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Timestamping (computing)
In computing, timestamping refers to the use of an electronic timestamp to provide a temporal order among a set of events. Timestamping techniques are used in a variety of computing fields, from network management and computer security Computer security (also cybersecurity, digital security, or information technology (IT) security) is a subdiscipline within the field of information security. It consists of the protection of computer software, systems and computer network, n ... to concurrency control.''Computer aided verification: 13th International conference'', by Gérard Berry, Hubert Comon, A. Finkel 2001 page 423 For instance, a heartbeat network uses timestamping to monitor the nodes on a high availability computer cluster.''Theoretical Aspects of Distributed Computing in Sensor Networks'' by Sotiris Nikoletseas and José D.P. Rolim 2011 page 304 Timestamping computer files (updating the timestamp in the per-file metadata every time a file is modified) make ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, hardware and software. Computing has scientific, engineering, mathematical, technological, and social aspects. Major computing disciplines include computer engineering, computer science, cybersecurity, data science, information systems, information technology, and software engineering. The term ''computing'' is also synonymous with counting and calculation, calculating. In earlier times, it was used in reference to the action performed by Mechanical computer, mechanical computing machines, and before that, to Computer (occupation), human computers. History The history of computing is longer than the history of computing hardware and includes the history of methods intended for pen and paper (or for chalk and slate) with or without the aid of tables. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timestamp
A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second. Timestamps do not have to be based on some absolute notion of time, however. They can have any epoch, can be relative to any arbitrary time, such as the power-on time of a system, or to some arbitrary time in the past. A distinction is sometimes made between the terms datestamp, timestamp and date-timestamp: * Datestamp or DS: A date, for example -- according to ISO 8601 * Timestamp or TS: A time of day, for example :: using 24-hour clock * Date-timestamp or DTS: Date and time, for example --, :: History The term "timestamp" derives from rubber stamps used in offices to stamp the current date, and sometimes time, in ink on paper documents, to record when the document was received. Common examples of this type of timestamp are a postmark on a letter or the "in" and "out" times on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Management
Network management is the process of administering and managing computer networks. Services provided by this discipline include fault analysis, performance management, provisioning of networks and maintaining quality of service. Network management software is used by network administrators to help perform these functions. Technologies A small number of accessory methods exist to support network and network device management. Network management allows IT professionals to monitor network components within large network area. Access methods include the SNMP, command-line interface (CLI), custom XML, CMIP, Windows Management Instrumentation (WMI), Transaction Language 1 (TL1), CORBA, NETCONF, RESTCONF and the Java Management Extensions (JMX). Schemas include the Structure of Management Information (SMI), YANG, WBEM, the Common Information Model ( CIM Schema), and MTOSI amongst others. Value Effective network management can provide positive strategic impacts. For ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Security
Computer security (also cybersecurity, digital security, or information technology (IT) security) is a subdiscipline within the field of information security. It consists of the protection of computer software, systems and computer network, networks from Threat (security), threats that can lead to unauthorized information disclosure, theft or damage to computer hardware, hardware, software, or Data (computing), data, as well as from the disruption or misdirection of the Service (economics), services they provide. The significance of the field stems from the expanded reliance on computer systems, the Internet, and wireless network standards. Its importance is further amplified by the growth of smart devices, including smartphones, televisions, and the various devices that constitute the Internet of things (IoT). Cybersecurity has emerged as one of the most significant new challenges facing the contemporary world, due to both the complexity of information systems and the societi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concurrency Control
In information technology and computer science, especially in the fields of computer programming, operating systems, multiprocessors, and databases, concurrency control ensures that correct results for concurrent operations are generated, while getting those results as quickly as possible. Computer systems, both software and hardware, consist of modules, or components. Each component is designed to operate correctly, i.e., to obey or to meet certain consistency rules. When components that operate concurrently interact by messaging or by sharing accessed data (in memory or storage), a certain component's consistency may be violated by another component. The general area of concurrency control provides rules, methods, design methodologies, and theories to maintain the consistency of components operating concurrently while interacting, and thus the consistency and correctness of the whole system. Introducing concurrency control into a system means applying operation constraints ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heartbeat Network
In computer science, a heartbeat is a periodic signal generated by hardware or software to indicate normal operation or to synchronize other parts of a computer system. Heartbeat mechanism is one of the common techniques in mission critical systems for providing high availability and fault tolerance of network services by detecting the network or systems failures of nodes or daemons which belongs to a network cluster—administered by a master server—for the purpose of automatic adaptation and rebalancing of the system by using the remaining redundant nodes on the cluster to take over the load of failed nodes for providing constant services. Usually a heartbeat is sent between machines at a regular interval in the order of seconds; a heartbeat message. If the endpoint does not receive a heartbeat for a time—usually a few heartbeat intervals—the machine that should have sent the heartbeat is assumed to have failed. Heartbeat messages are typically sent non-stop on a ... [...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 newest manifestation of cluster computing is cloud computing. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stat (system Call)
is a Unix system call that queries the file system for metadata about a file (including special files such as directories). The metadata contains many fields including type, size, ownership, permissions and timestamps. For example, the command uses this system call to retrieve timestamps: * mtime: when last modified () * atime: when last accessed () * ctime: when last status changed () appeared in Version 1 Unix. It is among the few original Unix system calls to change, with Version 4's addition of group permissions and larger file size. Since at least 2004, the same-named shell command stat has been available for Linux to expose features of the system call via a command-line interface. Functions The C POSIX library header , found on POSIX and other Unix-like operating systems, declares stat() and related functions. int stat(const char *path, struct stat *buf); int lstat(const char *path, struct stat *buf); int fstat(int filedesc, struct stat *buf); Each ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Build Automation
Build automation is the practice of building software systems in a relatively unattended fashion. The build is configured to run with minimized or no software developer interaction and without using a developer's personal computer. Build automation encompasses the act of configuring the build system as well the resulting system itself. Build automation encompasses both sequencing build operations via non-interactive interface tools and running builds on a shared server. Tools Build automation tools allow for sequencing the tasks of building software via a non-interactive interface. Existing tools such as Make can be used via custom configuration file or using the command-line. Custom tools such as shell scripts can also be used, although they become increasingly cumbersome as the codebase grows more complex. Some tools, such as shell scripts, are task-oriented declarative programming. They encode sequences of commands to perform with usually minimal conditional logic. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trusted Timestamping
Trusted timestamping is the process of computer security, securely keeping track of the creation and modification time of a document. Security here means that no one—not even the owner of the document—should be able to change it once it has been recorded provided that the timestamper's integrity is never compromised. The administrative aspect involves setting up a publicly available, trusted timestamp management infrastructure to collect, process and renew timestamps. History The idea of timestamping information is centuries old. For example, when Robert Hooke discovered Hooke's law in 1660, he did not want to publish it yet, but wanted to be able to claim priority. So he published the anagram ''ceiiinosssttuv'' and later published the translation ''ut tensio sic vis'' (Latin for "as is the extension, so is the force"). Similarly, Galileo Galilei, Galileo first published his discovery of the phases of Venus in the anagram form. Sir Isaac Newton, in responding to questions f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timestamp-based Concurrency Control
In computer science, a timestamp-based concurrency control algorithm is a optimistic concurrency control method. It is used in some databases to safely handle transactions using timestamps. Operation Assumptions * Every timestamp value is unique and accurately represents an instant in time. * A higher-valued timestamp occurs later in time than a lower-valued timestamp. Generating a timestamp A number of different approaches can generate timestamps * Using the value of the system's clock at the start of a transaction as the timestamp. * Using a thread-safe shared counter that is incremented at the start of a transaction as the timestamp. * A combination of the above two methods. Formal definition Each transaction (T_i) is an ordered list of actions (A_). Before the transaction performs its first action (A_), it is marked with the current timestamp, or any other strictly totally ordered sequence: TS(T_i) = NOW(). Every transaction is also given an initially empty set of transacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
