On tracing reactive systems

We present a rich and highly dynamic technique for analyzing, visualizing, and exploring the execution traces of reactive systems. The two inputs are a designer's inter-object scenario-based behavioral model, visually described using a UML2-compliant dialect of live sequence charts (LSC), and an execution trace of the system. Our method allows one to visualize, navigate through, and explore, the activation and progress of the scenarios as they "come to life" during execution. Thus, a concrete system's runtime is recorded and viewed through abstractions provided by behavioral models used for its design, tying the visualization and exploration of system execution traces to model-driven engineering. We support both event-based and real-time-based tracing, and use details-on-demand mechanisms, multi-scaling grids, and gradient coloring methods. Novel model exploration techniques include semantics-based navigation, filtering, and trace comparison. The ideas are implemented and tested in a prototype tool called the Tracer.