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The tasks to authorize users access to grid resources and to authorize their regulated consumption is studied and some key functionality is identified. A novel authorization infrastructure is proposed by combining the Virtual User System (VUS) for dynamically assigning local pool-accounts to grid-users and the SweGrid Accounting System (SGAS) for grid-wide usage logging and real-time enforcement of resource pre-allocations.

We present an approach for development of Grid resource management tools, where we put into practice internationally established high-level views of future Grid architectures. The approach addresses fundamental Grid challenges and strives towards a future vision of the Grid where capabilities are made available as independent and dynamically assembled utilities, enabling run-time changes in the structure, behavior, and location of software. The presentation is made in terms of design heuristics, design patterns, and quality attributes, and is centered around the key concepts of co-existence, composability, adoptability, adaptability, changeability, and interoperability. The practical realization of the approach is illustrated by five case studies (recently developed Grid tools) high-lighting the most distinct aspects of these key concepts for each tool. The approach contributes to a healthy Grid ecosystem that promotes a natural selection of “surviving” components through competition, innovation, evolution, and diversity. In conclusion, this environment facilitates the use and composition of components on a per-component basis.

We present a generic and light-weight Grid workflow execution engine made available as a Grid service. A long-term goal is to facilitate the rapid development of application-oriented end-user workflow tools, while providing a high degree of Grid middleware-independence. The workflow engine is designed for workflow execution, independent of client tools for workflow definition. A flexible plugin-structure for middleware-integration provides a strict separation of the workflow execution and the processing of individual tasks, such as computational jobs or file transfers. The light-weight design is achieved by focusing on the generic workflow execution components and by leveraging state-of-the art Grid technology, e.g., for state management. The current prototype is implemented using the Globus Toolkit 4 (GT4) Java WS Core and has support for executing workflows produced by Karajan. It also includes plugins for task execution with GT4 as well as a high-level Grid job management framework.

We propose a multi-tiered architecture for middleware-independent Grid job management. The architecture consists of a number of services for well-defined tasks in the job management process, offering complete user-level isolation of servicecapabilities, multiple layers of abstraction, control, and fault tolerance. The middleware abstraction layer comprises components for targeted job submission, job control and resource discovery. The brokered job submission layer offers a Grid view on resources, including functionality for resource brokering and submission of jobs to selected resources. The reliable job submission layer includes components for fault tolerant execution of individual jobs and groups of independentjobs, respectively. The architecture is proposed as a composable set of tools rather than a monolithic solution, allowing users to select the individual components of interest. The prototype presented is implemented using the Globus Toolkit 4, integrated with the Globus Toolkit 4 and NorduGrid/ARC middlewares and based on existing and emerging Grid standards. A performance evaluation reveals that the overhead for resource discovery, brokering, middleware-specific format conversions, job monitoring, fault tolerance, and management of individual and groups of jobs is sufficiently small to motivate the use of the framework.

There is an immediate need to develop Grid interfaces for a large set of numerical software libraries, in order to make popular software of today available in the computing infrastructure of tomorrow. As this development work tend to be both tedious and error-prone, this contribution presents a semi-automatic process for generating the interfaces. The underlying principle is to use a front-end tuned for each numerical library and a back-end for each Grid environment considered. Then all library—Grid environment combinations can be generated with a small amount of manual work. The presentation of the main ideas is followed by a proof-of-concept implementation that generates NetSolve interfaces for the complete SLICOT software library, a numerical library comprising nearly 400 Fortran subroutines for numerical computations in the design and analysis of control systems.

This contribution presents the design and implementation of a bank service, constituting a key component in a recently developed Grid accounting system. The Grid accounting system maintains a Grid-wide view of the resources consumed by members of a virtual organization (VO). The bank is designed as an online service, managing the accounts of VO projects. Each service request is transparently intercepted by the accounting system, which acquires a reservation on a portion of the project’s bank account prior to servicing the request. Upon service completion, the account is charged for the consumed resources. We present the overall bank design and technical details of its major components, as well as some illustrative examples of relevant service interactions. The system, which has been implemented using the Globus Toolkit, is based on state-of-the-art Web and Grid services technology and complies with the Open Grid Services Architecture (OGSA).