Modeling and Evaluation of Paradyn Instrumentation System

This paper models and evaluates the overheads of data collection components and services (called an instrumentation system) of Paradyn Parallel Performance Tools. An instrumentation system (IS) is an integral part of any measurementbased parallel tool to collect runtime information from concurrent processes. However, software instrumentation is known to be intrusive and likely to change the behavior of application programs. Additionally, the instrumentation system is a part of the enabling technology of the tool and hence removed from the end-user. Therefore, it is important to evaluate its overheads at an early stage of tool development. We develop and parameterize a resource occupancy (ROCC) model for Paradyn IS on an IBM SP-2 platform. This model is validated with measurements and subsequently used to answer several “what if” questions regarding various configuration options and management policies for the instrumentation system and their impact on overheads to the application processes. We also summarize the results of this evaluation as recommendations to the IS developers.