Model-driven Tools for Dependability Management in Component-based Distributed Systems

Emerging trends and challenges. Component-based software engineering supported by middleware technologies, such as CORBA Component Model (CCM) and Enterprise Java Beans (EJB), has emerged as a preferred way of developing enterprise distributed real-time and embedded (DRE) systems, such as smart buildings, modern office enterprises, and inflight entertainment systems. These systems consist of applications whose dependability requirements, such as availability and security, must be satisfied simultaneously to ensure dependable operation [1], [2]. For correct dependable operation of enterprise DRE systems, however, multiple dependability attributes must often be simultaneously satisfied. There are inherent challenges in satisfying multiple dependability attributes together due to tradeoffs and conflicts between them. For example, deploying replicas of a service on hosts that are unauthorized to access by clients may result in unavailability of the service to its clients on failure of another replica of the same service. It is hard to detect and analyze these errors at runtime, which motivates the need to catch as many errors at design-time as possible. Hence, there is a need for design-time tools to reason about the inherent tradeoffs and conflicts between multiple dependability attributes and alleviate complexities in developing dependable enterprise DRE systems. Figure 1 depicts desirable properties of a design-time tool that considers multiple dependability attributes (such as availability and security) to reason about system dependability e.g., protecting it from various hazards (such as faults and unauthorized access).