Remote Data Repository Access - Integration of OGSA-DAI™ into the SIMDAT Integrated Grid Infrastructure
The remote data repository access components provide services for the access and manipulation of data repositories with the GRIA‑based SIMDAT Grid infrastructure. They are derived from the OGSA-DAI™ system as developed by the University of Edinburgh, and support a wide variety of data repositories (file systems, many relational and XML databases) and delivery mechanisms (including transmission as SOAP attachment, ftp, http, email).

Technical contributions by SIMDAT
SIMDAT has focused on providing a seamless integration of OGSA‑DAI with the GRIA‑based Grid infrastructure, enabling users and applications to open or remove a data repository, gain access rights as user or administrator, and request data access operations by way of an OGSA-DAI™ perform document from within GRIA. This approach leverages GRIA’s built‑in authentication and process‑based authorization capabilities.

Based on OGSA‑DAI framework, the adaptors for the Semantic Bus that underpins the Automotive Semantic Mediation prototype have been created. Technically, they are new OGSA‑DAI activities that abstract from whether a CAE/CAD application accesses a local database that matches its own data model/representation, or goes through a number of Semantic Mediation steps to access a remote repository controlled by a foreign application.
Feedback from SIMDAT as to functionality required (such as fine‑grained access control) and performance problems experienced (which were a real problem with earlier OGSA‑DAI releases) have been instrumental to guide the improvement of OGSA‑DAI in recent years.

The GRIA OGSA-DAI™ service code that provides the integration of both is available for free and under the LGPL Open Source license (www.gnu.org/licenses/lgpl.html) from www.gria.org. OGSA‑DAI itself is available for free under a special OGSA‑DAI license (www.ogsadai.org/downloads/licence.php) from www.ogsadai.org. Registration is required prior to being allowed to download.

Michael Krueger