An Integrated Methodology for Creating Composed Web/Grid Services

This thesis presents an approach to design, specify, validate, verify, implement, and evaluate composed web/grid services. Web and grid services can be composed to create new services with complex behaviours. The BPEL (Business Process Execution Language) standard was created to enable the orchestration of web services, but there have also been investigation of its use for grid services. BPEL specifies the implementation of service composition but has no formal semantics; implementations are in practice checked by testing. Formal methods are used in general to define an abstract model of system behaviour that allows simulation and reasoning about properties. The approach can detect and reduce potentially costly errors at design time. CRESS (Communication Representation Employing Systematic Specification) is a domainindependent, graphical, abstract notation, and integrated toolset for developing composite web service. The original version of CRESS had automated support for formal specification in LOTOS (Language Of Temporal Ordering Specification), executing formal validation with MUSTARD (Multiple-Use Scenario Testing and Refusal Description), and implementing in BPEL4WS as the early version of BPEL standard. This thesis work has extended CRESS and its integrated tools to design, specify, validate, verify, implement, and evaluate composed web/grid services. The work has extended the CRESS notation to support a wider range of service compositions, and has applied it to grid services as a new domain. The thesis presents two new tools, CLOVE (CRESS Language-Oriented Verification Environment) and MINT (MUSTARD Interpreter), to respectively support formal verification and implementation testing. New work has also extended CRESS to automate implementation of composed services using the more recent BPEL standard WS-BPEL 2.0

Orchestrating Grid Services using BPEL and Globus Toolkit 4

Grid services exploit an emerging distributed computing technology that offers possibilities for distributed resource sharing and collaboration. The standards for WSRF (Web Service Resource Framework) have allowed grid services to converge more closely on web services. Composing web services has attracted significant effort and commercial interest. This has resulted in BPEL (Business Process Execution Logic) as a standard way of orchestrating web services. Because of the similarities with web services, there is a natural question of whether grid services can be orchestrated in like manner. It is explained how CRESS (Chisel Representation Employing Systematic Specification) has been extended to describe grid service composition. It will be seen how BPEL has been adapted for this purpose, using ActiveBPEL as the orchestration engine and Globus Toolkit 4 as the grid service container. The problems arising with orchestrating grid services are discussed, along with possible workarounds

Automated Analysis and Implementation of Composed Grid Services

Service composition allows web services to be combined into new ones. Web service composition is increasingly common in mission-critical applications. It has therefore become important to verify the correctness of web service composition using formal methods. The composition of grid services is a similar but new goal. We have previously developed an abstract graphical notation called CRESS for describing composite grid services. We have demonstrated that it is feasible to automatically generate service implementations as well as formal specifications from CRESS descriptions. The automated service implementations use orchestration code in BPEL, along with the service interfaces and data types in WSDL and XSD respectively for all services. CRESS-generated BPEL implementations currently do not useWSRF features such as implicit endpoint references for WS-Resources and interfacing to standard WSRF port types. CRESS-generated formal models use the standardised process algebra LOTOS. Service behaviour is modelled by processes, while service data types are modelled as abstract data types. Simulation and validation of the generated LOTOS specifications can be performed. In this paper, we illustrate how CRESS can be further extended to improve its generation of service compositions, specifically for WSRF services implemented using Globus Toolkit 4. We also show how to facilitate use of the generated LOTOS specifications with the CADP toolbox

Graphical Composition of Grid Services

Grid services and web services have similarities but also significant differences. Although conceived for web services, it is seen how BPEL (Business Process Execution Logic) can be used to orchestrate a collection of grid services. It is explained how CRESS (Chisel Representation Employing Systematic Specification) has been extended to describe grid service composition. The CRESS descriptions are automatically converted into BPEL/WSDL code for practical realisation of the composed services. This achieves orchestration of grid services deployed using the widely used Globus Toolkit and ActiveBPEL interpreter. The same CRESS descriptions are automatically translated into LOTOS, allowing systematic checks for interoperability and logical errors prior to implementation

Enabling Quantitative Data Analysis on Cyberinfrastructures and Grids

The social, behavioral and economic sciences (SBEs) do not currently benefit from a unified workflow environment for the quantitative analysis of social survey data. Some unified models integrating data storage, data management and data analysis do exist, for example the NESSTAR, IPUMS and LIS projects. However all of these services are focused on a limited number of data resources and functionalities. The Cyberinfrastructure could be exploited to develop and support a more generic workflow environment. In this paper, we build upon earlier work in providing a specialist data access service to social scientists (the GEODE project), to outline a proposed framework for a generic quantitative social science infrastructural service based on open standards

GEODE – Sharing Occupational Data Through The Grid

The ESRC funded Grid Enabled Occupational Data Environment (GEODE) project is conceived to facilitate and virtualise occupational data access through a grid environment. Through GEODE it is planned that occupational data users from the social sciences can access curated datasets, share micro datasets, and perform statistical analysis within a secure virtual community. The Michigan Data Documentation Initiative (DDI) is used to annotate the datasets with social science specific metadata to provide for better semantics and indexes. GEODE uses the Globus Toolkit and the Open Grid Service Architecture – Data Access and Integration (OGSA-DAI) software as the Grid middleware to provide data access and integration. Users access and use occupational data sets through a GEODE web portal. This portal interfaces with the Grid infrastructure and provides useroriented data searches and services. The processing of CAMSIS (Cambridge Social Interaction and Stratification) measures is used as an illustrative example of how GEODE provides services for linking occupational information. This paper provides an overview of the GEODE work and lessons learned in applying Grid technologies in this domain

Development of a Grid Enabled Occupational Data Environment

The GEODE project is developing user-oriented Grid-based services, accessible via a portal, for social scientists who require and use 'occupational information' within their research. There are many complexities associated with social scientists’ use of data on individual occupations. These arise for example from the availability of numerous alternative occupational classifications, and the use of different occupational definitions across countries. This paper describes how the GEODE project is developing an online service which acts as a facility supporting access to numerous occupational information resources. This is achieved through an integrated Grid service which uses a Globus Toolkit 4 infrastructure and OGSA-DAI (Database Access and Integration) middleware to provide the necessary data indexing and matching services, accessed through a user-oriented front-end portal (using GridSphere). The paper discusses issues in the implementation and organization of these services

Metadata Creation, Transformation and Discovery for Social Science Data Management: The DAMES Project Infrastructure

This paper discusses the use of metadata, underpinned by DDI (Data Documentation Initiative), to support social science data management. Social science data management refers broadly to the discovery, preparation, and manipulation of social science data for the purposes of research and analysis. Typical tasks include recoding variables within a dataset, and linking data from different sources. A description is given of the DAMES project (Data Management through e-Social Science), a UK project which is building resources and services to support quantitative social science data management activities. DAMES provides generic facilities for performing (and recording) operations on data. Specific resources include support for analysis through micro-simulation, and support for access to specialist data on occupations, educational qualifications, measures of ethnicity and immigration, social care, and mental health. The DAMES project tools and services can generate, use, transform, and search metadata that describe social science datasets (including microdata from social survey datasets and aggregate-level macrodata). On DAMES, these metadata are described by various standards including DDI Version 2, DDI Version 3, JSDL (Job Submission Definition Language), and the purpose-designed JFDL (Job Flow Definition Language). The paper describes how DAMES uses metadata with a range of resources that are integrated with a job execution infrastructure, a Web portal, and a tool for data fusion

Rigorous Development of Composite Grid Services

CRESS (Communication Representation Employing Systematic Specification) is introduced as notation, a methodology and a toolset for service development. The article focuses on rigorous development of composite grid services, with particular emphasis on the principles behind the methodology. A straightforward graphical notation is used to describe grid services. These are then automatically specified, analysed and implemented. Analysis includes formal verification of desirable service properties, formal validation of test scenarios, testing of implementation functionality, and evaluation of implementation performance. The case study that illustrates the approach is document content analysis to compare two pieces of text. This involves two composite services supported by two partner services. The usability of the service design notation is assessed, and a comparison is made of the approach with similar ones. These show that the CRESS approach to developing services is usable and more complete than other comparable approaches

Enabling quantitative data analysis through e-infrastructures

This paper discusses how quantitative data analysis in the social sciences can engage with and exploit an e-Infrastructure. We highlight how a number of activities which are central to quantitative data analysis, referred to as ‘data management’, can benefit from e-infrastructure support. We conclude by discussing how these issues are relevant to the DAMES (Data Management through e-Social Science) research Node, an ongoing project that aims to develop e-Infrastructural resources for quantitative data analysis in the social sciences