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Server Hog
{{citations needed, date=November 2013 A server hog is a user, program or system that places excessive load on a server such that the server performance as experienced by other clients is degraded, or such that the server itself is so heavily loaded that it fails to perform routine housekeeping for its own maintenance. History In the early years of time-sharing computer systems in the 1960s it was common for a single institutional mainframe to control many interactive terminals. In such an environment server lag is acutely perceived. Furthermore, in many operating environments, scarce server resources such as CPU-seconds were often metered and charged against the account of the user running the program. An unintentional server hog could prove extremely costly in financial terms. These programs were often called run-away programs or endless loops. Resource contention Server performance has many dimensions. Any subsystem that becomes excessively loaded can compromise the per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Server (computing)
In computing, a server is a piece of computer hardware or software (computer program) that provides functionality for other programs or devices, called " clients". This architecture is called the client–server model. Servers can provide various functionalities, often called "services", such as sharing data or resources among multiple clients, or performing computation for a client. A single server can serve multiple clients, and a single client can use multiple servers. A client process may run on the same device or may connect over a network to a server on a different device. Typical servers are database servers, file servers, mail servers, print servers, web servers, game servers, and application servers. Client–server systems are usually most frequently implemented by (and often identified with) the request–response model: a client sends a request to the server, which performs some action and sends a response back to the client, typically with a result or acknowledg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries a vast range of information resources and services, such as the inter-linked hypertext documents and applications of the World Wide Web (WWW), electronic mail, telephony, and file sharing. The origins of the Internet date back to the development of packet switching and research commissioned by the United States Department of Defense in the 1960s to enable time-sharing of computers. The primary precursor network, the ARPANET, initially served as a backbone for interconnection of regional academic and military networks in the 1970s to enable resource shari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Bot
An Internet bot, web robot, robot or simply bot, is a software application that runs automated tasks (scripts) over the Internet, usually with the intent to imitate human activity on the Internet, such as messaging, on a large scale. An Internet bot plays the client role in a client–server model whereas the server role is usually played by web servers. Internet bots are able to perform tasks, that are simple and repetitive, much faster than a person could ever do. The most extensive use of bots is for web crawling, in which an automated script fetches, analyzes and files information from web servers. More than half of all web traffic is generated by bots. Efforts by web servers to restrict bots vary. Some servers have a robots.txt file that contains the rules governing bot behavior on that server. Any bot that does not follow the rules could, in theory, be denied access to or removed from the affected website. If the posted text file has no associated program/software/app, then ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meow Wars
The Meow Wars were an early example of a flame war sent over Usenet which began in 1996 and ended circa 1998. Its participants were known as "Meowers".Bartlett, Jamie.A Life Ruin: Inside the Digital Underworld" - Excerpt from: '' The Dark Net: Inside the Digital Underworld'' posted by Penguin Random House UK to Medium.com. Version on Google Books: Melville House Publishing, June 2, 2015. , 9781612194905. Google Books pages discussing the Meow Wars (using "Meowers" to describe the participants) arPT29anPT30/ref> The war was characterized by posters from one newsgroup " crapflooding", or posting a large volume of nonsense messages, to swamp on-topic communication in other groups. Ultimately, the flame war affected many boards, with Roisin Kiberd writing in ''Motherboard'', a division of ''Vice'', that esoteric Internet vocabulary was created as a result of the Meow Wars. The wars began when some Harvard students, who had "colonized" an abandoned newsgroup for fans of Karl Malden, , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trojan Horse (computing)
In computing, a Trojan horse is any malware that misleads users of its true intent. The term is derived from the Ancient Greek story of the deceptive Trojan Horse that led to the fall of the city of Troy. Trojans generally spread by some form of social engineering; for example, where a user is duped into executing an email attachment disguised to appear innocuous (e.g., a routine form to be filled in), or by clicking on some fake advertisement on social media or anywhere else. Although their payload can be anything, many modern forms act as a backdoor, contacting a controller who can then have unauthorized access to the affected computer. Ransomware attacks are often carried out using a Trojan. Unlike computer viruses and worms, Trojans generally do not attempt to inject themselves into other files or otherwise propagate themselves. Use of the term It's not clear where or when the concept, and this term for it, was first used, but by 1971 the first Unix manual assumed its r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Worm
A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. It often uses a computer network to spread itself, relying on security failures on the target computer to access it. It will use this machine as a host to scan and infect other computers. When these new worm-invaded computers are controlled, the worm will continue to scan and infect other computers using these computers as hosts, and this behaviour will continue. Computer worms use recursive methods to copy themselves without host programs and distribute themselves based on the law of exponential growth, thus controlling and infecting more and more computers in a short time. Worms almost always cause at least some harm to the network, even if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer. Many worms are designed only to spread, and do not attempt to change the systems they pass through. However, as th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Virus
A computer virus is a type of computer program that, when executed, replicates itself by modifying other computer programs and inserting its own code. If this replication succeeds, the affected areas are then said to be "infected" with a computer virus, a metaphor derived from biological viruses. Computer viruses generally require a host program. The virus writes its own code into the host program. When the program runs, the written virus program is executed first, causing infection and damage. A computer worm does not need a host program, as it is an independent program or code chunk. Therefore, it is not restricted by the host program, but can run independently and actively carry out attacks. Virus writers use social engineering deceptions and exploit detailed knowledge of security vulnerabilities to initially infect systems and to spread the virus. Viruses use complex anti-detection/stealth strategies to evade antivirus software. Motives for creating viruses can inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denial-of-service Attack
In computing, a denial-of-service attack (DoS attack) is a cyber-attack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to a network. Denial of service is typically accomplished by flooding the targeted machine or resource with superfluous requests in an attempt to overload systems and prevent some or all legitimate requests from being fulfilled. In a distributed denial-of-service attack (DDoS attack), the incoming traffic flooding the victim originates from many different sources. More sophisticated strategies are required to mitigate this type of attack, as simply attempting to block a single source is insufficient because there are multiple sources. A DoS or DDoS attack is analogous to a group of people crowding the entry door of a shop, making it hard for legitimate customers to enter, thus disrupting trade. Criminal perpetrators of DoS attacks oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrashing (computer Science)
In computer science, thrashing occurs when a computer's virtual memory resources are overused, leading to a constant state of paging and page faults, inhibiting most application-level processing. This causes the performance of the computer to degrade or collapse. The situation can continue indefinitely until either the user closes some running applications or the active processes free up additional virtual memory resources. After completing initialization, most programs operate on a small number of code and data pages compared to the total memory the program requires. The pages most frequently accessed are called the working set. When the working set is a small percentage of the system's total number of pages, virtual memory systems work most efficiently and an insignificant amount of computing is spent resolving page faults. As the working set grows, resolving page faults remains manageable until the growth reaches a critical point. Then faults go up dramatically and the time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Client (computing)
In computing, a client is a piece of computer hardware or software that accesses a service made available by a server as part of the client–server model of computer networks. The server is often (but not always) on another computer system, in which case the client accesses the service by way of a network. A client is a computer or a program that, as part of its operation, relies on sending a request to another program or a computer hardware or software that accesses a service made available by a server (which may or may not be located on another computer). For example, web browsers are clients that connect to web servers and retrieve web pages for display. Email clients retrieve email from mail servers. Online chat uses a variety of clients, which vary on the chat protocol being used. Multiplayer video games or online video games may run as a client on each computer. The term "client" may also be applied to computers or devices that run the client software or users that use th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Page Table
A page table is the data structure used by a virtual memory system in a computer operating system to store the mapping between virtual addresses and physical addresses. Virtual addresses are used by the program executed by the accessing process, while physical addresses are used by the hardware, or more specifically, by the random-access memory (RAM) subsystem. The page table is a key component of virtual address translation that is necessary to access data in memory. Role of the page table In operating systems that use virtual memory, every process is given the impression that it is working with large, contiguous sections of memory. Physically, the memory of each process may be dispersed across different areas of physical memory, or may have been moved ( paged out) to secondary storage, typically to a hard disk drive (HDD) or solid-state drive (SSD). When a process requests access to data in its memory, it is the responsibility of the operating system to map the virtual addres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spooling
In computing, spooling is a specialized form of multi-programming for the purpose of copying data between different devices. In contemporary systems, it is usually used for mediating between a computer application and a slow peripheral, such as a printer. Spooling allows programs to "hand off" work to be done by the peripheral and then proceed to other tasks, or to not begin until input has been transcribed. A dedicated program, the spooler, maintains an orderly sequence of jobs for the peripheral and feeds it data at its own rate. Conversely, for slow ''input'' peripherals, such as a card reader, a spooler can maintain a sequence of computational jobs waiting for data, starting each job when all of the relevant input is available; see batch processing. The spool itself refers to the sequence of jobs, or the storage area where they are held. In many cases, the spooler is able to drive devices at their full rated speed with minimal impact on other processing. Spooling is a co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
