Armada Middleware and Communication Services

Abstract

Real-time embedded systems have evolved during the past several decades from small customdesigned digital hardware to large distributed processing systems. As these systems become more complex, their interoperability, evolvability and cost-effectiveness requirements motivate the use of commercial-off-theshelf components. This raises the challenge of constructing dependable and predictable real-time services for application developers on top of the inexpensive hardware and software components which has minimal support for timeliness and dependability guarantees. We are addressing this challenge in the ARMADA project.ARMADA is set of communication and middleware services that provide support for fault-tolerance and end-toend guarantees for embedded real-time distributed applications. Since real-time performance of such applications depends heavily on the communication subsystem, the first thrust of the project is to develop a predictable communication service and architecture to ensure QoS-sensitive message delivery. Fault-tolerance is of paramount importance to embedded safety-critical systems. In its second thrust, ARMADA aims to offload the complexity of developing fault-tolerant applications from the application programmer by focusing on a collection of modular, composable middleware for fault-tolerant group communication and replication under timing constraints. Finally, we develop tools for testing and validating the behavior of our services. We give an overview of the ARMADA project, describing the architecture and presenting its implementation status.

Real-time communication and coordination in embedded sensor networks

“…Most prior membership and group communication services assume reasonably static systems [3], [18], [44]. Group members in such systems do not have a high turnaround rate.…”

Pattern-Based Composition and Analysis of Virtually Synchronized Real-Time Distributed Systems

“…These synchronization techniques however do not satisfy hard real-time guarantees. Real-time versions of these communication services have been proposed in [10] [11]. Although very useful in many contexts, these works are more suitable to synchronize replicated state machines (which commonly execute in the same rate).…”

MEAD: support for Real‐Time Fault‐Tolerant CORBA

“…ARMADA [21] is a set of communication and middleware services that provide support for fault tolerance and end-to-end guarantees for embedded real-time distributed applications. The two distinct aspects of this project include the development of a predictable communication service for QoSsensitive message delivery.…”