Daniele Lezzi

The GSI plug-in for gSOAP: enhanced security, performance, and reliability

In this paper we report on the current status of the GSI plug-in for gSOAP, an open source solution to the problem of securing Web services in grid environments.

Secure Web Services with Globus GSI and gSOAP

In this paper we describe a plug-in for the gSOAP Toolkit that allows development of Web Services exploiting the Globus Security Infrastructure (GSI). Our plug-in allows the development of GSI enabled Web Services and clients, with full support for mutual authentication/authorization, delegation of credentials and connection caching. The software provides automatic, transparent transport-level security for Web Services and is freely available.

iGrid, a novel grid information service

In this paper we describe iGrid, a novel Grid Information Service based on the relational model. iGrid is developed within the European GridLab project by the ISUFI Center for Advanced Computational Technologies (CACT) of the University of Lecce, Italy. Among iGrid requirements there are security, decentralized control, support for dynamic data and the possibility to handle users and/or application supplied information, performance and scalability. The iGrid Information Service has been specified and carefully designed to meet these requirements.

Resource and service discovery in the igrid information service

In this paper we describe resource and service discovery mechanisms available in iGrid, a novel Grid Information Service based on the relational model. iGrid is developed within the GridLab project by the ISUFI Center for Advanced Computational Technologies (CACT) at the University of Lecce, Italy and it is deployed on the European GridLab testbed. The GridLab Information Service provides fast and secure access to both static and dynamic information through a GSI enabled web service. Besides publishing system information, iGrid also allow publication of users or service supplied information. The adoption of the relational model provides a flexible model for data, and the hierarchical distributed architecture provides scalability and fault tolerance.

The Design and Implementation of the GridLab Information Service

The grid computing paradigm emerged recently as a new field distinguished from traditional distributed computing because of its focus on large-scale resource sharing and innovative high-performance applications. The grid infrastructure ties together a number of Virtual Organizations, that reflect dynamic collections of individuals, institutions and computational resources. Flexible, secure and coordinated resource sharing among VOs requires the availability of an information rich environment to support resource discovery and decision making processes. The Globus Toolkit provides applications developers with the Monitoring and Discovery Service (MDS) to support development of grid-aware applications, able to exploit the knowledge about current grid status and configuration to adapt themselves to changes in heterogeneous, dynamic environments. In this paper we describe the design and implementation of the GridLab Information Service.

Web services for a biomedical imaging portal

TACWeb (TAC images on the Web), is a Web-based Grid portal, developed at the CACT/ISUFI laboratory of the University of Lecce for the management of biomedical images in a distributed environment. TACWeb, building on top of the Globus Toolkit, is an interactive environment that deals with complex users requests, regarding the acquisition of biomedical data, the processing and delivering of biomedical images, using the power and security of computational grids. Recently, Grid technologies are being integrated with Web services technologies to provide a framework for interoperable application-to-application interaction. In this paper we present an evolution of the TACWeb architecture that is compliant with the Web services approach and its main functionalities. In such a system, the basic capabilities are encapsulated and exposed as Web services allowing the development of new health applications as a composition of such services.

The GSI plug-in for gSOAP: building cross-grid interoperable secure grid services

Increasingly, grid computing is becoming the paradigm of choice for building large-scale complex scientific applications. These applications are characterized as being computationally and/or data intensive, requiring computational power and storage resources well beyond the capability of a single computer. Grid environments provide distributed, geographically spread computing and storage resources made available to scientists belonging to Virtual Organizations; resource sharing is tightly controlled across multiple administrative domains through established service-level agreements. The adoption of Service-Oriented Architectures leads to grid environments characterized by grid services built using Web Services technologies that can be composed as needed to create arbitrarily complex workflows. In this context, security is a key issue that must be taken into account; another concern is interoperability among grids, a fundamental building block to develop grid-aware applications that can benefit from multiple grid environments. We present the GSI plug-in for gSOAP, an open source solution to the problem of securing Web Services in grid environments providing full interoperability between grid environments based on the Globus Toolkit and gLITE middleware.

Near real-time parallel processing and advanced data management of SAR images in grid environments

In this paper, we describe the process of parallelizing an existing, production level, sequential Synthetic Aperture Radar (SAR) processor based on the Range-Doppler algorithmic approach. We show how, taking into account the constraints imposed by the software architecture and related software engineering costs, it is still possible with a moderate programming effort to parallelize the software and present an message-passing interface (MPI) implementation whose speedup is about 8 on 9 processors, achieving near real-time processing of raw SAR data even on a moderately aged parallel platform. Moreover, we discuss a hybrid two-level parallelization approach that involves the use of both MPI and OpenMP. We also present GridStore, a novel data grid service to manage raw, focused and post-processed SAR data in a grid environment. Indeed, another aim of this work is to show how the processed data can be made available in a grid environment to a wide scientific community, through the adoption of a data grid service providing both metadata and data management functionalities. In this way, along with near real-time processing of SAR images, we provide a data grid-oriented system for data storing, publishing, management, etc.