The BPEL orchestrating framework for secured grid services

Workflow has been considered as a crucial component in several Grid projects. Among many workflow standards, BPEL, Business Process Execution Language, is emerging as a de-facto workflow standard in Grid and Web services communities. In this paper, we present the adoption of standard BPEL to orchestrate Grid services based on OGSI specification. Our approach is based on proxy services, which enable user to interact with OGSI Grid services supporting GSI security mechanisms, OGSI factory mechanism, and notification mechanism. Our proposed architecture is platform-neutral as it does not depend on any specific security architecture. With our implementation, the proxy services witl be generated automatically for each target Grid service. Thus, they are not limited to pre-defined Grid services. In addition, our proxy services also remove design-time binding limitations of BPEL and allow user to define the binding information of proxy services in run-time. As our approach utilizes original BPEL specification without special modification, we believe that developing Grid applications on our architecture will benefit from standard BPEL-compliant tools and generic Web services tools. We illustrate the example of using our proposed framework by orchestrating drug discovery processes using BPEL and Grid services.