Server (computing)

This product was added to computer science because of the content, defects on the quality assurance side of the editor. This is done to bring the quality of the articles from the computer science subject area to an acceptable level. Help us to eliminate the substantive shortcomings of this article and take part you in the discussion! ( ) Reason: As is handled here with the term server I think this is nonsense: Server > waiters and Dedicated > Dedicated, but the statement referred to rather decidedly. Virtual in the sense of computer network / computer cluster but not in the sense of virtual private server (VPS ), but then there are again shared server? What does a objekttiv measurable and explainable difference to do with advertising? - Peter Littmann (Talk ) 20:46 22 Feb. 2014 ( CET )

The misleading reference to the waiter I have removed and cleaned the introductory phrase; the rest of the review is still to edit. - Herbert Klaeren (Talk ) 10:36 28 Feb. 2014 ( CET )

A server is a computer program or a computer for access to a centralized resource or service in a network:

  • A server (software) is a program that is in the client -server model with a different program, the client (English for client) communicates to give him access to special services.
  • A server (hardware ) is a computer on which to run one or more server (software).

For the server hardware, the term host is used in technical language.

The ambiguity of the term server is further explained and discussed in the following section.

  • 2.1 Virtual Server
  • 2.2 Dedicated Server
  • 2.3 Shared Server

Ambiguity

History of the server - term

When the first server programmed, were the computers on which they are installed, referred to as a host (see, host terminal principle). At that time almost exclusively hosts special powerful computer ( mainframe ). With the increasing power of standard computers certain server services could also be provided by them and thus came into the light of a broader public. However, this perceived only the computer on which the server software running. Therefore, the name server extended by the software on the hardware, on the host from. This conceptualization was acquired in advertising for computer hardware and also of journals, what the term established very quickly in the vernacular.

This ambiguity present in some cases leads to confusion because the name server is often used in a form in which for the layman is especially difficult to see whether the hardware or software aspect is meant.

Evolution of host and server

The term host is used at an early stage in the computer in the 1960s in connection with mainframes or mid-range systems and there usual time-sharing or multi-user operating systems. These systems are highly structured and essentially consist of a central processing unit, which is also known as the host and all the "intelligence" of houses, and the "dumb" terminals that are used only as a user terminal in the workplace and in practice only for input and output of data are used. The frequently used as a synonym expression server is more recent and comes from the field of personal computers and operating systems such as Banyan Vines, Mac OS, Netware or Unix. As the networking of these computers class virtually anywhere found its way at the end of the 1980s, they sought to distinguish it from the existing host - based architectures, an alternative designation and established this, the term server, as a representative example here is the dedicated NetWare server called. The architecture on the basis of personal computers typically have no "intelligent" hosts in contrast to "dumb" terminals, in this case, each system is "intelligence" provided with more or less. In this context, computer systems ( hardware and software), which is essentially other systems provide services (see: "Server (software) " ), called a server. In the Unix environment, differentiation is apparent at this time; here are (usually graphical ) workstations and workstation operating systems and their software (mostly console -based ) distinction servers and server operating systems and associated software. However, by now are both expressions - at least colloquially and in connection with hardware - practically synonymous.

Server as a term for software / client-server concept

A server (Latin for " Provider") is a program that provides a service (Service ). As part of the client-server model, a different program, the client ( customer " ), use this service. Clients and servers can be run as programs on different computers or on the same computer.

The server is ready to respond at any time to contact a client can. The rules of communication (format, call the server and the meaning of exchanged between server and client data), called protocol and are each defined for a service.

In general, the concept can be extended to a group of servers that offers a set of services. Examples: mail server (extended ) web server, application server, database server.

In practice, since servers usually collected run on specific machines, it has become common to refer to this computer as a server itself. The same examples: mail server, web server or application server.

In the parlance of software servers and clients, it has become, this attribute the skills that are actually provided by the hardware. So does this language use, for example, the client software with the server software contact, although it is capable to only by the hardware. So you completely abstracted from the way how the connection is technically realized, and which and how many computers are involved in this result. Thus, for example, both located on the same computer be connected via a cable or over the Internet.

Server as a term for hardware

The term server as hardware is used:

  • When referring to a computer whose hardware is designed for server applications, and partly by specific service areas (eg, high I / O throughput, large memory, many CPUs, high reliability, yet insignificant graphics performance ).
  • Server farm
  • Server Rack
  • Blade Server

The monitoring and maintenance of a server is an important activity in any organization dar. often used to come here so-called network monitoring systems.

Molding

Virtual Server

The simplest case of a server is the one where on a host server software is installed exactly.

If the performance of a single host is not sufficient to cope with the tasks of a server, you can connect several hosts to form a composite, which is also called computer clusters. For this purpose, a software is installed on all hosts that causes this represents clusters towards the clients as a single server. The user who is connected via its client with the server remains hidden there which host executes what part of his order. The server then it is a distributed system.

There is also the opposite case, in which a plurality of server software installed on a most efficient host. The users remains hidden here is that the various services are handled in reality only a single host.

Both arrangements are referred to as virtual server. Must be distinguished between virtual hosts and virtual servers (software). There are different types of virtualization.

Dedicated Servers

A dedicated server is a server that is intended for a network service or more permanently operated services, and not for everyday tasks (Workstation) is utilized. In marketing, the term is used to suggest to the customer a certain exclusivity.

Shared Server

A shared server is a server that a client or a specific task is available not exclusive. In marketing, it is used to a cheap rate for a single customer to realize.

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