Extending Binary Large Object Support to Open Grid Services Architecture-Data Access and Integration Middleware Client Toolkit

Abstract

Problem statement: OGSA-DAI middleware allows data resources to be federated and accessed via web services on the web or within grids or clouds. It provides a client API for writing programs that access the exposed databases. Migrating existing applications to the new technology and using a new API to access the data of DBMS with BLOB is difficult and discouraging. A JDBC Driver is a much convenient alternative to existing mechanism and provides an extension to OGSA-DAI middleware and allows applications to use databases exposed in a grid through the OGSA-DAI 3.0. However, the driver does not support Binary Large Objects (BLOB). Approach: The driver is enhanced to support BLOB using the OGSA-DAI Client API. It transforms the JDBC calls into an OGSA-DAI workflow request and sends it to the server using Web Services (WS). The client API of OGSA-DAI uses activities that are connected to form a workflow and executed using a pipeline. This workflow mechanism is embedded into the driver. The WS container dispatches the request to the OGSA-DAI middleware for processing and the result is then transformed back to an instance of ResultSet implementation using the OGSA-DAI Client API, before it is returned to the user. Results: Test on handling of BLOBs (images, flash files and videos) ranging from size 1 KB to size 2 GB were carried out on Oracle, MySQL and PostgreSQL databases using our enhanced JDBC driver and it performed well. Conclusion: The enhanced JDBC driver now can offer users, with no experience in Grid computing specifically on OGSA-DAI, the possibility to give their applications the ability to access databases exposed on the grid with minimal effort.