Composing and executing parallel data-flow graphs with shell pipes

In this paper we extend the concept of shell pipes to incorporate forks, joins, cycles, and key-value aggregation. These extensions enable the implementation of a class of data-flow computation with strong deterministic properties, and provide a simple yet powerful coordination layer for leveraging multi-language and legacy components for large-scale parallel computation. Concretely, this paper describes the design and implementation of the language extensions in Bourne Again SHell (BASH), and examines the performance of the system using micro and macro benchmarks. The implemented system is shown to scale to thousands of processors, enabling high throughput performance for millions of processing tasks on large commodity compute clusters.