Build Grid Enabled Scientific Workflows Using gRAVI and Taverna

Scientific communities are increasingly exposing information and tools as online services in an effort to abstract complex scientific processes and large data sets. Clients are then able to access services without knowledge of their internal workings therefore simplifying the process of replicating scientific research. Taking a service-oriented approach to science (SOS) facilitates reuse, extension, and scalability of components, whist also making information and tools available to a wider audience. Scientific workflows play a key role in realizing SOS by orchestrating services into well formed logical pipelines created to model the requirements of complex scientific experiments. The task of developing such service-oriented infrastructures is not trivial as developers must create and deploy Web services and then coordinate multiple services into workflows. This paper presents an end-to-end approach for developing SOS-based workflows with the aim of simplifying development, deployment, and execution. In particular, we use gRAVI to wrap applications as WSRF Web services and Taverna to compose and execute workflows. The process is validated through the creation of a real world bioinformatics workflow involving multiple services and complex execution paths.