Architectures and Patterns for Developing High-performance, Real-time ORB Endsystems

Abstract

Abstract Many types of applications can benefit from flexible and open middleware. CORBA is an emerging middleware standard for Object Request Brokers (ORBs) that simplifies the development of distributed applications and services. Experience with CORBA demonstrates that it is suitable for traditional RPC-style applications. However, the lack of performance optimizations and quality of service (QoS) features in conventional CORBA implementations make them unsuited for high-performance and real-time applications. This paper makes four contributions to the design of CORBA ORBs for applications with high-performance and real-time requirements. First, it describes the design of TAO, which is our high-performance, real-time CORBA-compliant ORB. Second, it presents TAO’s real-time scheduling service, which provides QoS guarantees for deterministic real-time CORBA applications. Third, it empirically evaluates the effects of priority inversion and non-determinism in conventional ORBs and shows how these hazards are avoided in TAO. Fourth, it presents a case study of key patterns used to develop TAO and quantifies the impact of applying patterns to reduce the complexity of common ORB tasks.