User Friendly Management of Workflow Results: From Provenance Information to Grid Logical File Names

Grid workflows can produce thousands of results that should be properly organised to enable further analysis. Typically results are stored on locations hard-coded in the workflow or in the components, limiting reusability. In this paper we present an approach to (re)organise the output files generated by a grid workflow in a distributed storage environment. We propose to perform a post-mortem mapping of workflow results into a directory structure. This mapping is based on data provenance information and exploits grid catalog features, namely logical file names, to avoid data replication. By defining different mappings, users can generate their own semantic view of results generated during a workflow execution, which fosters user-friendliness, whereas preserving workflow reusability. An implementation on the Virtual Resource Browser (VBrowser) framework is detailed and evaluated on neuroimaging workflows. Results show that the complex directory structure of an image analysis application cane properly generated by our system. An initial performance evaluation of the mapping resolution and directory structure creation indicates that this approach provides a practical, simple, yet powerful solution to an important roadblock for the adoption of workflows to implement complex image analysis pipelines.