DEBUGGING HETEROGENEOUS DISTRIBUTED SYSTEMS USING EVENT-BASED MODELS OF BEHAVIOR

We describe a high-level debugging approach, Event-Based Behavioral Ab straction (EBBA), in which debugging is treated as a process of creati ng models of expected program behaviors and comparing these to the act ual behaviors exhibited by the program. The use of EBBA techniques can enhance debugging-tool transparency, reduce latency and uncertainty f or fundamental debugging activities, and accommodate diverse, heteroge neous architectures. Using events and behavior models as a basic mecha nism provides a uniform view of heterogeneous systems and enables anal ysis to be performed in well-defined ways. Their use also enables EBBA users to extend and reuse knowledge gained in solving previous proble ms to new situations. We describe our behavior-modeling algorithm that matches actual behavior to models and automates many behavior analysi s steps. The algorithm matches behavior in as many ways as possible an d resolves these to return the best match to the user. It deals readil y with partial behavior matches and incomplete information. In particu lar, we describe a tool set we have built. The tool set has been used to investigate the behavior of a wide range of programs. The tools are modular and can be distributed readily throughout a system.