Amoeba is a

distributed operating system A distributed operating system is system software over a collection of independent software, networked, communicating, and physically separate computational nodes. They handle jobs which are serviced by multiple CPUs. Each individual node holds a ...

developed by

Andrew S. Tanenbaum Andrew Stuart Tanenbaum (born March 16, 1944), sometimes referred to by the handle ast, is an American-Dutch computer scientist and professor emeritus of computer science at the Vrije Universiteit Amsterdam in the Netherlands. He is the author ...

and others at the

Vrije Universiteit Amsterdam The Vrije Universiteit Amsterdam (abbreviated as ''VU Amsterdam'' or simply ''VU'' when in context) is a public research university in Amsterdam, Netherlands, being founded in 1880. The VU Amsterdam is one of two large, publicly funded research ...

. The aim of the Amoeba project was to build a

timesharing In computing, time-sharing is the sharing of a computing resource among many users at the same time by means of multiprogramming and multi-tasking.DEC Timesharing (1965), by Peter Clark, The DEC Professional, Volume 1, Number 1 Its emergence ...

system that makes an entire network of computers appear to the user as a single machine. Development at the Vrije Universiteit was stopped: the source code of the latest version (5.3) was last modified on 30 July 1996. The

Python programming language Python is a high-level, general-purpose programming language. Its design philosophy emphasizes code readability with the use of significant indentation. Python is dynamically-typed and garbage-collected. It supports multiple programming p ...

was originally developed for this platform.

Overview

The goal of the Amoeba project was to construct an operating system for networks of computers that would present the network to the user as if it were a single machine. An Amoeba network consists of a number of

workstation 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 ''workst ...

s connected to a "pool" of processors, and executing a program from a terminal causes it to run on any of the available processors, with the operating system providing load balancing. Unlike the contemporary Sprite, Amoeba does not support

process migration In computing, process migration is a specialized form of process management whereby processes are moved from one computing environment to another. This originated in distributed computing, but is now used more widely. On multicore machines (multip ...

.Fred Douglis, M. Frans Kaashoek, Andrew S. Tanenbaum and

John Ousterhout John Kenneth Ousterhout (, born October 15, 1954) is a professor of computer science at Stanford University. He founded Electric Cloud with John Graham-Cumming. Ousterhout was a professor of computer science at University of California, Berkeley ...

(1991)
A comparison of two distributed systems: Amoeba and Sprite
Computing Systems 4(4), pp. 353–384. The workstations would typically function as networked terminals only. Aside from workstations and processors, additional machines operate as

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

s for files, directory services,

TCP/IP The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the su ...

communications etc.

, M. Frans Kaashoek, Robbert van Renesse and Henri E. Bal (1991)
The Amoeba distributed operating system — a status report
Computer Communications 14. Amoeba is a

microkernel In computer science, a microkernel (often abbreviated as μ-kernel) is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, ...

-based operating system. It offers multithreaded programs and a

remote procedure call In distributed computing, a remote procedure call (RPC) is when a computer program causes a procedure ( subroutine) to execute in a different address space (commonly on another computer on a shared network), which is coded as if it were a normal ...

(RPC) mechanism for communication between threads, potentially across the network; even kernel-threads use this RPC mechanism for communication. Each thread is assigned a 48-bit number called its "port", which serves as its unique, network-wide "address" for communication. The user interface and APIs of Amoeba were modeled after

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, ...

and compliance with the

POSIX The Portable Operating System Interface (POSIX) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines both the system- and user-level application programming in ...

standard was partially implemented; some of the Unix emulation code consists of utilities ported over from Tanenbaum's other operating system, MINIX. Early versions used a "homebrew" window system, which the Amoeba authors considered "faster ... in our view, cleaner ... smaller and much easier to understand", but version 4.0 uses the

X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting wi ...

(and allows

X terminal In computing, an X terminal is a display/input terminal for X Window System client applications. X terminals enjoyed a period of popularity in the early 1990s when they offered a lower total cost of ownership alternative to a full Unix workst ...

s as terminals). The system uses FLIP as a network protocol.

References

External links

Amoeba home page (static page, ftp links are dead)

FSD-Amoeba page at Sourceforge (file downloads give 403 errors)

ArchiveOS mirror of Amoeba 5.3
{{Microkernel Microkernel-based operating systems Distributed computing architecture Distributed operating systems Computer science in the Netherlands Information technology in the Netherlands Microkernels

Overview

See also

References

External links