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Grid File System
A grid file system is a computer file system whose goal is improved reliability and availability by taking advantage of many smaller file storage areas. Components File systems contain up to three components: * File table (FAT table, MFT, etc.) * File data * Metadata (user permissions, etc.) A grid file system would have similar needs: * File table (or search index) * File data * Metadata Comparisons Because file systems are designed to appear as a single disk for a single computer to manage (entirely), many new challenges arise in a grid scenario whereby any single disk within the grid should be capable of handling requests for any data contained in the grid. Features Most file storage utilizes layers of redundancy to achieve a high level of data protection (inability to lose data). Current means of redundancy include replication and parity checks. Such redundancy can be implemented via a RAID array (whereby multiple physical disks appear to a local computer as a single disk, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metadata
Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive information about a resource. It is used for discovery and identification. It includes elements such as title, abstract, author, and keywords. * Structural metadata – metadata about containers of data and indicates how compound objects are put together, for example, how pages are ordered to form chapters. It describes the types, versions, relationships, and other characteristics of digital materials. * Administrative metadata – the information to help manage a resource, like resource type, permissions, and when and how it was created. * Reference metadata – the information about the contents and quality of statistical data. * Statistical metadata – also called process data, may describe processes that collect, process, or produce st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File Descriptor
In Unix and Unix-like computer operating systems, a file descriptor (FD, less frequently fildes) is a process-unique identifier (handle) for a file or other input/output resource, such as a pipe or network socket. File descriptors typically have non-negative integer values, with negative values being reserved to indicate "no value" or error conditions. File descriptors are a part of the POSIX API. Each Unix process (except perhaps daemons) should have three standard POSIX file descriptors, corresponding to the three standard streams: Overview In the traditional implementation of Unix, file descriptors index into a per-process maintained by the kernel, that in turn indexes into a system-wide table of files opened by all processes, called the . This table records the ''mode'' with which the file (or other resource) has been opened: for reading, writing, appending, and possibly other modes. It also indexes into a third table called the inode table that describes the actual u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAID
Raid, RAID or Raids may refer to: Attack * Raid (military), a sudden attack behind the enemy's lines without the intention of holding ground * Corporate raid, a type of hostile takeover in business * Panty raid, a prankish raid by male college students on the living quarters of female students to steal panties as trophies * Police raid, a police action involving the entering of a house with the intent to capture personnel or evidence, often taking place early in the morning *Union raid, when an outsider trade union takes over the membership of an existing union Arts, entertainment, and media Films * ''Raid'' (1947 film), an East German film * ''Raid'' (2003 film), a 2003 Finnish film * ''Raid'' (2018 film), an Indian period crime thriller Gaming * Raid (gaming), a type of mission in a video game where a large number of people combine forces to defeat a powerful enemy * ''Raid'' (video game), a Nintendo Entertainment System title released by Sachen in 1989 * '' Raid over Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metadata
Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive information about a resource. It is used for discovery and identification. It includes elements such as title, abstract, author, and keywords. * Structural metadata – metadata about containers of data and indicates how compound objects are put together, for example, how pages are ordered to form chapters. It describes the types, versions, relationships, and other characteristics of digital materials. * Administrative metadata – the information to help manage a resource, like resource type, permissions, and when and how it was created. * Reference metadata – the information about the contents and quality of statistical data. * Statistical metadata – also called process data, may describe processes that collect, process, or produce st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Load Balancing (computing)
In computing, load balancing is the process of distributing a set of tasks over a set of resources (computing units), with the aim of making their overall processing more efficient. Load balancing can optimize the response time and avoid unevenly overloading some compute nodes while other compute nodes are left idle. Load balancing is the subject of research in the field of parallel computers. Two main approaches exist: static algorithms, which do not take into account the state of the different machines, and dynamic algorithms, which are usually more general and more efficient but require exchanges of information between the different computing units, at the risk of a loss of efficiency. Problem overview A load-balancing algorithm always tries to answer a specific problem. Among other things, the nature of the tasks, the algorithmic complexity, the hardware architecture on which the algorithms will run as well as required error tolerance, must be taken into account. Therefore c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Address Redundancy Protocol
The Common Address Redundancy Protocol or CARP is a computer networking protocol which allows multiple hosts on the same local area network to share a set of IP addresses. Its primary purpose is to provide failover redundancy, especially when used with firewalls and routers. In some configurations, CARP can also provide load balancing functionality. CARP provides functionality similar to Virtual Router Redundancy Protocol (VRRP) and to Cisco Systems' Hot Standby Router Protocol (HSRP). It is implemented in several BSD-based operating systems and has been ported to Linux (ucarp). Example If there is a single computer running a packet filter, and it goes down, the networks on either side of the packet filter can no longer communicate with each other, or they communicate without any packet filtering. If, however, there are two computers running a packet filter, running CARP, then if one fails, the other will take over, and computers on either side of the packet filter will not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Cluster
A computer cluster is a set of computers that work together so that they can be viewed as a single system. Unlike grid computers, computer clusters have each node set to perform the same task, controlled and scheduled by software. The components of a cluster are usually connected to each other through fast local area networks, with each node (computer used as a server) running its own instance of an operating system. In most circumstances, all of the nodes use the same hardware and the same operating system, although in some setups (e.g. using Open Source Cluster Application Resources (OSCAR)), different operating systems can be used on each computer, or different hardware. Clusters are usually deployed to improve performance and availability over that of a single computer, while typically being much more cost-effective than single computers of comparable speed or availability. Computer clusters emerged as a result of convergence of a number of computing trends including t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storage Area Network
A storage area network (SAN) or storage network is a computer network which provides access to consolidated, block-level data storage. SANs are primarily used to access data storage devices, such as disk arrays and tape libraries from servers so that the devices appear to the operating system as direct-attached storage. A SAN typically is a dedicated network of storage devices not accessible through the local area network (LAN). Although a SAN provides only block-level access, file systems built on top of SANs do provide file-level access and are known as shared-disk file systems. Newer SAN configurations enable hybrid SAN and allow traditional block storage that appears as local storage but also object storage for web services through APIs. Storage architectures Storage area networks (SANs) are sometimes referred to as ''network behind the servers'' and historically developed out of a centralized data storage model, but with its own data network. A SAN is, at its simp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Replication (computing)
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. Terminology Replication in computing can refer to: * ''Data replication'', where the same data is stored on multiple storage devices * ''Computation replication'', where the same computing task is executed many times. Computational tasks may be: ** ''Replicated in space'', where tasks are executed on separate devices ** ''Replicated in time'', where tasks are executed repeatedly on a single device Replication in space or in time is often linked to scheduling algorithms. Access to a replicated entity is typically uniform with access to a single non-replicated entity. The replication itself should be transparent to an external user. In a failure scenario, a failover of replicas should be hidden as much as possible with respect to quality of service. Computer scientis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partition (database)
A partition is a division of a logical database or its constituent elements into distinct independent parts. Database partitioning is normally done for manageability, performance or availability reasons, or for load balancing. It is popular in distributed database management systems, where each partition may be spread over multiple nodes, with users at the node performing local transactions on the partition. This increases performance for sites that have regular transactions involving certain views of data, whilst maintaining availability and security. Partitioning criteria Current high-end relational database management systems provide for different criteria to split the database. They take a ''partitioning key'' and assign a partition based on certain criteria. Some common criteria include: * Range partitioning: selects a partition by determining if the partitioning key is within a certain range. An example could be a partition for all rows where the "zipcode" column has a val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Computing
A distributed system is a system whose components are located on different computer network, networked computers, which communicate and coordinate their actions by message passing, passing messages to one another from any system. Distributed computing is a field of computer science that studies distributed systems. The components of a distributed system interact with one another in order to achieve a common goal. Three significant challenges of distributed systems are: maintaining concurrency of components, overcoming the clock synchronization, lack of a global clock, and managing the independent failure of components. When a component of one system fails, the entire system does not fail. Examples of distributed systems vary from service-oriented architecture, SOA-based systems to massively multiplayer online games to peer-to-peer, peer-to-peer applications. A computer program that runs within a distributed system is called a distributed program, and ''distributed programming' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
