Distributed Computing Software Project

2003

Nowadays the term of a "service" is frequently used in the discipline of modelling distributed system. However, it seems that the meaning of a service varies, depending on the domain it is used in. In this article we describe what various perceptions of the term "service" have in common and derive a formally founded definition of services that helps to

Oops Messenger, 1993

Modern computer hardware technology allows a single architecture to be used for a range of machines from supercomputers to toasters. Hardware designers have recognized that an architecture should be scalable and system software developers must address the same issue. Scalability means that the architecture must be flexible enough to satisfy diverse hardware and application needs. The key to operating system flexibility is to base the architecture on a high-level graph model and to use the generalized object model and metacomputing. The resulting framework is a uniform object model for application and system software. Classically, operating system flexibility means that the architecture must handle various processor capabilities, differing memory and disk sizes and a vast range of peripheral devices. Today, it also includes dealing with multiprocessor systems, diverse network topologies and multimedia input/output. In the future, as radio-based networking becomes common, changes will be dynamic, requiring the flexible operating system to adapt as elements of a distributed system move into and out of range. Different classes of applications have different requirements. The valuable data managed by an OODB must be maintained over long periods of time while a multimedia application requires guaranteed bandwidth. The necessary services and the relative emphasis on different functionalities vary drastically.

1986

In this paper a logical model of a distributed operating system has been presented. This model of a distributed operating system contains a set of processes managing resources, connections between these processes, and mappings of events controlling this distributed operating system into processes managing resources. The fundamental types of resources introduced by the architecture of local computer networks, i.e., messages and data structures describing the location of resources in the network, have been defined. Operations on these resources and connections between the processes managing them and processes managing other resources of the distributed operating system have been presented. Addressing processes have been discussed. The model has been constructed in such a way that a synthesis of different simulation tools (models) to study distributed operating systems can be carried out. In particular, this model makes it possible to construct simulation tools to study the effectiveness of distributed operating systems with processes managing resources defined in different ways.That means that the model has been developed in such a way to be both a concept and a tool like the model developed by A. K. Jones. The later was treated by us as a background model.

Computer Communications, 1992

compare software design approaches for distributed computing systems, and discuss the future trends Due to the rapid development of computer, communication and microelectronics technologies, the trend of distributed computing systems is to become more distributed. Because the characteristics of distributed computing systems are significantly different from those of traditional computing systems, different approaches are needed to effectively address the design issues related to the characteristics of software for distributed computing systems. In this paper, the methods currently used to develop the software for distributed computing systems are classified into three approaches: dataflow-oriented; communication-oriented; and object-oriented. Their applicabilities to various applications for distributed computing systems are discussed, and object-oriented approach is identified as a more promising approach to developing distributed software. The future trends and research directions of software development techniques for distributed computing systems are discussed. Keywords: software design methods, distributed computing systems, dataflow-oriented approach, communicationoriented approach, object-oriented approach Due to the rapid development of computer, communication and microelectronics technologies, the trend of computing systems is to become more distributed to realize the advantage of matching the computing system structures with those of the problems for various applications. Furthermore, distributed computing systems have

2008

We propose a motivation from "first principles" of a small set of abstractions for expressing and analyzing service based systems. In particular, we suggest the aspects of distribution, process delegation, communication and context sensitiveness, and loose coupling as specific to the service-oriented computational model. Distinguishing aspects of our model are the adoption of a very simple, context sensitive, message-passing local communication mechanism, and a novel mechanism for handling exceptional behavior. We instantiate our model by extending of a fragment of the π-calculus, and show that behavioral equivalences, defined by strong bisimilarity and weak bisimilarity, are congruences for all operators.

Software - Practice and Experience, 1988

This article analyses the structure of the distributed operating system of the SMD project -DIOS.

The purpose of this paper is to present some preliminary results of a research activity carried on at CSELT on the definition and prototype implementation of a distributed processing environment, based on the ODP Reference Model, . In particular we concentrate here on the computational and engineering viewpoints.

Lecture Notes in Computer Science, 2012

The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.

ACM Computing Surveys, 1985

Distributed operating systems have many aspects in common with centralized ones, but they also differ in certain ways. This paper is intended as an introduction to distributed operating systems, and especially to current university research about them. After a discussion of what constitutes a distributed operating system and how it is distinguished from a computer network, various key design issues are discussed. Then several examples of current research projects are examined in some detail, namely, the Cambridge Distributed Computing System, Amoeba, V, and Eden.

Annals of Faculty …, 2011

Software applications may have different degrees of complexity depending on the problems they try to solve and can integrate very complex elements that bring together functionality that sometimes are competing or conflicting. We can take for example a mobile communications system. Functionalities of such a system are difficult to understand, and they add to the nonfunctional requirements such as the use in practice, performance, cost, durability and security. The transition from local computer networks to cover large networks that allow millions of machines around the world at speeds exceeding one gigabit per second allowed universal access to data and design of applications that require simultaneous use of computing power of several interconnected systems. The result of these technologies has enabled the evolution from centralized to distributed systems that connect a large number of computers. To enable the exploitation of the advantages of distributed systems one had developed software and communications tools that have enabled the implementation of distributed processing of complex solutions. The objective of this document is to present all the hardware, software and communication tools, closely related to the possibility of their application in integrated social and economic level as a result of globalization and the evolution of e-society. These objectives and national priorities are based on current needs and realities of Romanian society, while being consistent with the requirements of Romania's European orientation towards the knowledge society, strengthening the information society, the target goal representing the accomplishment of e-Romania, with its strategic e-government component. Achieving this objective repositions Romania and gives an advantage for sustainable growth, positive international image, rapid convergence in Europe, inclusion and strengthening areas of high competence, in line with Europe 2020, launched by the European Council in June 2010.