Interoperability of Distributed Component Systems Bryan Bentz, Jason Hayden, Upsorn Praphamontripong, Paul Vandal

Introduction Growth in Distributed Components Growth in Distributed Components –Multiple users –Multiple platforms –How can I interchange data efficiently? Various technologies have been introduced to leverage interoperability problems Various technologies have been introduced to leverage interoperability problems

Overview Research Path Research Path –XML and various interoperability technologies –Moved from XML to broader area Individual Research Individual Research –Finalize on November 6th Implementation Project Implementation Project –Tentative start date: November 6th

Semantic Web Extension of the current WWW Extension of the current WWW Web of distributed knowledge bases Web of distributed knowledge bases –Accessible by software agents –Simplified Interoperability Web Services Web Services –Locate, Select, Employ, Compose –Automation a priority “Collection of pages” => “Collection of services” “Collection of pages” => “Collection of services”

Ontologies Define structure of information Example: Price concept Example: Price concept Functionality: Functionality: –Design –Developed –Learned –Exchanged/Merged Layers: Metadata, Schema, Logical Layers: Metadata, Schema, Logical An ontology is a network of concepts, relationships,and constraints that provide context for data and information as well as processes

Ontologies (cont’d) Metadata layer: underlying resources and properties; RDF Metadata layer: underlying resources and properties; RDF Schema layer: represents hierarchy of concepts (“is-a” links); RDF-S Schema layer: represents hierarchy of concepts (“is-a” links); RDF-S Logical layer: represents more complex relationships. OWL Logical layer: represents more complex relationships. OWL Generality Detail/Richness

Web Services Software Agent Discovery of services Software Agent Discovery of services Invocation and monitoring of services Invocation and monitoring of services Composition of services: basic (pipe- like); active research area Composition of services: basic (pipe- like); active research area

Languages Languages: Languages: –UDDI: Universal Description, Discovery, Integration; IBM, MS (registry, etc.) –RDF: Resource Description Framework –RDF–S: RDF Schema –WSDL: Web Service Definition Language –WSMO: Web Service Modeling Ontology –DAML: Darpa Agent Markup Language –OIL: Ontology Inference Layer; EU –OWL: Web Ontology Language (successor to DAML+OIL) –ebXML: electronic business using XML; UN

Summary The Semantic Web will allow software agents to discover and interact with a wide variety of knowledge bases and services; The Semantic Web will allow software agents to discover and interact with a wide variety of knowledge bases and services; This requires layered metalanguages, to support the service discovery and negotiation of data exchange; This requires layered metalanguages, to support the service discovery and negotiation of data exchange; These standards are evolving. These standards are evolving.

OpenDocument OpenDocument proposed by Oasis OpenDocument proposed by Oasis Composed of input by major corporations Composed of input by major corporations Based off file format from OpenOffice Based off file format from OpenOffice Ratified on May 1, 2005 Ratified on May 1, 2005 Multiple applications support format Multiple applications support format Royalty free distribution Royalty free distribution

Advantages & Disadvantages Advantages Advantages –Not a binary file format –Ratified standard –Portability across multiple editors Disadvantages Disadvantages –No standard format for formulas –Multiple ways to define the same properties

Composition of OpenDocument file Compressed archive file containing the following files and directories Compressed archive file containing the following files and directories –Content.xml –Sytles.xml –Meta.xml –Settings.xml –Pictures/ –Meta-inf/

Testing OpenDocument files are opened in multiple editors. OpenDocument files are opened in multiple editors. The formatting and readability of text is examined The formatting and readability of text is examined Spreadsheets with complex formulas are studied to see if portability exists Spreadsheets with complex formulas are studied to see if portability exists

Software Retrieval Reusable assets Reusable assets –Analysis documents –Design documents –Source codes –Executable objects Aspect based component description Aspect based component description –Syntactic aspect –Functional – Behavioral aspect –Non-functional aspect –Licensing aspect

` ` ` ` XML-based Aspect Representation Pay-Per-Use Pay-Per-Use </Component> Syntactic aspect Functional aspect Non-functional aspect Licensing aspect

Basic Architecture Library Component Specification Component Analyzer Lexical AnalyzerSyntactic Analyzer Semantic Analyzer Query Component Specification Component Analyzer Lexical AnalyzerSyntactic Analyzer Semantic Analyzer Extracted library component specification Match Maker Extracted query component specification Retrieved components

Software Component Retrieval System M1 M2 Mn Matchmakers … … … Query Interface Publish Interface Component Description Repository Licensing server Component IntegratorsComponent Vendors (Varadarajan, et. al. “Componentxchange: An E-Exchange for Software Components”, WWW’10, 2001)

Distributed Data Warehouses Numerous Interoperability Issues Numerous Interoperability Issues –Metadata Interchange Protocols –Metadata Management –Repository Architectures –Heterogeneous Metadata Heterogeneous Metadata Heterogeneous Metadata –Many tools have vendor specific metadata –Many different interfaces and bridges –Difficult to introduce new components Possibility for a Metadata standard? Possibility for a Metadata standard?

Repository Example Repository Database Tool

Common Warehouse Metamodel Common Metamodel Common Metamodel –Metamodel standard for all data warehouse tools –Designed for the data warehouse domain –Allows extensibility of metadata from standard model Model Driven Approach Model Driven Approach –CWM is expressed in UML –CWM is interchanged via XML –Use MOF in order to fuse UML and XML Products of CWM Products of CWM –XMI/XML for metadata interchange –DTD to validate XMI/XML documents –API for metadata manipulation

A Common Metamodel Common Data Used for CWM Metamodel Tool A MetamodelTool B Metamodel Tool C Metamodel

Repository Example Revisited Repository Database Tool

Return on Investment ROI – Return on Investment ROI – Return on Investment –Business decisions made on ROI –ROI will increase with the lifespan of an application Metadata Bridges = Low Return on Investment Metadata Bridges = Low Return on Investment –Can’t substitute another tool in without creating another bridge Global Metadata = High return on Investment Global Metadata = High return on Investment –Robust –Plug and Play –Pick and Choose best component

Further Research Metadata Management Strategies Metadata Management Strategies Affect of Extensibility in CWM Affect of Extensibility in CWM CWM Package Hierarchy CWM Package Hierarchy –Individual Package Functions –Relationship with Meta-Object Facility Metadata Repository Architectures Metadata Repository Architectures –Strengths/Weaknesses –Return on Investment

Questions