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Fail-fast
In systems design, a fail-fast system is one which immediately reports at its interface any condition that is likely to indicate a failure. Fail-fast systems are usually designed to stop normal operation rather than attempt to continue a possibly flawed process. Such designs often check the system's state at several points in an operation, so any failures can be detected early. The responsibility of a fail-fast module is detecting errors, then letting the next-highest level of the system handle them. Hardware and software Fail-fast systems or modules are desirable in several circumstances: * Fail-fast architectures are based on an error handling policy where any detected error or non-contemplated state makes the system fail (fast). In some sense the error handling policy is the opposite of that used in a fault-tolerant system. In a fault-tolerant system a error handling policy is established to have redundant components and move computation requests to alive components when some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault-tolerant System
Fault tolerance is the property that enables a system to continue operating properly in the event of the failure of one or more faults within some of its components. If its operating quality decreases at all, the decrease is proportional to the severity of the failure, as compared to a naively designed system, in which even a small failure can cause total breakdown. Fault tolerance is particularly sought after in high-availability, Mission critical, mission-critical, or even life-critical systems. The ability of maintaining functionality when portions of a system break down is referred to as graceful degradation. A fault-tolerant design enables a system to continue its intended operation, possibly at a reduced level, rather than failing completely, when some part of the system failure, fails. The term is most commonly used to describe computer systems designed to continue more or less fully operational with, perhaps, a reduction in throughput or an increase in response time (tech ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fail-stop
{{Unreferenced, date=June 2019, bot=noref (GreenC bot) A fail-stop subset of a computer language is one that has the same semantics as the original, except in the case where an exceptional condition arises. The fail-stop subset must report an exceptional condition whenever the superset language reports one, but may additionally report an exceptional condition in other cases. Fail-stop languages are often used in computer systems where correctness is very important, since it is easier to make such systems fail-fast. For example, the "+" operator in many programming languages is not associative because of the possibility of floating-point overflow. Repairing these languages to fail fast when commonly assumed properties do not hold makes it much easier to write and verify correct code. Examples In many widely used programming languages the code below might reduce the bank account value if the deposited amount or old account value is very large, by causing an overflowed value to b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systems Design
Systems design interfaces, and data for an electronic control system to satisfy specified requirements. System design could be seen as the application of system theory to product development. There is some overlap with the disciplines of system analysis, system architecture and system engineering. Overview If the broader topic of product development "blends the perspective of marketing, design, and manufacturing into a single approach to product development," then design is the act of taking the marketing information and creating the design of the product to be manufactured. Systems design is therefore the process of defining and developing systems to satisfy specified requirements of the user. The basic study of system design is the understanding of component parts and their subsequent interaction with one another. Physical design The physical design relates to the actual input and output processes of the system. This is explained in terms of how data is input into a syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martin Fowler (software Engineer)
Martin Fowler (18 December 1963) is a British software developer, author and international public speaker on software development, specialising in object-oriented analysis and design, UML, patterns, and agile software development methodologies, including extreme programming. His 1999 book ''Refactoring'' popularised the practice of code refactoring. In 2004 he introduced a new architectural pattern, called Presentation Model (PM). Biography Fowler was born and grew up in Walsall, England, where he went to Queen Mary's Grammar School for his secondary education. He graduated at University College London in 1986. In 1994 he moved to the United States, where he lives near Boston, Massachusetts in the suburb of Melrose.Martin Fowler at martinfowler.com. Retrieved 2012-11-15. Fowler started working with software in the early 1980s. Out of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fail-silent System
A fail-silent system is a type of system that either provides the correct service, or provides no service at all (becomes silent). See also * Design by contract * Fail-fast *Fail-safe * Fail-stop *Fault tolerance Fault tolerance is the property that enables a system to continue operating properly in the event of the failure of one or more faults within some of its components. If its operating quality decreases at all, the decrease is proportional to the ... References Fault-tolerant computer systems Safety {{technology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fail-safe
In engineering, a fail-safe is a design feature or practice that in the event of a specific type of failure, inherently responds in a way that will cause minimal or no harm to other equipment, to the environment or to people. Unlike inherent safety to a particular hazard, a system being "fail-safe" does not mean that failure is impossible or improbable, but rather that the system's design prevents or mitigates unsafe consequences of the system's failure. That is, if and when a "fail-safe" system fails, it remains at least as safe as it was before the failure. Since many types of failure are possible, failure mode and effects analysis is used to examine failure situations and recommend safety design and procedures. Some systems can never be made fail-safe, as continuous availability is needed. Redundancy, fault tolerance, or contingency plans are used for these situations (e.g. multiple independently controlled and fuel-fed engines). Examples Mechanical or physical Examples ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Failing Badly
Failing badly and failing well are concepts in systems security and network security (and engineering in general) describing how a system reacts to failure. The terms have been popularized by Bruce Schneier, a cryptographer and security consultant.Homeland Insecurity , '' Atlantic Monthly'', September 2002 Failing badly A system that fails badly is one that has a catastrophic result when failure occurs. A can thus bring down the wh ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crash-only Software
Crash-only software refers to computer programs that handle failures by simply restarting, without attempting any sophisticated recovery. Correctly written components of crash-only software can microreboot to a known-good state without the help of a user. Since failure-handling and normal startup use the same methods, this can increase the chance that bugs in failure-handling code will be noticed, except when there are leftover artefacts, such as data corruption from a severe failure, that don't occur during normal startup. Crash-only software also has benefits for end-users. All too often, applications do not save their data and settings while running, only at the end of their use. For example, word processors usually save settings when they are closed. A crash-only application is designed to save all changed user settings soon after they are changed, so that the persistent state matches that of the running machine. No matter how an application terminates (be it a clean close ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accelerationism
Accelerationism is a range of Marxist and reactionary ideas in critical and social theory that call for the drastic intensification of capitalist growth, technological change and other social processes in order to destabilize existing systems and create radical social transformation, otherwise known as "acceleration". The term also refers to the post-Marxist idea that because of capitalism's internal contradictions and instabilities which can jeopardize its growth, the abolition of the system and its class structures could be brought about by its acceleration. Various ideas, including Gilles Deleuze and Félix Guattari's idea of deterritorialization, Jean Baudrillard's proposals for "fatal strategies", and aspects of the theoretical systems and processes developed by English philosopher, and later Dark Enlightenment commentator, Nick Land, are crucial influences on accelerationism, which aims to analyze and subsequently promote the social, economic, cultural, and libidina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Startup Company
A startup or start-up is a company or project undertaken by an entrepreneur to seek, develop, and validate a scalable business model. While entrepreneurship refers to all new businesses, including self-employment and businesses that never intend to become registered, startups refer to new businesses that intend to grow large beyond the solo founder. At the beginning, startups face high uncertainty and have high rates of failure, but a minority of them do go on to be successful and influential.Erin Griffith (2014)Why startups fail, according to their founders Fortune.com, 25 September 2014; accessed 27 October 2017 Actions Startups typically begin by a founder (solo-founder) or co-founders who have a way to solve a problem. The founder of a startup will begin market validation by problem interview, solution interview, and building a minimum viable product (MVP), i.e. a prototype, to develop and validate their business models. The startup process can take a long period of time (by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iteration
Iteration is the repetition of a process in order to generate a (possibly unbounded) sequence of outcomes. Each repetition of the process is a single iteration, and the outcome of each iteration is then the starting point of the next iteration. In mathematics and computer science, iteration (along with the related technique of recursion) is a standard element of algorithms. Mathematics In mathematics, iteration may refer to the process of iterating a function, i.e. applying a function repeatedly, using the output from one iteration as the input to the next. Iteration of apparently simple functions can produce complex behaviors and difficult problems – for examples, see the Collatz conjecture and juggler sequences. Another use of iteration in mathematics is in iterative methods which are used to produce approximate numerical solutions to certain mathematical problems. Newton's method is an example of an iterative method. Manual calculation of a number's square root is a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
