Performance Trees: A Query Specification Formalism for Quantitative Performance Analysis

摘要

Finding a way to specify complex performance queries on models of systems in a way that is both accessible and expressive is a major challenge in performance analysis. This paper describes our attempts to address this challenge through the development of performance trees, a formalism for the graphical specification of complex performance queries on stochastic models. Performance trees are designed to be accessible by providing more intuitive query specification, expressive by being able to reason about a broader range of concepts than current alternatives, extensible by supporting additional user-defined concepts, and versatile through their applicability to multiple modelling formalisms. Tool support is implemented in the form of a module for the PIPE2 Petri net tool, which provides performance tree query design capabilities through both a graphical user interface and a natural language query builder. Query evaluation is supported by a set of integrated parallel and distributed analysis tools, which are hosted on a dedicated cluster. The application of performance trees is demonstrated in the context of a case study of an online transaction system. We also illustrate their flexibility with extensions that permit the specification and monitoring of service level agreements.