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Über dieses Buch

In general, distributed systems can be classified into Distributed File Systems (DFS) and Distributed Operating Systems (DOS). The survey which follows distinguishes be­ tween DFS approaches in Chapters 2-3, and DOS approaches in Chapters 4-5. Within DFS and DOS, I further distinguish "traditional" and object-oriented approaches. A traditional approach is one where processes are the active components in the systems and where the name space is hierarchically organized. In a centralized environment, UNIX would be a good example of a traditional approach. On the other hand, an object-oriented approach deals with objects in which all information is encapsulated. Some systems of importance do not fit into the DFS/DOS classification. I call these systems "closely related" and put them into Chapter 6. Chapter 7 contains a table of comparison. This table gives a lucid overview summarizing the information provided and allowing for quick access. The last chapter is added for the sake of completeness. It contains very brief descriptions of other related systems. These systems are of minor interest or do not provide transparency at all. Sometimes I had to assign a system to this chapter simply for lack of adequate information about it.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction

Abstract
This book is yet another survey of distributed systems.1 However, I believe that this approach is novel. For one thing, I have tried, to the best of my knowledge, to include the majority of the distributed file and operating systems presently in existence or of historical interest. For another, the approach is encyclopedic. Each system is described independently. A description of both the main goal and the pros and cons (advantages and disadvantages) of each system enables the reader to decide whether or not a system is of interest to him or her.
Uwe M. Borghoff

Chapter 2. Traditional Distributed File Systems

Abstract
The primary purpose of Alpine (known within Xerox as Research Alpine or rAlpine) is to store database files. Its secondary goal is to provide transparent access to ordinary files, such as documents, programs, and the like.
Uwe M. Borghoff

Chapter 3. Object-Oriented Distributed File Systems

Abstract
The DOMAIN system is mainly a distributed file system where an object-oriented approach is taken. It is a commercial product of Apollo Computers, Inc., that connects personal workstations and server computers. All processors transparently share a common network-wide virtual memory system that allows groups of users to share programs, files and peripherals.
Uwe M. Borghoff

Chapter 4. Traditional Distributed Operating Systems

Abstract
Accent is a successor to the RIG system (Sect. 8.54), a message-based network access machine. It tries to solve the problems of transparent access, failure notification, protection and access to large objects (for example files) with low message overhead. Also, it provides location and failure transparency.
Uwe M. Borghoff

Chapter 5. Object-Oriented Distributed Operating Systems

Abstract
Alpha is a non-proprietary operating system for providing system and mission level resource management in large, complex, distributed real-time systems. The most demanding examples of such systems are always found first in military contexts (such as combat platform mission management and battle management), but similar needs subsequently arise in aerospace (such as space stations, autonomous exploration vehicles, and air traffic control) and civilian industry (such as factory automation, telecommunications, and OLTP).
Uwe M. Borghoff

Chapter 6. Closely Related Systems

Abstract
Athena is a joint project of the Massachusetts Institute of Technology (MIT), DEC and IBM to explore the potential uses of advanced computer technology in the university curriculum.
Uwe M. Borghoff

Chapter 7. Table of Comparison

Abstract
The table of comparison is given to summarize and compare the systems discussed. It should be viewed carefully, since in certain ways any categorized comparison can be misleading. However, this way an easy-to-read overview may be obtained. The table provides quick access to a large amount of highly condensed information. The entries are organized according to the criteria used to describe the systems. Sometimes, a similar issue or a comparable feature for an entry have been implemented. I mark this with a special symbol ‘+’. Entries put in brackets indicate an issue not yet implemented but planned, or indicate an optional feature.
Uwe M. Borghoff

Chapter 8. Related Projects

Abstract
In this chapter I present a list of related projects which are not described in the survey. The list contains a short description of and at least a main reference to each project.
Uwe M. Borghoff

Backmatter

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