The next frontier: interactive and closed loop performance steering

Software for a growing number of problem domains has complex, time varying behavior and unpredictable resource demands (e.g., WWW servers and parallel input/output systems). While current performance analysis tools provide insights into application dynamics and the causes of poor performance, with a posteriori analysis one cannot adapt to temporally varying application resource demands and system responses. We believe that the solution to this performance optimization conundrum is integration of dynamic performance instrumentation and on-the-fly performance data reduction with real-time adaptive control mechanisms that select and configure resource management algorithms automatically, based on observed application behavior, or interactively, through high-modality virtual environments. We motivate this belief by first describing our experiences with performance analysis tools, input/output characterization, and WWW server analysis, and then sketching the design of interactive and closed loop adaptive control systems.