hungary,2003:43-54.
[18]Tang C,Xu Z.,Mahalingam M..pSearch:Information Retrieval in Structured Overlays.ACM SIGCOMM Computer Communication Review.2003,33(1):89-94.
[19]Erdmann M.,Maedche A.,Schnurr H.-P.et al.From Manual to Semi-automatic Semantic Annotation:About Ontology-based Text Annotation Tools.Proceedings of the COLING 2000 Workshop on Semantic Annotation and Intelligent Content,Luxembourg,2000:33-35.
[20]http://www.w3.org/TR/2006/REC-xml-namesl 1-20060816/.
[21]Walsh N..A technical introduction to XML.Ann Arbor,MI:ArborText Inc.,1998.
[22]http://www.faqs.org/rfcs/rfc2396.html.
[23]http://co4.inrialpes.fr/xml/dlml/.
[24]http://www.w3.org/DesignIssues/Toolbox.html.
[25]http://www.w3.org/DesignIssues/Rules.html.
[26]Oram A.Peer-to-Peer:Harnessing the Power of Disruptive Technologies.Sebastopol:O'Reilly and Associates,2001.
[27]http://www.peer-to-peer.org
[28]http://www.oreilly.org
[29]Lv Q,Cao P,Cohen E.et al.Search and replication in unstructured peer-to-peer networks.Proc.of the 16th ACM Int'l Conf.on Supercomputing,New York,2002:84-95.
[30]Stoica I.,Morris R.,Karger D.et al.Chord:A Scalable Peer-to-Peer Look up Service for Internet Applications.Proceedings of ACM SIGCOMM'01.2001,31(4):149-160.
[31]Ratnasamy S.,Francis P.,Handley M.et al.A Scalable Content-addressable Network.Proceedings of ACM SIGCOMM'01.2001,31(4):161-172.
[32]Zhao B.,Huang L.,Stribling J..Tapestry:a resilient global-scale overlay for service deployment.IEEE Journal on Selected Areas in Communications.2004,22(1):41-53.
[33]http://www.napster.com.
[34]http://www.gnutella.com.
[35]http://www.intsci.ac.cn/users/luojw/P2P/index.html
[36]Cohen E.and Shenker S..Replication strategies in unstructured peer-to-peer networks.Computer Communication Review.2002,32(4):177-190.
[37]http://www.eurecom.fr/-kangasha/
[38]http://www.chord.com
[39]http://www.can.com
[40]http://www.pastry.com
[41]http://www.kazaa.com
[42]http://morpheus-os.com
[43]http://freenet.sourceforge.net
[44]http://www.ppcn.net
[45]http://www.hpl.hp.com/techreports/2002/HPL-2002-57R1.pdf
[46]杨广文,黄大正,肖侬.P2P计算深入底层与边缘.计算机世界报.2003,(40):B7-B8.
[47]吴胜浩,钟亦平,张世永.JXTA:新型的网络计算环境.计算机工程.2004,30(9):4-6.
[48]http://www.qqread.com/java/w632143600.html.
[49]https://jxta-guide.dev.java.net/source/browse/*checkout*/jxta-guide/trunk/src/guide_v2.5/JXSE_ProgGuide_v2.5.pdf.
[50]http://www.daml.org.
[51]Fensel D.Ontologies:A silver bullet for knowledge management and electronic commerce.New York:Springer Publishing Press,2003.
[52]邓志鸿,唐世渭,张铭等.Ontology研究综述.北京大学学报(自然科学版).2002,38(5):730-738.
[53]http://www.cyc.com.
[54]http://oil.semanticweb.0rg//.
[55]http://www.w3.org/2001/sw/WebOnt/.
[56]Gruber T R.Towards Principles for the Design of Ontologies Used for Knowledge Sharing.International Journal Human-Computer Studies.1995,43(5-6):907-928.
[57]https://jxta.dev.java.net/.
[58]http://www.v3.net.cn/Article/bckf/Java/200512/3999_3.html
[59]http://www.matrix.org.cn/thread.shtml?forum_id=4&view_id=16943.
[60]林泓,何巍.利用JXTA平台实现P2P服务的研究.武汉理工大学学报:信息与管理工程版.2005,27(2):38-41.
[61]Bernard Traversat,Ahkil Arora,Mohamed Abdelaziz,et al.Project JXTA 2.0 Super-Peer Virtual Network.Sun Microsystems white paper.
[62]吴慧良.对等网络计算平台JXTA的研究:(硕士学位论文).浙江:浙江大学,2003.
[63]Oaks S.,Traversat B.,Gong L..Jxta in a Nutshell.Sebastopol:O'Reilly & Associates,Inc.,2002.
[64]http://platfom.jxta.org/java/workinprogress/ rdv-hld.html
[65]黄鑫,庄雷.基于JXTA技术的Peer-to-Peer网络查询优化策略.微电子学与计算机.2004,21(8):106-110.
[66]Beckwith R.,Fellbaum C.,Gross D.et al.WordNet:A Lexical Database Organized on Psycholinguistic Principles.In:Zernik U.(ed.).Using On-line Resources to Build a Lexicon.Hillsdale,N.J.:Erlbaum,1990:211-231.
[67]Madhavan J.,A.Bernstein P.,Domingos P.et al.Representing and Reasoning about Mappings between Domain Models.Eighteenth National Conference on Artificial Intelligence,Edmonton,Alberta,Canada,2002:80-86.
[68]Madhavan J.,A.Bernstein P.,Rahm E..Generic Schema Matching with Cupid.Proceedings of the 27th International Conference on Very Large Data Bases,Roma,Italy,2001:49-58.
[69]http://jena.sourceforge.net/ontology/index.html.
[70]李兴隆.基于Ontology的文档检索:(硕士学位论文).沈阳:东北大学,2005.
[71]Doan A.,Madhavan J.,Domingos P.et al.Ontology Matching:A Machine Learning Approach.In:Staab S.and Studer R.(eds.).Handbook on Ontologies in Information Systems.Berlin:Springer-Velag,2003:397-416.
[72]Bouquet P.,Serafini L.,Zanobini S..Semantic Coordination:A New Approach and an Application.2nd International Semantic Web Conference,Sanibel-Captiva Islands,Florida,USA,2003:130-145.
[73]http://jena.sourceforge.net/tutorial/RDQL/.
[2]http://www.clip2.com/GnutellaProtocol04.pdf.
[3]Yang B.,Garcia-Molina H..Improving search in peer-to-peer networks.In:Rodrigues LET,Raynal M,Chen WSE,eds.Proc.of the 22nd Int'l Conf.on Distributed Computing Systems.Washington:IEEE Computer Society,2002:5-14.
[4]黄道颖,李祖鹏,庄雷等.分布式Peer-to-Peer网络Gnutella模型研究.计算机工程与应用.2003,39(5):60-63.
[5]KaIogeraki,V.,Gunopulos,D.,Zeinalipour-Yazti D..A Local Search Mechanism for Peer-to-Peer Networks.Proceedings of the Eleventh International Conference on Information and Knowledge Management,McLean,Virginia,USA,2002:300-307.
[6]E.Cohen and S.Shenker.Optimal replication in random search networks.Preprint,Optional 2001.
[7]Adamic L.,Lukose R.,Puniyani A.et al.Search in power-law networks.Phys.Rev.E.2001,64(4):046135.
[8]Crespo A,Garcia-Molina H.Routing indices for peer-to-peer systems.In:Sivilotti P,ed.Proc.of the Int'l Conf.on Distributed Computing Systems.Arizona:IEEE Computer Society,2002:23-34.
[9]黄道颖,刘刚,张尧等.利用Gnutella网络的拓扑特性改进其可扩展性.计算机工程与应用.2003,39(26):58-60.
[10]黄道颖,陈新,张安琳等.P2P网络Gnutella模型中搜索消息的路由机制及改进研究.计算机工程与应用.2003,39(25):13-15.
[11]Yang B.,Garcia-Molina H..Comparing hybrid peer-to-peer systems.Proceedings of the 27th VLDB Conference,Roma,Italy,2001:561-570.
[12]Nejdl W.,Wolf B.,Qu C.et al.Edutella:A P2P networking infrastructure based on RDF.Proceedings of the Eleventh International World Wide Web Conference,Honolulu,Hawaii,USA,2002:604-615.
[13]Ehrig M.,Haase P.,Siebes R.et al.The SWAP Data and Metadata Model for Semantics-Based Peer-to-Peer Systems.Proceedings of MATES-2003,First German Conference on Multiagent Technologies,Erfurt,Germany,2003:144-155.
[14]Joseph,S.R.H.NeuroGrid:Semantically Routing Queries in Peer-to-Peer Networks.International Workshop on Peer-to-Peer Computing,Pisa,ItaIy,2002:202-214.
[15]宋建涛,沙朝锋,杨智应等.语义对等网构造及搜索机制研究.计算机研究与发展.2004,41(4):645-652.
[16]Schlosser M,Sintek M.,Decker S.et al.A Scalable and Ontology-Based P2P Infrastructure for Semantic Web Services.Proceedings of the Second International Conference on Peer-to-Peer Computing,Linkopings,Sweden,2002:104-111.
[17]Zhou,J.,Dialani,V.,De Roure,D.et al.A Semantic Search Algorithm for Peer-to-Peer Open Hypermedia Systems.The First Workshop on Semantics in Peer-to-Peer and Grid Computing,Budapest,Hungary,2003:43-54.
[18]Tang C,Xu Z.,Mahalingam M..pSearch:Information Retrieval in Structured Overlays.ACM SIGCOMM Computer Communication Review.2003,33(1):89-94.
[19]Erdmann M.,Maedche A.,Schnurr H.-P.et al.From Manual to Semi-automatic Semantic Annotation:About Ontology-based Text Annotation Tools.Proceedings of the COLING 2000 Workshop on Semantic Annotation and Intelligent Content,Luxembourg,2000:33-35.
[20]http://www.w3.org/TR/2006/REC-xml-namesl 1-20060816/.
[21]Walsh N..A technical introduction to XML.Ann Arbor,MI:ArborText Inc.,1998.
[22]http://www.faqs.org/rfcs/rfc2396.html.
[23]http://co4.inrialpes.fr/xml/dlml/.
[24]http://www.w3.org/DesignIssues/Toolbox.html.
[25]http://www.w3.org/DesignIssues/Rules.html.
[26]Oram A.Peer-to-Peer:Harnessing the Power of Disruptive Technologies.Sebastopol:O'Reilly and Associates,2001.
[27]http://www.peer-to-peer.org
[28]http://www.oreilly.org
[29]Lv Q,Cao P,Cohen E.et al.Search and replication in unstructured peer-to-peer networks.Proc.of the 16th ACM Int'l Conf.on Supercomputing,New York,2002:84-95.
[30]Stoica I.,Morris R.,Karger D.et al.Chord:A Scalable Peer-to-Peer Look up Service for Internet Applications.Proceedings of ACM SIGCOMM'01.2001,31(4):149-160.
[31]Ratnasamy S.,Francis P.,Handley M.et al.A Scalable Content-addressable Network.Proceedings of ACM SIGCOMM'01.2001,31(4):161-172.
[32]Zhao B.,Huang L.,Stribling J..Tapestry:a resilient global-scale overlay for service deployment.IEEE Journal on Selected Areas in Communications.2004,22(1):41-53.
[33]http://www.napster.com.
[34]http://www.gnutella.com.
[35]http://www.intsci.ac.cn/users/luojw/P2P/index.html
[36]Cohen E.and Shenker S..Replication strategies in unstructured peer-to-peer networks.Computer Communication Review.2002,32(4):177-190.
[37]http://www.eurecom.fr/-kangasha/
[38]http://www.chord.com
[39]http://www.can.com
[40]http://www.pastry.com
[41]http://www.kazaa.com
[42]http://morpheus-os.com
[43]http://freenet.sourceforge.net
[44]http://www.ppcn.net
[45]http://www.hpl.hp.com/techreports/2002/HPL-2002-57R1.pdf
[46]杨广文,黄大正,肖侬.P2P计算深入底层与边缘.计算机世界报.2003,(40):B7-B8.
[47]吴胜浩,钟亦平,张世永.JXTA:新型的网络计算环境.计算机工程.2004,30(9):4-6.
[48]http://www.qqread.com/java/w632143600.html.
[49]https://jxta-guide.dev.java.net/source/browse/*checkout*/jxta-guide/trunk/src/guide_v2.5/JXSE_ProgGuide_v2.5.pdf.
[50]http://www.daml.org.
[51]Fensel D.Ontologies:A silver bullet for knowledge management and electronic commerce.New York:Springer Publishing Press,2003.
[52]邓志鸿,唐世渭,张铭等.Ontology研究综述.北京大学学报(自然科学版).2002,38(5):730-738.
[53]http://www.cyc.com.
[54]http://oil.semanticweb.0rg//.
[55]http://www.w3.org/2001/sw/WebOnt/.
[56]Gruber T R.Towards Principles for the Design of Ontologies Used for Knowledge Sharing.International Journal Human-Computer Studies.1995,43(5-6):907-928.
[57]https://jxta.dev.java.net/.
[58]http://www.v3.net.cn/Article/bckf/Java/200512/3999_3.html
[59]http://www.matrix.org.cn/thread.shtml?forum_id=4&view_id=16943.
[60]林泓,何巍.利用JXTA平台实现P2P服务的研究.武汉理工大学学报:信息与管理工程版.2005,27(2):38-41.
[61]Bernard Traversat,Ahkil Arora,Mohamed Abdelaziz,et al.Project JXTA 2.0 Super-Peer Virtual Network.Sun Microsystems white paper.
[62]吴慧良.对等网络计算平台JXTA的研究:(硕士学位论文).浙江:浙江大学,2003.
[63]Oaks S.,Traversat B.,Gong L..Jxta in a Nutshell.Sebastopol:O'Reilly & Associates,Inc.,2002.
[64]http://platfom.jxta.org/java/workinprogress/ rdv-hld.html
[65]黄鑫,庄雷.基于JXTA技术的Peer-to-Peer网络查询优化策略.微电子学与计算机.2004,21(8):106-110.
[66]Beckwith R.,Fellbaum C.,Gross D.et al.WordNet:A Lexical Database Organized on Psycholinguistic Principles.In:Zernik U.(ed.).Using On-line Resources to Build a Lexicon.Hillsdale,N.J.:Erlbaum,1990:211-231.
[67]Madhavan J.,A.Bernstein P.,Domingos P.et al.Representing and Reasoning about Mappings between Domain Models.Eighteenth National Conference on Artificial Intelligence,Edmonton,Alberta,Canada,2002:80-86.
[68]Madhavan J.,A.Bernstein P.,Rahm E..Generic Schema Matching with Cupid.Proceedings of the 27th International Conference on Very Large Data Bases,Roma,Italy,2001:49-58.
[69]http://jena.sourceforge.net/ontology/index.html.
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