A rule-based platform for distributed real-time SOA with application in defence systems

Modularity has been a key issue in the design and development of modern embedded Real-Time Software Systems (RTS), where modularity enables flexibility with respect to changes in platform, environment, and requirements, as well as reuse. In distributed RTS, similar ideas have led to the adoption of COTS components integrated via Service-Oriented Architecture (SOA) principles and technologies that are already well-established in business-oriented information systems. However, current SOA implementations, with respect to service activation and orchestration, do not meet strict time-dependent constraints on scalability and latency required by RTS. We present a novel approach to RTS development where the orchestration of real-time processes is distributed among the services within a fully distributed data-driven process framework. Our framework wraps around COTS components implementing individual processing steps in a distributed real-time process. Our execution model is configurable through message routing policies distributed as a knowledge base containing rule sets, thus maintaining real-time constraints, and therefore dispenses with the need for a central orchestration component which could easily become a bottleneck. Deterministic behaviour can therefore be achieved through the validation of the rule-sets and the use of Modular Performance Analysis.