Composition of Message Passing Applications On-Demand

Ensemble has been proposed as a methodology for designing and implementing message passing applications by composition of modular and reusable message passing components. In this paper we adapt Ensemble as a mechanism for composing message passing applications in a meta-computing context on demand. Ensemble is particularly effective in the case where users demand different process topologies to be created out of the same components. We demonstrate this case by an application from transaction processing and in particular parallel query execution based on the tree pipelining model.