A Feedback Controlled-ORB Middleware to Enhance the Robustness of Distributed Real-Time Middleware via End-to-End Utilization Control

A key challenge for distributed real-time and embedded (DRE) middleware is maintaining both system reliability and desired real-time performance in unpredictable environments where system workload and resources may fluctuate significantly. This paper presents FC-ORB, a real-time Object Request Broker (ORB) middleware that employs end-to-end utilization control to handle fluctuations in application workload and system resources. The contributions of this paper are three-fold. First, we present a novel utilization control service that enforces desired CPU utilization bounds on multiple processors by adapting the rates of end-to-end tasks within user-specified ranges. Second, we describe a set of middleware-level mechanisms designed to support end-to-end tasks and distributed multi-processor utilization control in a real-time ORB. Finally, we present extensive experimental results on a Linux testbed. Our results demonstrate that our middleware can maintain desired utilizations in face of uncertainties and variations in task execution times, resource contentions from external workloads, and permanent processor failure. FC-ORB demonstrates that the integration of utilization control, end-to-end scheduling and fault-tolerance mechanisms in DRE middleware is a promising approach for enhancing the robustness of DRE applications in unpredictable environments.

FC-ORB is implemented based on previous work, FCS-nORB and nORB.

Xiaorui Wang, Yingming Chen, Chenyang Lu, and Xenofon Koutsoukos, ”FC-ORB: A Robust Distributed Real-time Embedded Middleware with End-to-End Utilization Control”, to appear in the Elsevier Journal of Systems and Software, Special Issue on Dynamic Resource Management in Distributed Real-Time Systems.

Xiaorui Wang, Chenyang Lu, and Xenofon Koutsoukos, Enhancing the Robustness of Distributed Real-Time Middleware via End-to-End Utilization Control, The 26th IEEE Real-Time Systems Symposium (RTSS 2005), Miami, Florida, December 2005.


FC-ORB is open-source software. You are welcome to download the current release of FC-ORB 1.0:

To install FC-ORB, you need to


For more information, please contact Prof. Xiaorui Wang. This project is a joint work with Prof. Chenyang Lu and Prof. Xenofon Koutsoukos.

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