Zero-Sided Communication Challenges in Implementing Time-Based Channels using the MPI/RT Specification

Distributed real-time applications require support from the underlying middleware to meet the strict requirements for jitter, latency, and bandwidth. While most existing middleware standards such as MPI do not support Quality of Service (QoS), the MPI/RT standard supports QoS in addition to striving for high performance. This thesis presents HARE, the first known implementation of a subset of the MPI/RT 1.1 standard with time-driven QoS support. This thesis proves the following hypothesis: It is possible to achieve zero-sided communication (a model of communication characterized by the absence of any explicit per-message transfer calls by any of the participating sides) in a real-time environment using a QoS contract between an application and message-passing middleware. Furthermore, it is shown that the performance and predictability of a time-driven task using zero-sided communication is better than that of a best-effort task. The hypothesis is validated through compact MPI/RT application programs that achieve zero-sided communication

MPI/FT TM: Architecture and Taxonomies for Fault-Tolerant, Message-Passing Middleware for Performance-Portable Parallel Computing *Work performed in part with support from NASA under

MPI has proven effective for parallel applications in situations with neither QoS nor fault handling. Emerging environments motivate fault-tolerant MPI middleware. Environments include space-based, wide-area/web/meta computing, and scalable clusters. MPI/FT, the system described here, trades off sufficient MPI fault coverage against acceptable parallel performance, based on mission requirements and constraints. MPI codes are evolved to use MPI/FT features. Non-portable code for event handlers and recovery management is isolated