Performability of integrated software-hardware components of real-time parallel and distributed systems

A method for analyzing performability of the integrated software-hardware components of parallel and distributed systems is presented. The technique uses generalized stochastic Petri nets at the system level (analysis of integrated software-hardware systems). The intractable problem of evaluating a parallel software environment consisting of interacting fault-tolerant parallel tasks is addressed. This is accomplished using a decomposition technique at the task-graph level, where the task graph is decomposed into segments. Recovery blocks are effectively modeled in the interacting parallel modules as well as their supporting hardware. This method greatly facilitates the analysis of performability at the system level. However, the integrated performability model increases the size of the Markov generator matrix. This issue is addressed, and a performability decomposition technique at the task-graph level presented is illustrated by a simple example of a radar command center