|
Dynamo (storage System)
Dynamo is a set of techniques that together can form a highly available key-value structured storage system or a distributed data store. It has properties of both databases and distributed hash tables (DHTs). It was created to help address some scalability issues that Amazon.com's website experienced during the holiday season of 2004. By 2007, it was used in Amazon Web Services, such as its Simple Storage Service (S3). Relationship to DynamoDB Amazon DynamoDB is "built on the principles of Dynamo" and is a hosted service within the AWS infrastructure. However, while Dynamo is based on leaderless replication, DynamoDB uses single-leader replication. Principles * Incremental scalability: Dynamo should be able to scale out one storage host (or “node”) at a time, with minimal impact on both operators of the system and the system itself. * Symmetry: Every node in Dynamo should have the same set of responsibilities as its peers; there should be no distinguished node or nod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apache Cassandra
Cassandra is a free and open-source, distributed, wide-column store, NoSQL database management system designed to handle large amounts of data across many commodity servers, providing high availability with no single point of failure. Cassandra offers support for clusters spanning multiple datacenters, with asynchronous masterless replication allowing low latency operations for all clients. Cassandra was designed to implement a combination of Amazon's Dynamo distributed storage and replication techniques combined with Google's Bigtable data and storage engine model. History Avinash Lakshman, one of the authors of Amazon's Dynamo, and Prashant Malik initially developed Cassandra at Facebook to power the Facebook inbox search feature. Facebook released Cassandra as an open-source project on Google code in July 2008. In March 2009, it became an Apache Incubator project. On February 17, 2010, it graduated to a top-level project. Facebook developers named their database afte ... [...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 that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hinted Handoff
Hint and similar may refer to: * Hint (musician), musician Jonathan James from Sussex, England * Hint (SQL), a feature of the SQL computer language * Hint Water, a beverage company from San Francisco, California * Aadu Hint (1910–1989), Estonian writer * Font hinting, a process for optimizing the rasterization of vectors * Hints, Shropshire, a location in England * Hints, Staffordshire, a village in Staffordshire, England * Motorola Hint QA30, a mobile phone introduced by Motorola Acronyms * Hierarchical INTegration, a computer benchmark * Nord-Trøndelag University College Nord-Trøndelag University College (Norwegian: Høgskolen i Nord-Trøndelag) or HiNT was a Norwegian university college located throughout the county of Nord-Trøndelag. HiNT had about 5,500 students and 440 employees in 2013. In January 2016, th ... (Norwegian: Høgskolen i Nord-Trøndelag) * Health Information National Trends Survey {{disambiguation ... [...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] |
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 r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riak
Riak (pronounced "ree-ack" ) is a distributed NoSQL key-value data store based on Amazon's Dynamo paper, including its "tunable AP" approach, that is tunable consistency, to the tradeoffs imposed by the CAP Theorem. Riak offers high availability, fault tolerance, operational simplicity, and scalability. It moved to an entirely open-source project in August 2017, with many of the licensed Enterprise Edition features being incorporated after its acquisition by Bet365. Written in Erlang, Riak has fault tolerant data replication and automatic data distribution across the cluster for performance and resilience. Riak was originally developed by engineers employed by Basho Technologies and maintained by them until 2017 when the rights were sold to bet365 after Basho went into receivership. Riak was originally licensed using a freemium model. It is now completely open-source including all the enterprise features. Riak has a pluggable backend for its core storage, with the default storage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Project Voldemort
Voldemort is a distributed data store that was designed as a key-value store used by LinkedIn for highly-scalable storage. It is named after the fictional ''Harry Potter'' villain Lord Voldemort. Overview Voldemort does not try to satisfy arbitrary relations and the ACID properties, but rather is a big, distributed, persistent hash table. A 2012 study comparing systems for storing application performance management data reported that Voldemort, Apache Cassandra, and HBase all offered linear scalability in most cases, with Voldemort having the lowest latency and Cassandra having the highest throughput. In the parlance of Eric Brewer's CAP theorem, Voldemort is an AP type system. Voldemort's creator and primary corporate contributor, LinkedIn, has migrated all of their systems off of Voldemort as of approximately August 2018, with no replacement sponsor . Properties Voldemort uses in-memory caching to eliminate a separate caching tier. It has a storage layer that is possible to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NoSQL
A NoSQL (originally referring to "non- SQL" or "non-relational") database provides a mechanism for storage and retrieval of data that is modeled in means other than the tabular relations used in relational databases. Such databases have existed since the late 1960s, but the name "NoSQL" was only coined in the early 21st century, triggered by the needs of Web 2.0 companies. NoSQL databases are increasingly used in big data and real-time web applications. NoSQL systems are also sometimes called Not only SQL to emphasize that they may support SQL-like query languages or sit alongside SQL databases in polyglot-persistent architectures. Motivations for this approach include simplicity of design, simpler "horizontal" scaling to clusters of machines (which is a problem for relational databases), finer control over availability and limiting the object-relational impedance mismatch. The data structures used by NoSQL databases (e.g. key–value pair, wide column, graph, or document ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gossip Protocol
A gossip protocol or epidemic protocol is a procedure or process of computer peer-to-peer communication that is based on the way epidemics spread. Some distributed systems use peer-to-peer gossip to ensure that data is disseminated to all members of a group. Some ad-hoc networks have no central registry and the only way to spread common data is to rely on each member to pass it along to their neighbors. Communication The concept of ''gossip communication'' can be illustrated by the analogy of office workers spreading rumors. Let's say each hour the office workers congregate around the water cooler. Each employee pairs off with another, chosen at random, and shares the latest gossip. At the start of the day, Dave starts a new rumor: he comments to Bob that he believes that Charlie dyes his mustache. At the next meeting, Bob tells Alice, while Dave repeats the idea to Eve. After each water cooler rendezvous, the number of individuals who have heard the rumor roughly doubles (thoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merkle Trees
In cryptography and computer science, a hash tree or Merkle tree is a tree in which every "leaf" (node) is labelled with the cryptographic hash of a data block, and every node that is not a leaf (called a ''branch'', ''inner node'', or ''inode'') is labelled with the cryptographic hash of the labels of its child nodes. A hash tree allows efficient and secure verification of the contents of a large data structure. A hash tree is a generalization of a hash list and a hash chain. Demonstrating that a leaf node is a part of a given binary hash tree requires computing a number of hashes proportional to the logarithm of the number of leaf nodes in the tree. Conversely, in a hash list, the number is proportional to the number of leaf nodes itself. A Merkle tree is therefore an efficient example of a cryptographic commitment scheme, in which the root of the tree is seen as a commitment and leaf nodes may be revealed and proven to be part of the original commitment. The concept of a hash ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sloppy Quorums
{{disambiguation ...
Sloppy may refer to: * Sloppy Thurston (1899–1973), American baseball player * Sloppy Smurf, a Smurfs character * Sloppy, sister of Slimey the Worm, a pet of Oscar the Grouch in the children's television series ''Sesame Street'' * Sloppy, title character in the 2012 film ''Sloppy the Psychotic'' See also * * * Dirty (other) * Filth (other) * Messy (other) * Slop (other) Slop or SLOP may refer to: *Slop (clothing) *Hose (clothing) *Slop is the common name for household food scraps * Strategic Lateral Offset Procedure, in aviation, a procedure for avoiding collisions * a popular term for Backlash (engineering) *'' ... [...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] |
