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Continuous Availability
Continuous availability is an approach to computer system and application design that protects users against downtime, whatever the cause and ensures that users remain connected to their documents, data files and business applications. Continuous availability describes the information technology methods to ensure business continuity. In early days of computing, availability was not considered business critical. With the increasing use of mobile computing, global access to online business transactions and business-to-business communication, continuous availability is increasingly important based on the need to support customer access to information systems. Solutions to continuous availability exists in different forms and implementations depending on the software and hardware manufacturer. The goal of the discipline is to reduce the user or business application downtime, which can have a severe impact on business operations. Inevitably, such downtime can lead to loss of productivi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer System
A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These programs enable computers to perform a wide range of tasks. A computer system is a nominally complete computer that includes the hardware, operating system (main software), and peripheral equipment needed and used for full operation. This term may also refer to a group of computers that are linked and function together, such as a computer network or computer cluster. A broad range of industrial and consumer products use computers as control systems. Simple special-purpose devices like microwave ovens and remote controls are included, as are factory devices like industrial robots and computer-aided design, as well as general-purpose devices like personal computers and mobile devices like smartphones. Computers power the Internet, which links ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM Parallel Sysplex
In computing, a Parallel Sysplex is a cluster of IBM mainframes acting together as a single system image with z/OS. Used for disaster recovery, Parallel Sysplex combines data sharing and parallel computing to allow a cluster of up to 32 systems to share a workload for high performance and high availability. Sysplex In 1990, IBM mainframe computers introduced the concept of a Systems Complex, commonly called a Sysplex, with MVS/ESA SPV4.1. This allows authorized components in up to eight logical partitions (LPARs) to communicate and cooperate with each other using the XCF protocol. Components of a Sysplex include: * A common time source to synchronize all member systems' clocks. This can involve either a Sysplex timer (Model 9037), or the Server Time Protocol (STP) * Global Resource Serialization (GRS), which allows multiple systems to access the same resources concurrently, serializing where necessary to ensure exclusive access * Cross System Coupling Facility ( XCF), which ... [...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, 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 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 in the event of some partial f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-availability Cluster
High-availability clusters (also known as HA clusters, fail-over clusters) are groups of computers that support server applications that can be reliably utilized with a minimum amount of down-time. They operate by using high availability software to harness redundant computers in groups or clusters that provide continued service when system components fail. Without clustering, if a server running a particular application crashes, the application will be unavailable until the crashed server is fixed. HA clustering remedies this situation by detecting hardware/software faults, and immediately restarting the application on another system without requiring administrative intervention, a process known as failover. As part of this process, clustering software may configure the node before starting the application on it. For example, appropriate file systems may need to be imported and mounted, network hardware may have to be configured, and some supporting applications may need to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disaster Recovery
Disaster recovery is the process of maintaining or reestablishing vital infrastructure and systems following a natural or human-induced disaster, such as a storm or battle.It employs policies, tools, and procedures. Disaster recovery focuses on the information technology (IT) or technology systems supporting critical business functions as opposed to business continuity. This involves keeping all essential aspects of a business functioning despite significant disruptive events; it can therefore be considered a subset of business continuity. Disaster recovery assumes that the primary site is not immediately recoverable and restores data and services to a secondary site. IT service continuity IT Service Continuity (ITSC) is a subset of business continuity planning (BCP) that focuses on Recovery Point Objective (RPO) and Recovery Time Objective (RTO). It encompasses IT disaster recovery planning and wider IT resilience planning. It also incorporates IT infrastructure and services rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Continuity Planning
Business continuity may be defined as "the capability of an organization to continue the delivery of products or services at pre-defined acceptable levels following a disruptive incident", and business continuity planning (or business continuity and resiliency planning) is the process of creating systems of prevention and recovery to deal with potential threats to a company. In addition to prevention, the goal is to enable ongoing operations before and during execution of disaster recovery. Business continuity is the intended outcome of proper execution of both business continuity planning and disaster recovery. Several business continuity standards have been published by various standards bodies to assist in check listing ongoing planning tasks. An organization's resistance to failure is "the ability ... to withstand changes in its environment and still function". Often called resilience, it is a capability that enables organizations to either endure environmental changes witho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YugabyteDB
YugabyteDB is a high-performance transactional distributed SQL database for cloud-native applications, developed by Yugabyte. History Yugabyte was founded by ex-Facebook engineers Kannan Muthukkaruppan, Karthik Ranganathan, and Mikhail Bautin. At Facebook, they were part of the team that built and operated Cassandra and HBase during a period of significant growth in workloads such as Facebook Messenger and Facebook's Operational Data Store. The founders came together in February 2016 to build YugabyteDB, believing that the trends they experienced at Facebook – microservices, containerization, high availability, geographic distribution, APIs, and open-source – were relevant to all businesses, especially as they move from on-premise to cloud-native operations. YugabyteDB was initially available in two editions: community and enterprise. In July 2019, Yugabyte open sourced previously commercial features and launched YugabyteDB as open-source under the Apache 2.0 license. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tandem Computer
Tandem Computers, Inc. was the dominant manufacturer of fault-tolerant computer systems for ATM networks, banks, stock exchanges, telephone switching centers, and other similar commercial transaction processing applications requiring maximum uptime and zero 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. Tandem's NonStop systems use a number of independent identical processors and redundant storage devices and controllers to provide automatic high-speed "failover" in the case of a hardware or software failure. To contain the scope of failures and of corrupted data, these multi-computer systems have no shared central components, not even main memory. Conventional multi-com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratus VOS
Stratus VOS (Virtual Operating System) is a proprietary operating system running on Stratus Technologies fault-tolerant computer systems. VOS is available on Stratus's ftServer and Continuum platforms. VOS customers use it to support high-volume transaction processing applications which require continuous availability. VOS is notable for being one of the few operating systems which run on fully lockstepped hardware. During the 1980s, an IBM version of Stratus VOS existed and was called the System/88 Operating System. History VOS was designed from its inception as a high-security transaction-processing environment tailored to fault-tolerant hardware. It incorporates much of the design experience that came out of the MIT/Bell-Laboratories/General-Electric (later Honeywell) Multics project. In 1984, Stratus added a UNIX System V implementation called Unix System Facilities (USF) to VOS, integrating Unix and VOS at the kernel level. In recent years, Stratus has added POSIX-compli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dovecot (software)
Dovecot is an open-source IMAP and POP3 server for Unix-like operating systems, written primarily with security in mind. Timo Sirainen originated Dovecot and first released it in July 2002. Dovecot developers primarily aim to produce a lightweight, fast and easy-to-set-up open-source email server. The primary purpose of Dovecot is to act as mail storage server. Mail is delivered to the server using some mail delivery agent (MDA) and stored for later access with an email client (mail user agent, or MUA). Dovecot can also act as mail proxy server, forwarding connection to another mail server, or act as a lightweight MUA in order to retrieve and manipulate mail on remote server for e.g. mail migration. According to thOpen Email Survey as of 2020, Dovecot has an installed base of at least 2.9million IMAP servers, and has a global market share of 76.9% of all IMAP servers. The results of the same survey in 2019 gave figures of 2.6million and 76.2%, respectively. Features Dovecot ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Continuity
Business continuity may be defined as "the capability of an organization to continue the delivery of products or services at pre-defined acceptable levels following a disruptive incident", and business continuity planning (or business continuity and resiliency planning) is the process of creating systems of prevention and recovery to deal with potential threats to a company. In addition to prevention, the goal is to enable ongoing operations before and during execution of disaster recovery. Business continuity is the intended outcome of proper execution of both business continuity planning and disaster recovery. Several business continuity standards have been published by various standards bodies to assist in check listing ongoing planning tasks. An organization's resistance to failure is "the ability ... to withstand changes in its environment and still function". Often called resilience, it is a capability that enables organizations to either endure environmental changes witho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cockroach Labs
CockroachDB is a commercial distributed SQL database management system, developed by Cockroach Labs. History Cockroach Labs was founded in 2015 by ex-Google employees Spencer Kimball, Peter Mattis, and Ben Darnell. Cockroach Labs founders Kimball and Mattis were key members of the Google File System team while Darnell was a key member of the Google Reader team. While at Google, all three had previously used Google-owned DBMS’s Bigtable and its successor Spanner. After leaving Google, they wanted to design and build something similar on their own. Spencer Kimball wrote the first iteration of the design in January 2014, and began the open-source project on GitHub in February 2014, allowing outside access and contributions. Development on GitHub attracted substantial contributions, which made the project earn the ''Open Source Rookie of the Year'' award by Black Duck Software. The co-founders actively supported the project with conferences, networking, meet-ups, and fund-rais ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
