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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 or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Program
A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components. A computer program in its human-readable form is called source code. Source code needs another computer program to execute because computers can only execute their native machine instructions. Therefore, source code may be translated to machine instructions using the language's compiler. ( Assembly language programs are translated using an assembler.) The resulting file is called an executable. Alternatively, source code may execute within the language's interpreter. If the executable is requested for execution, then the operating system loads it into memory and starts a process. The central processing unit will soon switch to this process so it can fetch, decode, and then execute each machine instruction. If the source code is requested for execution, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microreboot
Microrebooting is a technique used to recover from failures in crash-only software systems. Instead of rebooting the whole system, only subsets of fine-grain components are restarted. The granularity of components is typically finer than the process level (e.g., EJB-level in Java EE systems). The goal of confining the reboot to fine-grain components is threefold: to reduce the amount of time it takes for the system to return to service, to minimize the failure's disruption to the system and its users, and to preserve as much in-memory application data as possible. The concept was proposed in 2001 by George Candea and Armando Fox, while the former was a graduate student at Stanford University. It was initially reduced to practice in systems such as a satellite ground station control system and a Java EE application server; later on it formed the basis of the design of commercial systems like Aster Data Systems Aster Data Systems was a data management and analysis software co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Corruption
In the pursuit of knowledge, data (; ) is a collection of discrete values that convey information, describing quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted. A datum is an individual value in a collection of data. Data is usually organized into structures such as tables that provide additional context and meaning, and which may themselves be used as data in larger structures. Data may be used as variables in a computational process. Data may represent abstract ideas or concrete measurements. Data is commonly used in scientific research, economics, and in virtually every other form of human organizational activity. Examples of data sets include price indices (such as consumer price index), unemployment rates, literacy rates, and census data. In this context, data represents the raw facts and figures which can be used in such a manner in order to capture the useful information out of it. Da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Word Processor
A word processor (WP) is a device or computer program that provides for input, editing, formatting, and output of text, often with some additional features. Word processor (electronic device), Early word processors were stand-alone devices dedicated to the function, but current word processors are word processor programs running on general purpose computers. The functions of a word processor program fall somewhere between those of a simple text editor and a fully functioned desktop publishing program. However, the distinctions between these three have changed over time and were unclear after 2010. Background Word processors did not develop ''out'' of computer technology. Rather, they evolved from mechanical machines and only later did they merge with the computer field. The history of word processing is the story of the gradual automation of the physical aspects of writing and editing, and then to the refinement of the technology to make it available to corporations and Indi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persistent State
In computer science, persistent memory is any method or apparatus for efficiently storing data structures such that they can continue to be accessed using memory instructions or memory APIs even after the end of the process that created or last modified them. Often confused with non-volatile random-access memory (NVRAM), persistent memory is instead more closely linked to the concept of persistence in its emphasis on program state that exists outside the fault zone of the process that created it. (A process is a program under execution. The fault zone of a process is that subset of program state which could be corrupted by the process continuing to execute after incurring a fault, for instance due to an unreliable component used in the computer executing the program.) Efficient, memory-like access is the defining characteristic of persistent memory. It can be provided using microprocessor memory instructions, such as load and store. It can also be provided using APIs that impleme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erlang (programming Language)
Erlang ( ) is a general-purpose, concurrent, functional programming language, and a garbage-collected runtime system. The term Erlang is used interchangeably with Erlang/OTP, or Open Telecom Platform (OTP), which consists of the Erlang runtime system, several ready-to-use components (OTP) mainly written in Erlang, and a set of design principles for Erlang programs. The Erlang runtime system is designed for systems with these traits: *Distributed *Fault-tolerant * Soft real-time * Highly available, non-stop applications *Hot swapping, where code can be changed without stopping a system. The Erlang programming language has immutable data, pattern matching, and functional programming. The sequential subset of the Erlang language supports eager evaluation, single assignment, and dynamic typing. A normal Erlang application is built out of hundreds of small Erlang processes. It was originally proprietary software within Ericsson, developed by Joe Armstrong, Robert Virding, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ericsson
(lit. "Telephone Stock Company of LM Ericsson"), commonly known as Ericsson, is a Swedish multinational networking and telecommunications company headquartered in Stockholm. The company sells infrastructure, software, and services in information and communications technology for telecommunications service providers and enterprises, including, among others, 3G, 4G, and 5G equipment, and Internet Protocol (IP) and optical transport systems. The company employs around 100,000 people and operates in more than 180 countries. Ericsson has over 57,000 granted patents. Ericsson has been a major contributor to the development of the telecommunications industry and is one of the leaders in 5G. The company was founded in 1876 by Lars Magnus Ericsson and is jointly controlled by the Wallenberg family through its holding company Investor AB, and the universal bank Handelsbanken through its investment company Industrivärden. The Wallenbergs and the Handelsbanken sphere acquired their v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Swapping
Hot swapping is the replacement or addition of components to a computer system without stopping, shutting down, or rebooting the system; hot plugging describes the addition of components only. Components which have such functionality are said to be ''hot-swappable'' or ''hot-pluggable''; likewise, components which do not are ''cold-swappable'' or ''cold-pluggable''. Most desktop computer hardware, such as CPUs and memory, are only cold-pluggable. However, it is common for mid to high-end servers and mainframes to feature hot-swappable capability for hardware components, such as CPU, memory, PCIe, SATA and SAS drives. An example of hot swapping is the express ability to pull a Universal Serial Bus (USB) peripheral device, such as a thumb drive, external hard disk drive (HDD), mouse, keyboard, or printer out of a computer's USB slot or peripheral hub without ejecting it first. Most smartphones and tablets with tray-loading holders can interchange SIM cards without poweri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Telecom Platform
OTP is a collection of useful middleware, libraries, and tools written in the Erlang programming language. It is an integral part of the open-source distribution of Erlang. The name OTP was originally an acronym for Open Telecom Platform, which was a branding attempt before Ericsson released Erlang/OTP as open source. However neither Erlang nor OTP is specific to telecom applications. The OTP distribution is supported and maintained by the OTP product unit at Ericsson, who released Erlang/OTP as open-source in the late 90s, to ensure its independence from a single vendor and to increase awareness of the language. It contains: *an Erlang interpreter (which is called '' BEAM''); *an Erlang compiler; *a protocol for communication between servers (nodes); *a CORBA Object Request Broker; *a static analysis tool called Dialyzer; *a distributed database server (Mnesia); and *many other libraries. History Early days Originally named Open System, it was started by Ericsson in late 1995 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosave
Autosave is a saving function in many computer applications and video games which automatically saves the current changes or progress in the program or game, intending to prevent data loss should the user be otherwise prevented from doing so manually by a crash, freeze or user error. Autosaving is typically done either in predetermined intervals or before, during, and after a complex editing task is begun. Application software It has traditionally been seen as a feature to protect documents in an application or system failure (crash), and autosave backups are often purged whenever the user finishes their work. An alternative paradigm is to have all changes saved continuously (as with pen and paper) and all versions of a document available for review. This would remove the need for saving documents entirely. There are challenges to implementation at the file, application and operating system levels. For example, in Microsoft Office, this option is called ''AutoRecover'' and, by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microreboot
Microrebooting is a technique used to recover from failures in crash-only software systems. Instead of rebooting the whole system, only subsets of fine-grain components are restarted. The granularity of components is typically finer than the process level (e.g., EJB-level in Java EE systems). The goal of confining the reboot to fine-grain components is threefold: to reduce the amount of time it takes for the system to return to service, to minimize the failure's disruption to the system and its users, and to preserve as much in-memory application data as possible. The concept was proposed in 2001 by George Candea and Armando Fox, while the former was a graduate student at Stanford University. It was initially reduced to practice in systems such as a satellite ground station control system and a Java EE application server; later on it formed the basis of the design of commercial systems like Aster Data Systems Aster Data Systems was a data management and analysis software co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
End-to-end Principle
The end-to-end principle is a design framework in computer networking. In networks designed according to this principle, guaranteeing certain application-specific features, such as reliability and security, requires that they reside in the communicating end nodes of the network. Intermediary nodes, such as gateways and routers, that exist to establish the network, may implement these to improve efficiency but cannot guarantee end-to-end correctness. The essence of what would later be called the end-to-end principle was contained in the work of Paul Baran and Donald Davies on packet-switched networks in the 1960s. Louis Pouzin pioneered the use of the end-to-end strategy in the CYCLADES network in the 1970s. The principle was first articulated explicitly in 1981 by Saltzer, Reed, and Clark. The meaning of the end-to-end principle has been continuously reinterpreted ever since its initial articulation. Also, noteworthy formulations of the end-to-end principle can be found befor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
