Server

of these articles acts of the software. For physical servers (hardware), see host (information technology).

A server is a program, which on the establishment of contact of a Client - program waits and after establishment of contact with this message exchanges.

remarks

communication take place thereby after the Client server system. In the information technology an alternative to the Client server principle is the Peer ton Peer - principle.

The rules, those the format as well as thoseMeaning of the messages exchanged between servers and Client determine, call one minutes.

One calls the hardware, on which one or more servers run, host.

The term server is colloquially also often used, around computers in oneTo designate computer network, on which applications of servers one implements.

availability and Clustering

a server run either permanently (daemon mode) or on request of a Clients are started (see. inetd). Around the reliability and efficiency tooincrease, can several servers as cluster be hooked up. These can be distributed both on one and on several host. Breaks in or if several servers fail, then the still existing servers take over the inquiry of the Clients.

Examples

• server, which the HTTP - minutes implement, HTTP servers are called. An access is made by HTTP Clients. HTTP is used particularly by the World Wide Web (WWW). HTTPS is a variant of HTTP, with which log data will coded transfer.
• Server,one minutes for file transmission implement, as file, data or file servers are generally designated. The most frequently used file transmission protocols are ftp, SFTP, NFS and SMB/CIFS.

further examples

• of means print servers (printers - servers) receiveUser access to distant printers.
• By means of time servers (time server, network TimeProtocol - servers) computer clocks are synchronized.
• Mailserver (E-Mail server) and new servers serve communication.
• Root servers are the most important name servers of the Domain Name of system.
• Backup - server, those archivingthe volume of data administer.
• On play servers (Gameservern) several players can play together or against each other.
• With a Streaming server one can radiate for example Internet radio.
• Data base servers administer one or more data base systems.
• emulated server systems are more vServer. Run several more vServer on a server.
• Web serverare server services, which the HTTP - minutes on a computer make available.
• A pro XY server puts information other computers to buffered at the disposal.
• A file transfer service makes the transmission of files possible between computers. Most well-known and usually-used TCP/IP minutes at all are ftp.
• File access service and/or. Network File System permits a working on of distant files over a Client. Generally also competitive accesses are possible. Contrary to a file transfer service become not the entire files, but only the operations applied to the files andthe pertinent data transmit. Well-known services are for example NFS, SMB.

literature

• Douglas E. Comer: Computer networks and Internets. Pearson study, ISBN 3-8273-7023-X
• Craig Hunt: TCP/IP. O' Reilly, ISBN 3-89721-179-3
• Hans's Robert Hansen, Gustaf Neumann: Work book economical informatics.6. Aufl. UTB, Stuttgart 2002, ISBN 3825212815