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Distributed Data Store
A distributed data store is a computer network where information is stored on more than one node, often in a replicated fashion. It is usually specifically used to refer to either a distributed database where users store information on a ''number of nodes'', or a computer network in which users store information on a ''number of peer network nodes''. Distributed databases Distributed databases are usually non-relational databases that enable a quick access to data over a large number of nodes. Some distributed databases expose rich query abilities while others are limited to a key-value store semantics. Examples of limited distributed databases are Google's Bigtable, which is much more than a distributed file system or a peer-to-peer network, Amazon's Dynamo and Microsoft Azure Storage. As the ability of arbitrary querying is not as important as the availability, designers of distributed data stores have increased the latter at an expense of consistency. But the high-speed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Network
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies, based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies. The nodes of a computer network can include personal computers, servers, networking hardware, or other specialised or general-purpose hosts. They are identified by network addresses, and may have hostnames. Hostnames serve as memorable labels for the nodes, rarely changed after initial assignment. Network addresses serve for locating and identifying the nodes by communication protocols such as the Internet Protocol. Computer networks may be classified by many criteria, including the transmission medium used to carry signals, bandwidth, communications pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peer-to-peer
Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer network of nodes. Peers make a portion of their resources, such as processing power, disk storage or network bandwidth, directly available to other network participants, without the need for central coordination by servers or stable hosts. Peers are both suppliers and consumers of resources, in contrast to the traditional client–server model in which the consumption and supply of resources are divided. While P2P systems had previously been used in many application domains, the architecture was popularized by the file sharing system Napster, originally released in 1999. The concept has inspired new structures and philosophies in many areas of human interaction. In such social contexts, peer-to-peer as a meme refers to the egalitarian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Affero General Public License
The GNU Affero General Public License (GNU AGPL) is a free, copyleft license published by the Free Software Foundation in November 2007, and based on the GNU General Public License, version 3 and the Affero General Public License. The Free Software Foundation has recommended that the GNU AGPLv3 be considered for any software that will commonly be run over a network.List of free-software licences on the FSF website "''We recommend that developers consider using the GNU AGPL for any software which will commonly be run over a network.''" The Free Software Foundation explains the need for the license in the case when a free program is run on a server: The GNU Affero General Public License is a modified version of the ordinary GNU GPL version 3. It has one added requirement: if yo ... |
Aerospike (database)
Aerospike Database is a flash memory and in-memory open source distributed key value NoSQL database management system, marketed by the company also named Aerospike. History Aerospike was first known as Citrusleaf. In August 2012, the company - which had been providing its database since 2010 - rebranded both the company and software name to Aerospike. The name "Aerospike" is derived from the aerospike engine, a type of rocket nozzle that is able to maintain its output efficiency over a large range of altitudes, and is intended to refer to the software's ability to scale up. In 2012, Aerospike acquired AlchemyDB, and integrated the two databases' functions, including the addition of a relational data management system. On June 24, 2014, Aerospike was opensourced under the AGPL 3.0 license for the Aerospike database server and the Apache License Version 2.0 for its Aerospike client software development kit. Release history Features Aerospike Database is modeled under the sha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apache License 2
The Apache () are a group of culturally related Native American tribes in the Southwestern United States, which include the Chiricahua, Jicarilla, Lipan, Mescalero, Mimbreño, Ndendahe (Bedonkohe or Mogollon and Nednhi or Carrizaleño and Janero), Salinero, Plains (Kataka or Semat or "Kiowa-Apache") and Western Apache ( Aravaipa, Pinaleño, Coyotero, Tonto). Distant cousins of the Apache are the Navajo, with whom they share the Southern Athabaskan languages. There are Apache communities in Oklahoma and Texas, and reservations in Arizona and New Mexico. Apache people have moved throughout the United States and elsewhere, including urban centers. The Apache Nations are politically autonomous, speak several different languages, and have distinct cultures. Historically, the Apache homelands have consisted of high mountains, sheltered and watered valleys, deep canyons, deserts, and the southern Great Plains, including areas in what is now Eastern Arizona, Northern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apache Accumulo
Apache Accumulo is a highly scalable sorted, distributed key-value store based on Google's Bigtable. It is a system built on top of Apache Hadoop, Apache ZooKeeper, and Apache Thrift. Written in Java, Accumulo has cell-level access labels and server-side programming mechanisms. According to DB-Engines ranking, Accumulo is the third most popular NoSQL wide column store behind Apache Cassandra and HBase and the 67th most popular database engine of any type (complete) as of 2018. History Accumulo was created in 2008 by the US National Security Agency and contributed to the Apache Foundation as an incubator project in September 2011.NSA Submits Open Source, Secure Database To Apache - Government Informationweek.com (2011-09-06). Retrieved on 2013-09-18. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Availability
High availability (HA) is a characteristic of a system which aims to ensure an agreed level of operational performance, usually uptime, for a higher than normal period. Modernization has resulted in an increased reliance on these systems. For example, hospitals and data centers require high availability of their systems to perform routine daily activities. Availability refers to the ability of the user community to obtain a service or good, access the system, whether to submit new work, update or alter existing work, or collect the results of previous work. If a user cannot access the system, it is – from the user's point of view – ''unavailable''. Generally, the term ''downtime'' is used to refer to periods when a system is unavailable. Principles There are three principles of systems design in reliability engineering which can help achieve high availability. # Elimination of single points of failure. This means adding or building redundancy into the system so th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forward Error Correction
In computing, telecommunication, information theory, and coding theory, an error correction code, sometimes error correcting code, (ECC) is used for controlling errors in data over unreliable or noisy communication channels. The central idea is the sender encodes the message with redundant information in the form of an ECC. The redundancy allows the receiver to detect a limited number of errors that may occur anywhere in the message, and often to correct these errors without retransmission. The American mathematician Richard Hamming pioneered this field in the 1940s and invented the first error-correcting code in 1950: the Hamming (7,4) code. ECC contrasts with error detection in that errors that are encountered can be corrected, not simply detected. The advantage is that a system using ECC does not require a reverse channel to request retransmission of data when an error occurs. The downside is that there is a fixed overhead that is added to the message, thereby requiring a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parchive
Parchive (a portmanteau of parity archive, and formally known as Parity Volume Set Specification) is an erasure code system that produces par files for checksum verification of data integrity, with the capability to perform data recovery operations that can repair or regenerate corrupted or missing data. Parchive was originally written to solve the problem of reliable file sharing on Usenet, but it can be used for protecting any kind of data from data corruption, disc rot, bit rot, and accidental or malicious damage. Despite the name, Parchive uses more advanced techniques (specifically error correction codes) than simplistic parity methods of error detection. As of 2014, PAR1 is obsolete, PAR2 is mature for widespread use, and PAR3 is a discontinued experimental version developed by MultiPar author Yutaka Sawada. The original SourceForge Parchive project has been inactive since April 30, 2015. A new PAR3 specification has been worked on since April 28, 2019 by PAR2 specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Error Detection And Correction
In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communication channels. Many communication channels are subject to channel noise, and thus errors may be introduced during transmission from the source to a receiver. Error detection techniques allow detecting such errors, while error correction enables reconstruction of the original data in many cases. Definitions ''Error detection'' is the detection of errors caused by noise or other impairments during transmission from the transmitter to the receiver. ''Error correction'' is the detection of errors and reconstruction of the original, error-free data. History In classical antiquity, copyists of the Hebrew Bible were paid for their work according to the number of stichs (lines of verse). As the prose books of the Bible were hardly ever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfect Dark (P2P)
is a peer-to-peer file-sharing (P2P) application from Japan designed for use with Microsoft Windows. It was launched in 2006. Its author is known by the pseudonym . Perfect Dark was developed with the intention for it to be the successor to both Winny and Share software. While Japan's Association for Copyright of Computer Software reported that in January 2014, the number of nodes connected on Perfect Dark () was less than on Share (), but more than on Winny (), Netagent in 2018 reported Winny being the largest with 50 000 nodes followed by Perfect Dark with 30 000 nodes followed by Share with 10 000. Netagent asserts that the number of nodes on Perfect Dark have fallen since 2015 while the numbers of Winny hold steady. Netagent reports that users of Perfect Dark are most likely to share books/manga. As of version 1.02 (2008), code-named "Stand Alone Complex", there is support for the program to run in English, an option that can be selected when the program is installed. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Share (P2P)
is the name for a closed-source P2P application being developed in Japan by ファイル倉庫, a pseudonym translating as 'file warehouse.' ''Share'' was developed to be the successor to Winny. Like Winny, ''Share'' functions using a distributed data store referred to as a cache with each computer acting as a node in the network. Netagent published a survey in June 2018 suggesting that Share was the third most popular p2p network in Japan after Winny and Perfect Dark (P2P) with approximately 10,000 nodes connecting each day over Golden Week, down from 30,000 in 2015. Background Share's logo refers to the Laughing Man, which is a fictional character from the anime series Ghost in the Shell: Stand Alone Complex, as an anonymous hacker. ''Share'' uses encryption to hide the identity of who is transferring or what they are transferring. It is non-centralized so it cannot be easily shut down and it supports multiple source "swarm" downloading. All files are transferred encrypt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
