The Component Architecture of Open MPI: Enabling Third-Party Collective Algorithms*

As large-scale clusters become more distributed and heterogeneous, significant research interest has emerged in optimizing MPI collective operations because of the performance gains that can be realized. However, researchers wishing to develop new algorithms for MPI collective operations are typically faced with significant design, implementation, and logistical challenges. To address a number of needs in the MPI research community, Open MPI has been developed, a new MPI-2 implementation centered around a lightweight component architecture that provides a set of component frameworks for realizing collective algorithms, point-to-point communication, and other aspects of MPI implementations. In this chapter, we focus on the collective algorithm component framework. The “coll” framework provides tools for researchers to easily design, implement, and experiment with new collective algorithms in the context of a production-quality MPI. Performance results with basic collective operations demonstrate that the component architecture of Open MPI does not introduce any performance penalty.