OGSA-DAI: Two Years On

The OGSA-DAI project has been producing Grid-enabled middleware for almost two years now, providing data access and integration capabilities to data resources, such as databases, within an OGSA context. In these two years, OGSA-DAI has been tracking rapidly evolving standards, managing changes in software dependencies, contributing to the standardisation process and liasing with a growing user community together with their associated data requirements. This process has imparted important lessons and raised a number of issues that need to be addressed if a middleware product is to be widely adopted. This paper examines the experiences of OGSA-DAI in implementing proposed standards, the likely impact that the still-evolving standards landscape will have on future implementations and how these affect uptake of the software. The paper also examines the gathering of requirements from and engagement with the Grid community, the difficulties of defining a process for the management and publishing of metadata, and whether relevant standards can be implemented in an efficient manner. The OGSA-DAI software distribution and more details about the project are available from the project Web site at http://www.ogsadai.org.uk/.