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ppt - Discovery of Web Services in a Federated Registry Environment


									Discovery of Web Services in a
Federated Registry Environment

     Kaarthik Sivashanmugam, Kunal Verma, Amit Sheth

    Large Scale Distributed Information Systems (LSDIS) Lab
     Department of Computer Science, University of Georgia

 Introduction
 MWSDI (METEOR-S Web Service Discovery
 Extended Registries Ontology
 Characterizing Registry Federations
 TModel Support for Federations
 Publishing and Discovery
 Conclusions
 Service Oriented Architectures are being proposed to meet
  dynamic business environments

 Web Services are XML based instantiations of SOA

 UDDI is a crucial of part of Web Service Triangle

 UDDI aims to extend the reach of
  the enterprise both as provider
  and consumer of business services.

                                                  SOA Triangle

 Initial vision of UDDI
  Replication of centralized UBRs
 Businesses will be businesses
  Need privacy, security, trust
  Rise of private and semi-private registries
 UDDI version 3 (and presumably version 4)
  provide support for distributed registries

 This paper presents the idea of creating
  Registry Federations
 Registry Federation is defined as a “group of
  co-operating registries” that provide
  transparent access to all member registries
 Examples of federations
  Two companies X and Y share their registries
  Federation of all registries in Auto parts domains
METEOR-S Web Service Discovery
Infrastructure (MWSDI)
 METEOR-S1 is a project which deals with all
  stages of Semantic Web Processes
 Our approach involves using the current
  industry standards infrastructure to add
 MWSDI deals with adding semantics to UDDI
 Provides transparent access to UDDI
  registries based on their domain or federation
Extended Registries Ontologies (XTRO)

 Provides a multi-
  faceted view of all
  registries in MWSDI
   Federations
   Domains
   Registries                      Registry
                      Federation            belongsTo

Types of Queries Supported
 What is the access URL, available data model or type of the
  registry R?
 Does the registry R support the ontology O?
 Which are the registries available under the business domain B?
 Is the registry X a member of the registry federation Y?
 Which registries pertain to the domains that support the
  ontologies O1 and O2?
 Get all the registry federations that belong to the domain D?
 Find all the registries that are categorized under the node N in
  the taxonomy (or ontology) C?
MWSDI Implementation

 Peer to peer network based on JXTA protocol
 Different types of peers based on their roles
   Gateway Peer
     Handles addition of new registries in MWSDI
     Responsible for updating registries ontology and propagating
      the changes to other peers
   Registry Operator Peers
     Each registry providing semantic publication and discovery
      must provide an operator peer
     Must implement generic publishing and discovery interface
      provided by MWSDI
     Potential mediators between UDDI and ebXML
MWSDI Implementation
 Peer roles (contd.)
   Auxiliary peers
     Act as providers of Registries Ontology to their clients
     Propagate changes in the ontology to their neighbors
   Client peers
     Transient peers to provide a GUI for accessing (publishing
      services and querying for services) registries in MWSDI
 Peer protocols
   All peers must support JXTA specific protocols
     Peer Discovery Protocol and the Pipe Binding Protocol
   All peers must also support MWSDI specific protocols
MWSDI Specific Protocols2

 Peer initiation Protocol
     Defines initiation of new registries in MWSDI
     Defines propagation of changes in Registries
 Client Peer Interaction Protocol
     Defined APIs and interactions for semantics
      publications and discovery
     Defines distribution of the registries ontology

2[Verma et al., 2004] METEOR–S WSDI: A Scalable Infrastructure of Registries for Semantic Publication
and Discovery of Web Services, Journal of Information Technology and Management (to appear, 2004)
Characterizing Registry Federations

 Can use relevant work in federated
  databases3 to characterize registry
 We characterize registry federations in three
  Data distribution
  Structural and semantic heterogeneity

  3A. Sheth and J. Larson, “Federated Databases: Architectures and
  Issues,” ACM Computing Surveys, 22 (3), September 1990, pp. 183-236
Data Distribution

 Different schemes possible
  Hierarchical and non hierarchical
 MWSDI provides multi-dimensional
  partitioning with the help of Registries
  Domains and federations
Structural and Semantic Heterogeneity

 Structural Heterogeneity
  Different data models like UDDI and ebXML
 Semantic Heterogeneity
  Which services have the same functionality
 MWSDI deals with semantic heterogeneity
  Only deals with UDDI registries
  Ontologies are used to resolve semantic
  T-Model directories to handle semantic
   heterogeneity across registries in a federation

 Can registries be accessed independently of
  the federation ?
 Can the registries support different
  mechanisms for publications and discovery
 Autonomy in MWSDI
 Registries can be accessed independently
 Registries can support different mechanisms for
  semantic publication and discovery as long they
  support the generic interface
TModels and TModel Directory

 SK can you please 3-4 slides for this
Querying for a Registry

 R = <f, d, o, r>
 f corresponds to the names of the registry
 d corresponds to the business domains
 o corresponds to set of ontologies
 r corresponds to a set of registry
 R = < {F1,F2}, {D2, D3}, {O1, O2, O3, O4}, {} >
Result of the sample query

 Presented an approach for accessing
  distributed registries
 Used Registries ontology to provide multi
  faceted distribution and querying
 There will be many registries
  This is an potential approach to handle them

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