Validation of Fault-Free Behavior of a Reliable Multiprocessor System FTMP: A Case Study

The Fault Tolerant Multi-Processor (FTMP) was designed as a highly survivable avionics system. It has been simulated, modeled and emulated extensively for several years. A prototype has been constructed and delivered to the Avionics integrated Research Laboratory (AIRLAB) at NASA/Langley Research Center. This report summarizes the analysis of several baseline experiments. These experiments were part of a methodology designed to test and verify the fault-free performance of the system at many levels, from hardware through system software. The experiments, while simple, were fundamental to understanding how to measure FTMP performance. From the experiments it was determined that the clock is a valid time measurement device in the tested cases; that instruction execution times are virtually constant; that the R4 frame size is 40mS with some variation; that the frame stretching mechanism has some flaws in its implementation that allow the possibility of a frame stretching infinitely. Future measurements are planned. Some will broaden the results of these initial experiments. Others will measure the system more dynamically. This includes the implementation of a synthetic workload generation mechanism on FTMP.