Because of our present inability to produce error-free software, software fault tolerance is and will continue to be an important consideration in software systems. The root cause of software design errors is the complexity of the systems. Compounding the problems in building correct software is the difficulty in assessing the correctness of software for highly complex systems. After a brief overview of the software development processes, we note how hard-to-detect design faults are likely to be introduced during development and how software faults tend to be state-dependent and activated by particular input sequences. Although component reliability is an important quality measure for system level analysis, software reliability is hard to characterize and the use of post-verification reliability estimates remains a controversial issue. For some applications software safety is more important than reliability, and fault tolerance techniques used in those applications are aimed at preventing catastrophes. Single version software fault tolerance techniques discussed include system structuring and closure, atomic actions, inline fault detection, exception handling, and others. Multiversion techniques are based on the assumption that software built differently should fail differently and thus, if one of the redundant versions fails, it is expected that at least one of the other versions will provide an acceptable output. Recovery blocks, N-version programming, and other multiversion techniques are reviewed.Torres-Pomales, WilfredoLangley Research CenterSOFTWARE ENGINEERING; SOFTWARE RELIABILITY; COMPUTER PROGRAMMING; COMPUTER PROGRAMS; FAULT TOLERANCE; APPLICATIONS PROGRAMS (COMPUTERS); SOFTWARE DEVELOPMENT TOOLS; OPERATING SYSTEMS (COMPUTERS); COMPUTER SYSTEMS DESIGN; COMPLEX SYSTEMS; COMPONENT RELIABILITY; QUALITY CONTROL

Look to this innovative resource for the most comprehensive coverage of software fault tolerance techniques available in a single volume. It offers you a thorough understanding of the operation of critical software fault tolerance techniques and guides you through their design, operation and performance. You get an in-depth discussion on the advantages and disadvantages of specific techniques, so you can decide which ones are best suited for your work. The book examines key programming techniques such as assertions, checkpointing, and atomic actions, and provides design tips and models to assist in the development of critical fault tolerant software that helps ensure dependable performance. From software reliability, recovery, and redundancy... to design and data diverse software fault tolerance techniques, this practical reference provides detailed insight into techniques that can improve the overall dependability of your software.

This textbook serves as an introduction to fault-tolerance, intended for upper-division undergraduate students, graduate-level students and practicing engineers in need of an overview of the field. Readers will develop skills in modeling and evaluating fault-tolerant architectures in terms of reliability, availability and safety. They will gain a thorough understanding of fault tolerant computers, including both the theory of how to design and evaluate them and the practical knowledge of achieving fault-tolerance in electronic, communication and software systems. Coverage includes fault-tolerance techniques through hardware, software, information and time redundancy. The content is designed to be highly accessible, including numerous examples and exercises. Solutions and powerpoint slides are available for instructors.

Software patterns have revolutionized the way developer’s and architects think about how software is designed, built and documented. This new title in Wiley’s prestigious Series in Software Design Patterns presents proven techniques to achieve patterns for fault tolerant software. This is a key reference for experts seeking to select a technique appropriate for a given system. Readers are guided from concepts and terminology, through common principles and methods, to advanced techniques and practices in the development of software systems. References will provide access points to the key literature, including descriptions of exemplar applications of each technique. Organized into a collection of software techniques, specific techniques can be easily found with sufficient detail to allow appropriate choices for the system being designed.

Fault-Tolerant Systems is the first book on fault tolerance design with a systems approach to both hardware and software. No other text on the market takes this approach, nor offers the comprehensive and up-to-date treatment that Koren and Krishna provide. This book incorporates case studies that highlight six different computer systems with fault-tolerance techniques implemented in their design. A complete ancillary package is available to lecturers, including online solutions manual for instructors and PowerPoint slides. Students, designers, and architects of high performance processors will value this comprehensive overview of the field. - The first book on fault tolerance design with a systems approach - Comprehensive coverage of both hardware and software fault tolerance, as well as information and time redundancy - Incorporated case studies highlight six different computer systems with fault-tolerance techniques implemented in their design - Available to lecturers is a complete ancillary package including online solutions manual for instructors and PowerPoint slides

The growing complexity of modern software systems makes it increasingly difficult to ensure the overall dependability of software-intensive systems. Mastering system complexity requires design techniques that support clear thinking and rigorous validation and verification. Formal design methods together with fault-tolerant design techniques help to achieve this. Therefore, there is a clear need for methods that enable rigorous modeling and the development of complex fault-tolerant systems. This book is an outcome of the workshop on Methods, Models and Tools for Fault Tolerance, MeMoT 2007, held in conjunction with the 6th international conference on Integrated Formal Methods, iFM 2007, in Oxford, UK, in July 2007. The authors of the best workshop papers were asked to enhance and expand their work, and a number of well-established researchers working in the area contributed invited chapters in addition. From the 15 refereed and revised papers presented, 12 are versions reworked from the workshop and 3 papers are invited. The articles are organized in four topical sections on: formal reasoning about fault-tolerant systems and protocols; fault tolerance: modelling in B; fault tolerance in system development process; and fault-tolerant applications.

"This book increases awareness of the need for application-level fault-tolerance (ALFT) through introduction of problems and qualitative analysis of solutions"--Provided by publisher.