A super-server, sometimes called a service dispatcher, is a type of

daemon A demon is a malevolent supernatural being, evil spirit or fiend in religion, occultism, literature, fiction, mythology and folklore. Demon, daemon or dæmon may also refer to: Entertainment Fictional entities * Daemon (G.I. Joe), a character ...

run generally on

Unix-like A Unix-like (sometimes referred to as UN*X, *nix or *NIX) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Uni ...

systems.

Usage

A super-server starts other

server Server may refer to: Computing *Server (computing), a computer program or a device that provides requested information for other programs or devices, called clients. Role * Waiting staff, those who work at a restaurant or a bar attending custome ...

s when needed, normally with access to them checked by a

TCP wrapper __NOTOC__ TCP Wrappers (also known as tcp_wrappers) is a host-based networking ACL system, used to filter network access to Internet Protocol servers on (Unix-like) operating systems such as Linux or BSD. It allows host or subnetwork IP addresse ...

. It uses very few resources when in idle state. This can be ideal for

workstations A workstation is a special computer designed for technical or scientific applications. Intended primarily to be used by a single user, they are commonly connected to a local area network and run multi-user operating systems. The term ''workstat ...

used for local

web development Web development is the work involved in developing a website for the Internet (World Wide Web) or an intranet (a private network). Web development can range from developing a simple single static page of plain text to complex web applications, ...

, client/server development or low-traffic daemons with occasional usage (such as ident and

SSH The Secure Shell Protocol (SSH Protocol) is a cryptographic network protocol for operating network services securely over an unsecured network. Its most notable applications are remote login and command-line execution. SSH was designed for Un ...

Performance

The creation of an operating system process embodying the sub-daemon is deferred until an incoming connection for the sub-daemon arrives. This results in a delay to the handling of the connection (in comparison to a connection handled by an already-running process). Whether this delay is incurred repeatedly for every incoming connection depends on the design of the particular sub-daemon; simple daemons usually require a separate sub-daemon instance (i.e. a distinct, separate operating system process) be started for each and every incoming connection. Such a request-per-process design is more straightforward to implement, but for some workloads, the extra CPU and memory overhead of starting multiple operating system processes may be undesirable. Alternatively, a single sub-daemon operating system process can be designed to handle multiple connections, allowing similar performance to a "stand alone"

(except for the one-off delay for the first connection to the sub-daemon).

Implementations

inetd inetd (internet service daemon) is a super-server Daemon (computer software), daemon on many Unix systems that provides Internet services. For each configured service, it listens for requests from connecting clients. Requests are served by spawn ...

launchd launchd is an init and operating system service management daemon created by Apple Inc. as part of macOS to replace its BSD-style init and SystemStarter. There have been efforts to port launchd to FreeBSD and derived systems. Components Th ...

systemd systemd is a software suite that provides an array of system components for Linux operating systems. The main aim is to unify service configuration and behavior across Linux distributions. Its primary component is a "system and service manage ...

ucspi-tcp ucspi-tcp is a public domain Unix TCP command-line tool for building TCP client-server applications. It consists of super-server ''tcpserver'' and ''tcpclient'' application. Fro"Life with qmail" Dave Sill, 2 January 200 ''ucspi-tcp'' is an acr ...

xinetd In computer networking, xinetd (''Extended Internet Service Daemon'') is an open-source software, open-source super-server Daemon (computer software), daemon which runs on many Unix-like operating system, systems, and manages Internet-based conne ...

References

{{Network-software-stub Internet Protocol based network software Servers (computing)