Grid Service Composition in BPEL for Scientific Applications

Abstract

Abstract. Grid computing aims to create an accessible virtual supercomputer by integrating distributed computers to form a parallel infrastructure for processing applications. To enable service-oriented Grid computing, the Grid computing architecture was aligned with the current Web service technologies; thereby, making it possible for Grid applications to be exposed as Web services. The WSRF set of specifications standardized the association of state information with Web services (WSResource) while providing interfaces for the management of state data. Key to the realization of the benefits of Grid computing is the ability to integrate WS-Resources to create higher-level applications. The Business Process Execution Language (BPEL) is the leading standard for integrating Web services and as such has a natural affinity to the integration of Grid services. In this paper, we share our experience on using BPEL to integrate, create, and manage WS-Resources that implement the factory pattern. We use a Bioinformatics application as a case study to show how BPEL can be used to orchestrate Grid services. The execution environment for our case study comprises the Globus Toolkit as the Grid middleware and the ActiveBPEL as the BPEL engine. To the best of our knowledge, this work is among the handful approaches that successfully use BPEL for orchestrating WSRF-based services and the only one that includes the discovery and management of instances.

SEPL—a domain-specific language and execution environment for protocols of stateful Web services

“…WSCL does not take WSRF into account, and also WS-BPEL has no direct support for WSRF, which has been addressed in previous works [8,12].…”

“…Unfortunately, WS-BPEL falls short of supporting stateful service resources, especially their creation using factories, in an appropriate way. [8,12] state that WS-BPEL does not define a standard way to store the resource identifier returned by a factory service and automatically use it in subsequent invocations on the created resource. In [8] a WSRF-specific gridInvoke operation is suggested to overcome this issue.…”

Fine-Grain Interoperability of Scientific Workflows in Distributed Computing Infrastructures

“…By using the name of the corresponding ports in the placeholder (i.e. <PLACEHOLDER FILESERVER in1/> instead of the URL in line 14) we are able to establish the required logical connection to the information contained in the IWIR abstract task type signature.…”

Grid-enabled Spatial Data Infrastructure for environmental sciences: Challenges and opportunities

“…It uses WSDL as component model and XML as data model [29]. Despite the fact that Kepler, SciFlo and Taverna are engines natively designed to support Grid services, recent studies [54][55][56] applied a successful approach, using the Web Service Resource Framework (WSRF), to extend BPEL capabilities to orchestrate Grid and non-Grid services. This appears to be a promising approach to orchestrate OGC services and Grid services [57,58].…”