Technical Report Number
The advent of open and widely adopted standards such as Common Object Request Broker Architecture (CORBA)  has simpliﬁed and standardized the development of distributed applications. For applications with real-time constraints, including avionics, manufacturing, and defense systems, these standards are evolving to include Quality-of-Service (QoS) speciﬁcations. Operating systems such as Real-time Linux  have responded with interfaces and algorithms to guarantee real-time response; similarly, languages such as Real-time Java  include mechanisms for specifying real-time properties for threads. However, the middleware upon which large distributed applications are based has not yet addressed end-to-end guarantees of QoS speciﬁcations. Unless this challenge can be met, developers must resort to ad hoc solutions that may not scale or migrate well among different platforms. This thesis provides two contributions to the study of real-time Distributed Object Computing (DOC) middleware. First, it identiﬁes potential bottlenecks and problems with respect to guaranteeing real-time performance in contemporary middleware. Experimental results illustrate how these problems lead to incorrect real-time behavior in contemporary middleware platforms. Second, this thesis presents designs and techniques for providing real-time QoS guarantees in DOC middleware in the context of TAO , an open-source and widely adopted implementation of real-time CORBA. Architectural solutions presented here are coupled with empirical evaluations of end-to-end real-time behavior. Analysis of the problems, forces, solutions, and consequences are presented in terms of patterns and frame-works, so that solutions obtained for TAO can be appropriately applied to other real-time systems.
Pyarali, Irfan, "Patterns for Providing Real-Time Guarantees in DOC Middleware - Doctoral Dissertation, May 2002" Report Number: WUCSE-2002-28 (2002). All Computer Science and Engineering Research.