Performance specification of software components

Abstract

Component-based software engineering is concerned with predictability in both functional and performance behavior, though most formal techniques have typically focused their attention on the former. Reasoning about the (functional or performance) behavior of a component-based system must be compositional in order to be scalable. Compositional performance reasoning demands that components include performance specifications, in addition to descriptions of functional behavior. Unfortunately, as explained in this paper, classical techniques and notations for performance analysis are either unsuitable or unnatural to capture performance behaviors of generic software components. They fail to work in the presence of parameterization and layering. The paper introduces elements of a compositional approach to performance analysis using a detailed example. It explains that performance specification problems are so basic that there are unresolved research issues to be tackled even for the simplest reusable components. These issues must be tackled by any practical proposal for sound performance reasoning. Only then will software developers be able to engineer new systems by choosing and assembling components that best fit their performance (time and space) requirements.