A Taxonomy of Workflow Management Systems for Grid Computing

With the advent of Grid and application technologies, scientists and engineers are building more and more complex applications to manage and process large data sets, and execute scientific experiments on distributed resources. Such application scenarios require means for composing and executing complex workflows. Therefore, many efforts have been made towards the development of workflow management systems for Grid computing. In this paper, we propose a taxonomy that characterizes and classifies various approaches for building and executing workflows on Grids. We also survey several representative Grid workflow systems developed by various projects world-wide to demonstrate the comprehensiveness of the taxonomy. The taxonomy not only highlights the design and engineering similarities and differences of state-of-the-art in Grid workflow systems, but also identifies the areas that need further research.Comment: 29 pages, 15 figure

Security oriented e-infrastructures supporting neurological research and clinical trials

The neurological and wider clinical domains stand to gain greatly from the vision of the grid in providing seamless yet secure access to distributed, heterogeneous computational resources and data sets. Whilst a wealth of clinical data exists within local, regional and national healthcare boundaries, access to and usage of these data sets demands that fine grained security is supported and subsequently enforced. This paper explores the security challenges of the e-health domain, focusing in particular on authorization. The context of these explorations is the MRC funded VOTES (Virtual Organisations for Trials and Epidemiological Studies) and the JISC funded GLASS (Glasgow early adoption of Shibboleth project) which are developing Grid infrastructures for clinical trials with case studies in the brain trauma domain

Global Grids and Software Toolkits: A Study of Four Grid Middleware Technologies

Grid is an infrastructure that involves the integrated and collaborative use of computers, networks, databases and scientific instruments owned and managed by multiple organizations. Grid applications often involve large amounts of data and/or computing resources that require secure resource sharing across organizational boundaries. This makes Grid application management and deployment a complex undertaking. Grid middlewares provide users with seamless computing ability and uniform access to resources in the heterogeneous Grid environment. Several software toolkits and systems have been developed, most of which are results of academic research projects, all over the world. This chapter will focus on four of these middlewares--UNICORE, Globus, Legion and Gridbus. It also presents our implementation of a resource broker for UNICORE as this functionality was not supported in it. A comparison of these systems on the basis of the architecture, implementation model and several other features is included.Comment: 19 pages, 10 figure

Tool support for security-oriented virtual research collaborations

Collaboration is at the heart of e-Science and e-Research more generally. Successful collaborations must address both the needs of the end user researchers and the providers that make resources available. Usability and security are two fundamental requirements that are demanded by many collaborations and both concerns must be considered from both the researcher and resource provider perspective. In this paper we outline tools and methods developed at the National e-Science Centre (NeSC) that provide users with seamless, secure access to distributed resources through security-oriented research environments, whilst also allowing resource providers to define and enforce their own local access and usage policies through intuitive user interfaces. We describe these tools and illustrate their application in the ESRC-funded Data Management through e-Social Science (DAMES) and the JISC-funded SeeGEO projects

Grid infrastructures supporting paediatric endocrinology across Europe

Paediatric endocrinology is a highly specialised area of clinical medicine with many experts with specific knowledge distributed over a wide geographical area. The European Society for Paediatric Endocrinology (ESPE) is an example of such a body of experts that require regular collaboration and sharing of data and knowledge. This paper describes work, developed as a corollary to the VOTES project [1] and implementing similar architectures, to provide a data grid that allows information to be efficiently distributed between collaborating partners, and also allows wide-scale analyses to be run over the entire data-set, which necessarily involves crossing domain boundaries and negotiating data access between administrations that only trust each other to a limited degree

AstroGrid-D: Grid Technology for Astronomical Science

We present status and results of AstroGrid-D, a joint effort of astrophysicists and computer scientists to employ grid technology for scientific applications. AstroGrid-D provides access to a network of distributed machines with a set of commands as well as software interfaces. It allows simple use of computer and storage facilities and to schedule or monitor compute tasks and data management. It is based on the Globus Toolkit middleware (GT4). Chapter 1 describes the context which led to the demand for advanced software solutions in Astrophysics, and we state the goals of the project. We then present characteristic astrophysical applications that have been implemented on AstroGrid-D in chapter 2. We describe simulations of different complexity, compute-intensive calculations running on multiple sites, and advanced applications for specific scientific purposes, such as a connection to robotic telescopes. We can show from these examples how grid execution improves e.g. the scientific workflow. Chapter 3 explains the software tools and services that we adapted or newly developed. Section 3.1 is focused on the administrative aspects of the infrastructure, to manage users and monitor activity. Section 3.2 characterises the central components of our architecture: The AstroGrid-D information service to collect and store metadata, a file management system, the data management system, and a job manager for automatic submission of compute tasks. We summarise the successfully established infrastructure in chapter 4, concluding with our future plans to establish AstroGrid-D as a platform of modern e-Astronomy.Comment: 14 pages, 12 figures Subjects: data analysis, image processing, robotic telescopes, simulations, grid. Accepted for publication in New Astronom

User-oriented security supporting inter-disciplinary life science research across the grid

Understanding potential genetic factors in disease or development of personalised e-Health solutions require scientists to access a multitude of data and compute resources across the Internet from functional genomics resources through to epidemiological studies. The Grid paradigm provides a compelling model whereby seamless access to these resources can be achieved. However, the acceptance of Grid technologies in this domain by researchers and resource owners must satisfy particular constraints from this community - two of the most critical of these constraints being advanced security and usability. In this paper we show how the Internet2 Shibboleth technology combined with advanced authorisation infrastructures can help address these constraints. We demonstrate the viability of this approach through a selection of case studies across the complete life science spectrum