Technical Report Number
A key challenge for distributed real-time and embedded (DRE) middleware is maintaining both system reliability and desired real-time performance in unpredictable envi-ronments where system workload and resources may ﬂuc-tuate signiﬁcantly. This paper presents FC-ORB, a real-time Object Request Broker (ORB) middleware that em-ploys end-to-end utilization control to handle ﬂuctuations in application workload and system resources. The contribu-tions of this paper are three-fold. First, we present a novel utilization control service that enforces desired CPU utiliza-tion 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 re-sults demonstrate that our middleware can maintain desired utilizations in face of uncertainties and variations in task execution times, resource contentions from external work-loads, and permanent processor failure. FC-ORB demon-strates that the integration of utilization control, end-to-end scheduling and fault-tolerance mechanisms in DRE middle-ware is a promising approach for enhancing the robustness of DRE applications in unpredictable environments.
Wang, Xiaorui; Lu, Chenyang; and Koutsoukos, Xenofon, "Enhancing the Robustness of Distributed Real-Time Middleware via End-to-End Utilization Control" Report Number: WUCSE-2005-45 (2005). All Computer Science and Engineering Research.