International Journal of Parallel and Distributed Networks and Systems 1 Consistency Considerations in the Interactive Steering of Computations

| Interactive steering can be helpful in understanding and managing parallel and distributed systems. Multiple approaches to the implementation of steering systems are under investigation or in development. However, the notion of consistency in both the presentation of system state and the application of steering changes to the executing system varies considerably from system to system. We present these various approaches to steering and to consistency and discuss their costs and beneets. Also, we present PathFinder, a general architecture for monitoring and steering that permits users to conngure the steering system to provide varying levels of consistency and that supports highly dynamic and expressive speciication of steering actions. PAT(PathFinder: Agents/Transaction), our initial implementation of the PathFinder architecture, employs agent-based monitoring and steering coupled with transaction-based consistency calculations. The exibility of this agent-based approach is amenable to experimentation with a variety of consistency conditions.