Robert L. Clay

ASC ATDM Level 2 Milestone #5325: Asynchronous Many-Task Runtime System Analysis and Assessment for Next Generation Platforms.

This report provides in-depth information and analysis to help create a technical road map for developing nextgeneration programming models and runtime systems that support Advanced Simulation and Computing (ASC) workload requirements. The focus herein is on asynchronous many-task (AMT) model and runtime systems, which are of great interest in the context of “exascale” computing, as they hold the promise to address key issues associated with future extreme-scale computer architectures. This report includes a thorough qualitative and quantitative examination of three best-of-class AMT runtime systems—Charm++, Legion, and Uintah, all of which are in use as part of the ASC Predictive Science Academic Alliance Program II (PSAAP-II) Centers. The studies focus on each of the runtimes’ programmability, performance, and mutability. Through the experiments and analysis presented, several overarching findings emerge. From a performance perspective, AMT runtimes show tremendous potential for addressing extremescale challenges. Empirical studies show an AMT runtime can mitigate performance heterogeneity inherent to the machine itself and that Message Passing Interface (MPI) and AMT runtimes perform comparably under balanced conditions. From a programmability and mutability perspective however, none of the runtimes in this study are currently ready for use in developing production-ready Sandia ASC applications. The report concludes by recommending a codesign path forward, wherein application, programming model, and runtime system developers work together to define requirements and solutions. Such a requirements-driven co-design approach benefits the high-performance computing (HPC) community as a whole, with widespread community engagement mitigating risk for both application developers and runtime system developers.

Meta-component architecture for software interoperability

Most existing software is one-of-a-kind, monolithic, non-interoperable, and consequently, non-reusable. In addition, this software is difficult to maintain, improve, and scale. More importantly, this software is vital to many enterprises and institutions. Thus, enterprises must continuously make trade-off decisions between developing new software and maintaining existing software. The meta-component architecture (Component Mill) presented in the paper will enable enterprises to continue using existing software while providing a mechanism to migrate the software into a format (meta-component) that supports software integration and reuse. This architecture provides the blueprint for realizing an environment that supports exposing existing software for reuse with other (heterogeneous) software while allowing software development based on reuse. The metacomponents are independent of any component model used in component technologies. Thus, this architecture provides components that are, in principle, executable in any component technology.

SIENA Customer Problem Statement and Requirements

This document describes the problem domain and functional requirements of the SIENA framework. The software requirements and system architecture of SIENA are specified in separate documents (called SIENA Software Requirement Specification and SIENA Software Architecture, respectively). While currently this version of the document describes the problems and captures the requirements within the Analysis domain (concentrating on finite element models), it is our intention to subsequent y expand this document to describe problems and capture requirements from the Design and Manufacturing domains. In addition, SIENA is designed to be extendible to support and integrate elements from the other domains (see SIENA Software Architecture document).