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Gizzard (Scala Framework)
Gizzard is an Open-source software, open source sharding Software framework, framework to create custom fault-tolerant, distributed databases. It was initially used by Twitter and emerged from a wide variety of data storage problems. Gizzard operates as a middleware networking service that runs on the Java Virtual Machine. It manages Partition (database), partitioning data across arbitrary backend datastores, that allows it to be accessed efficiently. The partitioning rules are stored in a forwarding table that maps key ranges to partitions. Each partition manages its own Replication (computer science), replication through a declarative replication tree. Gizzard handles both physical and logical shards. Physical shards point to a physical database backend whereas logical shards are trees of other shards. In addition Gizzard also supports Data migration, migrations and gracefully handles failures. The system is made eventually consistent by requiring that all write operations are idem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twitter
Twitter is an online social media and social networking service owned and operated by American company Twitter, Inc., on which users post and interact with 280-character-long messages known as "tweets". Registered users can post, like, and 'Reblogging, retweet' tweets, while unregistered users only have the ability to read public tweets. Users interact with Twitter through browser or mobile Frontend and backend, frontend software, or programmatically via its APIs. Twitter was created by Jack Dorsey, Noah Glass, Biz Stone, and Evan Williams (Internet entrepreneur), Evan Williams in March 2006 and launched in July of that year. Twitter, Inc. is based in San Francisco, California and has more than 25 offices around the world. , more than 100 million users posted 340 million tweets a day, and the service handled an average of 1.6 billion Web search query, search queries per day. In 2013, it was one of the ten List of most popular websites, most-visited websites and has been de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. The majority of tree species are angiosperms or hardwoods; of the rest, many are gymnosperms or softwoods. Trees tend to be long-lived, some reaching several thousand years old. Trees have been in existence for 370 million years. It is estimated that there are some three trillion mature trees in the world. A tree typically has many secondary branches supported clear of the ground by the trunk. This trunk typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Partitioning
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. Dat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Database Management Systems
Free may refer to: Concept * Freedom, having the ability to do something, without having to obey anyone/anything * Freethought, a position that beliefs should be formed only on the basis of logic, reason, and empiricism * Emancipate, to procure political rights, as for a disenfranchised group * Free will, control exercised by rational agents over their actions and decisions * Free of charge, also known as gratis. See Gratis vs libre. Computing * Free (programming), a function that releases dynamically allocated memory for reuse * Free format, a file format which can be used without restrictions * Free software, software usable and distributable with few restrictions and no payment * Freeware, a broader class of software available at no cost Mathematics * Free object ** Free abelian group ** Free algebra ** Free group ** Free module ** Free semigroup * Free variable People * Free (surname) * Free (rapper) (born 1968), or Free Marie, American rapper and media pers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structured Storage
Structuring, also known as smurfing in banking jargon, is the practice of executing financial transactions such as making bank deposits in a specific pattern, calculated to avoid triggering financial institutions to file reports required by law, such as the United States' Bank Secrecy Act (BSA) and Internal Revenue Code section 6050I (relating to the requirement to file Form 8300). Structuring may be done in the context of money laundering, fraud, and other financial crimes. Legal restrictions on structuring are concerned with limiting the size of domestic transactions for individuals. Definition Structuring is the act of parceling what would otherwise be a large financial transaction into a series of smaller transactions to avoid scrutiny by regulators and law enforcement. Typically each of the smaller transactions is executed in an amount below some statutory limit that normally does not require a financial institution to file a report with a government agency. Criminal en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Synchronization
Data synchronization is the process of establishing consistency between source and target data stores, and the continuous harmonization of the data over time. It is fundamental to a wide variety of applications, including file synchronization and mobile device synchronization. Data synchronization can also be useful in encryption for synchronizing public key servers. File-based solutions There are tools available for file synchronization, version control ( CVS, Subversion, etc.), distributed filesystems (Coda, etc.), and mirroring (rsync, etc.), in that all these attempt to keep sets of files synchronized. However, only version control and file synchronization tools can deal with modifications to more than one copy of the files. * File synchronization is commonly used for home backups on external hard drives or updating for transport on USB flash drives. The automatic process prevents copying already identical files, thus can save considerable time relative to a manual copy, al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FlockDB
FlockDB is an open-source distributed, fault-tolerant graph database for managing wide but shallow network graphs. It was initially used by Twitter to store relationships between users, e.g. followings and favorites. FlockDB differs from other graph databases, e.g. Neo4j in that it is not designed for multi-hop graph traversal but rather for rapid set operations, not unlike the primary use-case for Redis sets. Since it is still in the process of being packaged for outside of Twitter use, the code is still very rough and hence there is no stable release available yet. FlockDB was posted on GitHub shortly after Twitter released its Gizzard framework, which it uses to query the FlockDB distributed datastore. The database is licensed under the Apache License. Twitter no longer supports FlockDB. See also * Gizzard (Scala framework) Gizzard is an Open-source software, open source sharding Software framework, framework to create custom fault-tolerant, distributed databases. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Database
A distributed database is a database in which data is stored across different physical locations. It may be stored in multiple computers located in the same physical location (e.g. a data centre); or maybe dispersed over a network of interconnected computers. Unlike parallel systems, in which the processors are tightly coupled and constitute a single database system, a distributed database system consists of loosely coupled sites that share no physical components. System administrators can distribute collections of data (e.g. in a database) across multiple physical locations. A distributed database can reside on organised network servers or decentralised independent computers on the Internet, on corporate intranets or extranets, or on other organisation networks. Because distributed databases store data across multiple computers, distributed databases may improve performance at end-user worksites by allowing transactions to be processed on many machines, instead of being limite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Hash Table
A distributed hash table (DHT) is a distributed system that provides a lookup service similar to a hash table: key–value pairs are stored in a DHT, and any participating node can efficiently retrieve the value associated with a given key. The main advantage of a DHT is that nodes can be added or removed with minimum work around re-distributing keys. ''Keys'' are unique identifiers which map to particular ''values'', which in turn can be anything from addresses, to documents, to arbitrary data. Responsibility for maintaining the mapping from keys to values is distributed among the nodes, in such a way that a change in the set of participants causes a minimal amount of disruption. This allows a DHT to scale to extremely large numbers of nodes and to handle continual node arrivals, departures, and failures. DHTs form an infrastructure that can be used to build more complex services, such as anycast, cooperative web caching, distributed file systems, domain name services, instant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GitHub
GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, continuous integration, and wikis for every project. Headquartered in California, it has been a subsidiary of Microsoft since 2018. It is commonly used to host open source software development projects. As of June 2022, GitHub reported having over 83 million developers and more than 200 million repositories, including at least 28 million public repositories. It is the largest source code host . History GitHub.com Development of the GitHub.com platform began on October 19, 2007. The site was launched in April 2008 by Tom Preston-Werner, Chris Wanstrath, P. J. Hyett and Scott Chacon after it had been made available for a few months prior as a beta release. GitHub has an annual keynote called GitHub Universe. Organizational ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commutativity
In mathematics, a binary operation is commutative if changing the order of the operands does not change the result. It is a fundamental property of many binary operations, and many mathematical proofs depend on it. Most familiar as the name of the property that says something like or , the property can also be used in more advanced settings. The name is needed because there are operations, such as division and subtraction, that do not have it (for example, ); such operations are ''not'' commutative, and so are referred to as ''noncommutative operations''. The idea that simple operations, such as the multiplication and addition of numbers, are commutative was for many years implicitly assumed. Thus, this property was not named until the 19th century, when mathematics started to become formalized. A similar property exists for binary relations; a binary relation is said to be symmetric if the relation applies regardless of the order of its operands; for example, equality is s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Idempotent
Idempotence (, ) is the property of certain operation (mathematics), operations in mathematics and computer science whereby they can be applied multiple times without changing the result beyond the initial application. The concept of idempotence arises in a number of places in abstract algebra (in particular, in the theory of projector (linear algebra), projectors and closure operators) and functional programming (in which it is connected to the property of referential transparency). The term was introduced by American mathematician Benjamin Peirce in 1870 in the context of elements of algebras that remain invariant when raised to a positive integer power, and literally means "(the quality of having) the same power", from + ''wikt:potence, potence'' (same + power). Definition An element x of a set S equipped with a binary operator \cdot is said to be ''idempotent'' under \cdot if : . The ''binary operation'' \cdot is said to be ''idempotent'' if : . Examples * In the monoid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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