A rule-based component parameterization technique for QoS trade-off reconfiguration.

摘要

Realizing the quality of service (QoS) requirements for an embedded software system continues to be a challenging issue in component based software engineering. The QoS capabilities of an embedded system are affected by the QoS capabilities of its components. Hence, it is necessary that the QoS capabilities of the components are predictable and reconfigurable. Unfortunately, the QoS capabilities of many components are not predictable since the QoS data of these components are not available. Furthermore, many components are not designed to be reconfigurable in terms of QoS capabilities. It is often labor-intensive and error prone work to reconfigure the components. The work also requires experienced, senior developers, which makes it costly.; The lack of predictability and reconfigurability in existing components motivates the development of a rule-based component parameterization technique that supports the automatic reconfiguration of components to achieve QoS trade-offs. The component parameterization technique is the first approach that adopts the rule-based paradigm to parameterize components for QoS trade-off adaptation. In addition, the component parameterization technique provides a QoS data collection approach that supports the automatic measurement of components' QoS capabilities.; The effectiveness and performance of the component parameterization technique is validated using two libraries of components. The results show that the technique is effective and scalable. The F-measure results (i.e., the weighted harmonic mean of precision and recall) for the validation are excellent: 94%. The QoS data collection approach is also validated using the same two libraries of components. QoS data (time, space, and quality) on three platforms including Windows, Unix and PDA are collected.; An example application for PDA devices is developed to demonstrate the application of the component parameterization technique to develop embedded software. Components that are used to develop the application are parameterized and reconfigured to ensure that the integrated application meets the QoS requirements for the target PDA device.; Two additional sets of rules (one rule set achieves component optimizations and the other rule set achieves the coding standard conformance validation) are also developed to demonstrate the extensibility of the component parameterization technique.