Biblio

Conference and journal publications increasingly require experiments associated with a submitted article to be repeatable. Authors comply to this requirement by sharing all associated digital artifacts, i.e., code, data, and environment configuration scripts. To ease aggregation of the digital artifacts, several tools have recently emerged that automate the aggregation of digital artifacts by auditing an experiment execution and building a portable container of code, data, and environment. However, current tools only package non-distributed computational experiments. Distributed computational experiments must either be packaged manually or supplemented with sufficient documentation. In this paper, we outline the reproducibility requirements of distributed experiments using a distributed computational science experiment involving use of message-passing interface (MPI), and propose a general method for auditing and repeating distributed experiments. Using Sciunit we show how this method can be implemented. We validate our method with initial experiments showing application re-execution runtime can be improved by 63% with a trade-off of longer run-time on initial audit execution.

Science is conducted collaboratively, often requiring knowledge sharing about computational experiments. When experiments include only datasets, they can be shared using Uniform Resource Identifiers (URIs) or Digital Object Identifiers (DOIs). An experiment, however, seldom includes only datasets, but more often includes software, its past execution, provenance, and associated documentation. The Research Object has recently emerged as a comprehensive and systematic method for aggregation and identification of diverse elements of computational experiments. While a necessary method, mere aggregation is not sufficient for the sharing of computational experiments. Other users must be able to easily recompute on these shared research objects. In this paper, we present the sciunit, a reusable research object in which aggregated content is recomputable. We describe a Git-like client that efficiently creates, stores, and repeats sciunits. We show through analysis that sciunits repeat computational experiments with minimal storage and processing overhead. Finally, we provide an overview of sharing and reproducible cyberinfrastructure based on sciunits gaining adoption in the domain of geosciences.