Customizing Dependability with Reusable Software Components

Many large software systems have diierent components with varying requirements for robustness and performance. Moreover, dependability requirements often change throughout their software life-cycle. Thus any single dependability technique is insuf-cient for implementing large systems. Software developers need to be able to modify dependability code without modifying application code. We outline a methodology for the separate development and maintenance of dependability and application codes. The advantage of our methodology is that dependability of each component may be customized and the dependability techniques reused with diierent application components. We demonstrate that our approach may be implemented eeciently, providing comparable performance to applications with hand-coded dependable behavior. We discuss a run-time system to implement our techniques and some optimizations it uses.