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In telecommunications, a recovery procedure is a process that attempts to bring a system back to a normal operating state. Examples:
In computing, a segmentation fault or access violation is a fault, or failure condition, raised by hardware with memory protection, notifying an operating system (OS) the software has attempted to access a restricted area of memory. On standard x86 computers, this is a form of general protection fault. The operating system kernel will, in response, usually perform some corrective action, generally passing the fault on to the offending process by sending the process a signal. Processes can in some cases install a custom signal handler, allowing them to recover on their own, but otherwise the OS default signal handler is used, generally causing abnormal termination of the process, and sometimes a core dump.
Tandem Computers, Inc. was the dominant manufacturer of fault-tolerant computer systems for ATM networks, banks, stock exchanges, telephone switching centers, 911 systems, and other similar commercial transaction processing applications requiring maximum uptime and no data loss. The company was founded by Jimmy Treybig in 1974 in Cupertino, California. It remained independent until 1997, when it became a server division within Compaq. It is now a server division within Hewlett Packard Enterprise, following Hewlett-Packard's acquisition of Compaq and the split of Hewlett-Packard into HP Inc. and Hewlett Packard Enterprise.
Intel's i960 was a RISC-based microprocessor design that became popular during the early 1990s as an embedded microcontroller. It became a best-selling CPU in that segment, along with the competing AMD 29000. In spite of its success, Intel stopped marketing the i960 in the late 1990s, as a result of a settlement with DEC whereby Intel received the rights to produce the StrongARM CPU. The processor continues to be used for a few military applications.
BiiN Corporation was a company created out of a joint research project by Intel and Siemens to develop fault tolerant high-performance multi-processor computers build on custom microprocessor designs. BiiN was an outgrowth of the Intel iAPX 432 multiprocessor project, ancestor of iPSC and nCUBE.
A general protection fault (GPF) in the x86 instruction set architectures (ISAs) is a fault initiated by ISA-defined protection mechanisms in response to an access violation caused by some running code, either in the kernel or a user program. The mechanism is first described in Intel manuals and datasheets for the Intel 80286 CPU, which was introduced in 1983; it is also described in section 9.8.13 in the Intel 80386 programmer's reference manual from 1986. A general protection fault is implemented as an interrupt. Some operating systems may also classify some exceptions not related to access violations, such as illegal opcode exceptions, as general protection faults, even though they have nothing to do with memory protection. If a CPU detects a protection violation, it stops executing the code and sends a GPF interrupt. In most cases, the operating system removes the failing process from the execution queue, signals the user, and continues executing other processes. If, however, the operating system fails to catch the general protection fault, i.e. another protection violation occurs before the operating system returns from the previous GPF interrupt, the CPU signals a double fault, stopping the operating system. If yet another failure occurs, the CPU is unable to recover; since 80286, the CPU enters a special halt state called "Shutdown", which can only be exited through a hardware reset. The IBM PC AT, the first PC-compatible system to contain an 80286, has hardware that detects the Shutdown state and automatically resets the CPU when it occurs. All descendants of the PC AT do the same, so in a PC, a triple fault causes an immediate system reset.
NonStop is a series of server computers introduced to market in 1976 by Tandem Computers Inc., beginning with the NonStop product line. It was followed by the Tandem Integrity NonStop line of lock-step fault-tolerant computers, now defunct. The original NonStop product line is currently offered by Hewlett Packard Enterprise since Hewlett-Packard Company's split in 2015. Because NonStop systems are based on an integrated hardware/software stack, Tandem and later HPE also developed the NonStop OS operating system for them.
A Byzantine fault is a condition of a system, particularly a distributed computing system, where a fault occurs such that different symptoms are presented to different observers, including imperfect information on whether a system component has failed. The term takes its name from an allegory, the "Byzantine generals problem", developed to describe a situation in which, to avoid catastrophic failure of a system, the system's actors must agree on a strategy, but some of these actors are unreliable in such a way as to cause other (good) actors to disagree on the strategy and they may be unaware of the disagreement.
Lockstep systems are fault-tolerant computer systems that run the same set of operations at the same time in parallel. The redundancy (duplication) allows error detection and error correction: the output from lockstep operations can be compared to determine if there has been a fault if there are at least two systems, and the error can be automatically corrected if there are at least three systems, via majority vote. The term "lockstep" originates from army usage, where it refers to synchronized walking, in which marchers walk as closely together as physically practical.
The Time-Triggered Protocol (TTP) is an open computer network protocol for control systems. It was designed as a time-triggered fieldbus for vehicles and industrial applications. and standardized in 2011 as SAE AS6003. TTP controllers have accumulated over 500 million flight hours in commercial DAL A aviation application, in power generation, environmental and flight controls. TTP is used in FADEC and modular aerospace controls, and flight computers. In addition, TTP devices have accumulated over 1 billion operational hours in SIL4 railway signalling applications.
Fault tolerance is the ability of a system to maintain proper operation despite failures or faults in one or more of its components. This capability is essential for high-availability, mission-critical, or even life-critical systems.
Power-system automation is the act of automatically controlling the power system via instrumentation and control devices. Substation automation refers to using data from Intelligent electronic devices (IED), control and automation capabilities within the substation, and control commands from remote users to control power-system devices.
Reliability, availability and serviceability (RAS), also known as reliability, availability, and maintainability (RAM), is a computer hardware engineering term involving reliability engineering, high availability, and serviceability design. The phrase was originally used by IBM as a term to describe the robustness of their mainframe computers.
Replication in computing involves sharing information so as to ensure consistency between redundant resources, such as software or hardware components, to improve reliability, fault-tolerance, or accessibility.
In systems design, a fail-fast system is one that 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 that any failures can be detected early. The responsibility of a fail-fast module is detecting errors, and then letting the next-highest level of the system handle them.
Fault Tolerant Messaging in the context of computer systems and networks, refers to a design approach and set of techniques aimed at ensuring reliable and continuous communication between components or nodes even in the presence of errors or failures. This concept is especially critical in distributed systems, where components may be geographically dispersed and interconnected through networks, making them susceptible to various potential points of failure.
Differential fault analysis (DFA) is a type of active side-channel attack in the field of cryptography, specifically cryptanalysis. The principle is to induce faults—unexpected environmental conditions—into cryptographic operations to reveal their internal states.
Apache Kafka is a distributed event store and stream-processing platform. It is an open-source system developed by the Apache Software Foundation written in Java and Scala. The project aims to provide a unified, high-throughput, low-latency platform for handling real-time data feeds. Kafka can connect to external systems via Kafka Connect, and provides the Kafka Streams libraries for stream processing applications. Kafka uses a binary TCP-based protocol that is optimized for efficiency and relies on a "message set" abstraction that naturally groups messages together to reduce the overhead of the network roundtrip. This "leads to larger network packets, larger sequential disk operations, contiguous memory blocks [...] which allows Kafka to turn a bursty stream of random message writes into linear writes."
Veritas Technologies LLC is an American international data management company headquartered in Santa Clara, California. The company has its origins in Tolerant Systems, founded in 1983 and later renamed Veritas Software. It specializes in storage management software including the first commercial journaling file system, VxFS, VxVM, VCS, the personal/small office backup software Backup Exec and the enterprise backup software, NetBackup. Veritas Record Now was an early CD recording software.
Parallel Computers, Inc. was an American computer manufacturing company, based in Santa Cruz, California, that made fault-tolerant computer systems based around the Unix operating system and various processors in the Motorola 68000 series.
Avalanche is a decentralized, open-source proof of stake blockchain with smart contract functionality. AVAX is the native cryptocurrency of the platform.
This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22.  | This article related to telecommunications is a stub. You can help Wikipedia by expanding it. |