Providing Dynamic Virtualized Access to Grid Resources via the Web 2.0 Paradigm

Grid systems provide mechanisms for single sign-on, and uniform APIs for job submission and data transfer, in order to allow the coupling of distributed resources in a seamless manner. However, new users face a daunting barrier of entry due to the high cost of deployment and maintenance. They are often required to learn complex concepts relative to grid infrastructures (credential management, scheduling systems, data staging, etc). To most scientific users, running their applications with minimal changes and yet getting results faster is highly desirable, without having to know much about how the resources are used. Hence, a higher level of abstraction must be provided for the underlying infrastructure to be used effectively. For this purpose, as part of our prior work, we have developed the Opal toolkit for exposing applications on grid resources as simple Web services [1]. Opal provides a basic set of APIs that allows users to execute their deployed applications through graphical user interfaces, or via programmatic means. In this paper, we present our ongoing work to extend the Opal toolkit that enables the creation of an end-to-end infrastructure to dynamically leverage scientific applications on grid resources. In particular, we focus on the following two key extensions. We have developed a command-line syntax description language that can be published via the Opal interface. This enables the creation of dynamic Web forms for job submission, and may even be used for creating familiar application-specific user interfaces in other types of Problem Solving Environments (PSE). Additionally, we have extended the Community Scheduler Framework (CSF4) Meta-scheduler to support the concept of applications as first class resources. This enables Opal to submit jobs to different grid resources where an application is deployed without affecting how user applications interact with Opal. We believe that these extensions enable the Opal toolkit to effectively leverage multiple grid resources, and provide access to the users in a transparent Web 2.0 fashion.