Interacting with scientific workflows

Abstract

Scientific workflow technology has become a de facto standard in e-Science. It provides a powerful unifying platform that allows scientists to build arbitrarily complicated applications by combining predefined components. With a wide range of components, with the functions ranging from acquiring data inputs from sensors, querying databases, performing data-mining, performing execution, through to visualising the results, this paradigm allows scientists to automate, manage and execute various steps in scientific research. Although powerful, scientific workflow systems still require some programming knowledge, which might not be optimal for many scientists.Recently, scientific workflows have been integrated into the Web, creating workflow-based science gateways. These gateways allow scientists to launch large-scale computational experiments without concern for the underlying complexity of the infrastructure. This approach delivers scientific workflows to more scientists and is becoming increasingly popular.To date, much workflow-based science gateway development effort has been invested in creating user-friendly and secure interfaces to setup parameters, execute workflows and collect results.However, interaction between users and executing workflows has not received a lot of attention.Scientific workflows have typically been executed in batch mode. This model does not work with human-in-the-loop workflows, which require continuous interaction between users and executing workflows.A fundamental contribution of this thesis is to show that gateways can support complex humanworkflow interactions, facilitating monitoring and steering of the workflow execution as it progresses. This is important because scientific workflows increasingly require user decisions and interactions at various steps; human decision-making is an important component of real-world computational science. In order to achieve this goal, the thesis presents the design, implementation and demonstration of WorkWays, an interactive workflow-based science gateway for supporting development and execution of human-in-the-loop scientific workflows. WorkWays consists of two distinct frameworks with well defined APIs and bindings: a framework that enables humanworkflow interaction and a framework for workflow development and execution.iii I acknowledge that an electronic copy of my thesis must be lodged with the University Library and, subject to the policy and procedures of The University of Queensland, the thesis be made available for research and study in accordance with the Copyright Act 1968 unless a period of embargo has been approved by the Dean of the Graduate School.I acknowledge that copyright of all material contained in my thesis resides with the copyright holder(s) of that material. Where appropriate I have obtained copyright permission from the copyright holder to reproduce material in this thesis.