Scientific Workflows as Services in caGrid: A Taverna and gRAVI Approach

In scientific collaboration platforms such as caGrid, workflow-as-a-service is a useful concept for various reasons, such as easy reuse of workflows, access to remote resources, security concerns, and improved execution performance. We propose a solution for facilitating workflow-as-a-service based on Taverna as the workflow engine and gRAVI as a service wrapping tool. We provide both a generic service to execute all Taverna workflows, and an easy-to-use tool (gRAVI-t) for users to wrap their workflows as workflow-specific services, without developing service code. The signature of the specific service is identical to the corresponding workflow´s input/output definition and is therefore more self-explained to workflow users. These two categories of services are useful in different scenarios, respectively. We use a tumor analysis workflow as an example to demonstrate how the workflow-as-a-service approach benefits the execution performance. Finally a conclusion is drawn and future research opportunities are discussed.