A-GWL: Abstract Grid Workflow Language

Abstract

Abstract. Grid workflow applications are emerging as one of the most interesting application classes for the Grid. In this paper we present A-GWL, a novel Grid workflow language to describe the workflow of Grid applications at a high level of abstraction. A-GWL has been designed to allow the user to concentrate on describing scientific Grid applications. The user is shielded from details of the underlying Grid infrastructure. A-GWL is XML-based which defines a graph of activities that refers to computational tasks or user interactions. Activities are connected by controland data-flow links. We have defined A-GWL to support the user in orchestrating Grid workflow applications through a rich set of constructs including sequence of activities, sub-activities, control-flow mechanisms (sequential flow, exclusive choice, and sequential loops), data-flow mechanisms (input/output ports), and data repositories. Moreover, our work differs from most existing Grid workflow languages by advanced workflow constructs such as parallel execution of activities with pre-and postconditions, parallel loops, event-based synchronization mechanisms, and property-based selection of activities. In addition, the user can specify high-level constraints and properties for activities and data-flow links.

Applying BPEL to Chemical Research on Grid

“…Moreover, Abstract Grid Workflow Language (AGWL) [22] in Askalon and the Grid Workflow Description Language (GWorkflowDL [23]) in CoreGRID as grid-oriented workflow languages both allow the user to concentrate on describing Grid applications in Scientific Workflow. A number of workflow languages have already been used to describe the scientific workflow.…”

Ontology-Driven Composition and Validation of Scientific Grid Workflows in Kepler: a Case Study of Hyperspectral Image Processing

“…Apart from using business workflow languages (e.g., BPEL4WS and its predecessors) directly for Grid applications (e.g., [7]), quite a few Grid workflow languages have been proposed, such as Grid Services Flow Language (GSFL, [8]), Grid Application Definition Language (GADL, [9]), Grid Workflow Execution Language (GWEL, [10]) and Grid Services Workflow Execution Language (GSWEL, [11]), GridAnt [12], Abstract Grid Workflow Language (AGWL, [13] [14]). For those that are based on business workflow languages (e.g., GWEL and GSWEL), generic business workflow composition environments may be extended to compose Grid workflows.…”

A Framework for Advanced Modularization and Data Flow in Workflow Systems

“…The Abstract Grid Workflow Language (AGWL) [14] is an interesting approach which also identifies the need for an powerful, separate data perspective. However, the approach does not address the requirement of separation of concerns.…”

“…However, existing workflow research [13,14] has shown that having only a single workflow perspective is insufficient. Nevertheless, the data perspective of our approach can be seen as a coarse grained data flow language where tasks are the macro actors.…”