Compositional layered performance modeling of peer-to-peer routing software

Models can help to understand the performance aspects of a computer system from the software architecture and its configurations, but ease of model creation is critical. A compositional model-building approach is described here, in which component submodels are generated from the scenarios they participate in. Submodel classes are derived from an analysis of behaviour patterns as the scenarios traverse the software components. Then submodels are instantiated and combined in the overall system model. The approach is particularly effective in peer-to-peer systems in which subsystems inherit most of their behaviour from a few shared patterns, termed "behaviour-inheriting peer" (BIP) systems. A model-building algorithm is described, and is demonstrated on a prototype emulator for a network of routers. The emulator, called CGNet, can be configured for its deployment and for traffic patterns and routes. An automatic model-generator uses this information to build a model which represents the overall system configuration. The approach is quite general and can be used to model component-based systems in which the components themselves are created in many configurations.