Measuring OS support for real-time CORBA ORBs

Abstract

The paper compares and evaluates the suitability of real time operating systems, VxWorks and LynxOS, and general purpose operating systems with real time extensions, Windows NT, Solaris, and Linux, for real time ORB middleware. While holding the hardware and ORB constant, we vary these operating systems and measure platform-specific variations in context switching overhead and priority inversions. Our findings illustrate that general purpose operating systems like Windows NT, Solaris, and Linux are not yet suited to meet the demands of applications with stringent QoS requirements. Although Linux provides good raw performance, its high jitter makes it unsuitable for real time applications. Both LynxOS and VxWorks do enable predictable and efficient ORB performance, however, thereby making them suitable as OS platforms for real time CORBA applications. In general, our results underscore the need for a measure-driven methodology to pinpoint sources of overhead and priority inversion in real time ORB endsystems.