Dependable Computing

1Dependability Concepts and Taxonomy

1.1 Introduction

Every single failure in any computing device is a potential cause for concern. Reliable computing and fault tolerance, or, to use a more current term, dependable computing, is a longstanding area of research and practical implementation. This broad area of study started in the mid‐fifties with John von Neumann's construction of reliable systems from unreliable systems or components. Over the years, significant advancements and deployments have been made in commercial telecommunications, defense, and business applications that address a wide range of potential failures. Today, an explosion in the complexity of systems, applications, and operating systems has resulted in ever‐expanding failure sources. That, combined with explosive growth in computing as an enterprise in all areas of human endeavor, has brought forth new challenges and opportunities in designing dependable systems. Further, early detection, rapid concurrent/online diagnosis, and efficient and complete recovery are key to the design of systems that continue to operate in the event of errors. They must be complemented by ongoing analysis and monitoring of failures, supported by strong statistical models. In dependability, an understanding of real failures is critical in the design, implementation, deployment, and validation of reliability techniques. Design and validation must go hand in hand in developing new systems. While dependability techniques protect ...