software testing is a very expensive and time consuming process. It can account for up to 50% of the total cost of the software development. distributedsystems.make software testing a daunting task. The research desc...
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ISBN:
(纸本)0769526551
software testing is a very expensive and time consuming process. It can account for up to 50% of the total cost of the software development. distributedsystems.make software testing a daunting task. The research described in this paper investigates a novel multi-agent framework for testing 3-tier. distributedsystems. This paper describes the framework architecture as well as the communication mechanism among agents in the architecture. Web-based application is examined as a case study to validate the proposed framework. The framework is considered as a step forward to automate testing for distributedsystems.in order to enhance their reliability within an acceptable range of cost and time.
This conference proceedings contains 81 papers, with 7 papers in abstract form only. Discussed are: software tool, software engineering environment, databasesystems.with special attention to management and distribute...
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ISBN:
(纸本)0818605502
This conference proceedings contains 81 papers, with 7 papers in abstract form only. Discussed are: software tool, software engineering environment, databasesystems.with special attention to management and distributedsystems. concurrency control, quality through software engineering, distributed programming, high-level languages, various design techniques, life cycles, softwarereliability and reusability, national standards and standardization efforts, artificial intelligence applications including expert systems. verification and validation methods and other software applications on telecommunication systems. Operating systems. interfaces, data processing techniques, simulation models and algorithms and interactive programming are also considered.
Open distributed computer systems.are some of the most successful structures ever designed for the computer community together with their undisputed benefits for users. However, their complexity has also introduced a ...
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ISBN:
(纸本)0769526411
Open distributed computer systems.are some of the most successful structures ever designed for the computer community together with their undisputed benefits for users. However, their complexity has also introduced a few side-effects, most notably the unpredictable nature of the underlying environments and reconfiguration burdens imposed by environmental changes. Thus, to gain high level of system performance, a required level of reliability has to be maintained. In this paper, we propose a mechanism to analyze the underlying environmental faults and failures. This model provides an adaptable fault-tolerant approache in order to address unanticipated events and unpredictable hazards in distributedsystems. Therefore, this model maintains the required reliability by analyzing the environment and selects the optimal replication strategy for existing conditions. This pragmatic and theoretically appealing approach is a part of the Juice system which supports adaptation properties for open distributed environments.
Major efforts have been spent in recent years to improve the performance, scalability and reliability of distributedsystems. In order to hide the complexity of designing distributed applications, many proposals provi...
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ISBN:
(纸本)9781538683019
Major efforts have been spent in recent years to improve the performance, scalability and reliability of distributedsystems. In order to hide the complexity of designing distributed applications, many proposals provide efficient high-level communication abstractions (e.g., atomic multicast). These abstractions, however, are often unfamiliar to average application designers and, as a result, implementing distributed applications that tolerate failures and scale performance without sacrificing consistency remains a challenging task. In this paper, we introduce DMap, a reliable and scalable distributed ordered map. DMap fully implements the generic Java SortedMap interface and can be easily used to scale existing Java applications. To substantiate our claim, we have used DMap to turn H2, a centralized database, into a scalable and reliable data management system.
An engineering technology and formalized guidelines for automated development of system architectures are vital for assuring correctness, faultlessness, security, performance and reliability of enterprise IT systems. ...
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ISBN:
(纸本)1424402158
An engineering technology and formalized guidelines for automated development of system architectures are vital for assuring correctness, faultlessness, security, performance and reliability of enterprise IT systems. The described in this article approach leads to improved automation of development of correct architectural UML deployment and component diagrams for J2EE based hardware-softwaresystems.
distributed Hash Table (DHT) P2P systems.provide flexible management of large scale distributedsystems. They also provide efficient object localization given its key. However, they don't provide high level query ...
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ISBN:
(纸本)0769521681
distributed Hash Table (DHT) P2P systems.provide flexible management of large scale distributedsystems. They also provide efficient object localization given its key. However, they don't provide high level query languages to formulate such location queries. Recent efforts have been made to improve such querying capabilities. Nevertheless, most of the proposed solutions are based on special hashing functions or on an additional level of peers. This paper presents PinS, a P2P interrogation and indexation middle-ware for DHT based P2P systems. It improves data sharing in such systems.by supporting declarative queries and some facilities on data management without using particular hash functions or other requirements. Location queries may be conjunctions or disjunctions of conditions including comparison terms, and users may specify some evaluation constraints. Comprehensive or partial answers are provided. PinS supports pre-defined and customized attributes to describe objects and allows sharing objects with restricted access. Additionally PinS enables several query execution strategies and proposes the use of indexes to improve comparison queries support. Our performance analysis shows the scalability of the system. In particular, the complexity of the evaluation of conjunctive queries is independent of the number of objects registered in the system.
Smart grids are fostering a paradigm shift in the realm of power distribution systems. Whereas traditionally different components of the power distribution system have been provided and analyzed by different teams, sm...
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ISBN:
(纸本)9781479923663
Smart grids are fostering a paradigm shift in the realm of power distribution systems. Whereas traditionally different components of the power distribution system have been provided and analyzed by different teams, smart grids require a unified and holistic approach taking into consideration the interplay of distributed generation, distribution automation topology, intelligent features, and others. In this paper, we use transient survivability metrics to create better distribution automation network designs. Our approach combines survivability analysis and power flow analysis to assess the survivability of the distribution power grid network. Additionally, we present an initial approach to automatically optimize available investment decisions with respect to survivability and investment costs. We have evaluated the feasibility of this approach by applying it to the design of a real distribution automation circuit. Our empirical results indicate that the combination of survivability analysis and power flow can provide meaningful investment. decision support for power systems.engineers.
Critical infrastructures provide services upon which society depends heavily;these applications are themselves dependent on distributed information systems.for all aspects of their operation and so survivability of th...
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Critical infrastructures provide services upon which society depends heavily;these applications are themselves dependent on distributed information systems.for all aspects of their operation and so survivability of the information systems.is an important issue. Fault tolerance is a mechanism by which survivability can be achieved in these information systems. We outline a specification-based approach to fault tolerance, called RAPTOR, that enables structuring of fault-tolerance specifications and an implementation partially synthesized front the formal specification. The RAPTOR approach uses three specifications describing the fault-tolerant system, the errors to be detected, and the actions to take to recover front those errors. System specification utilizes an object-oriented database to store the descriptions associated with these large, complex systems. The error detection and recovery specifications are defined using the formal specification notation Z. We also describe an implementation architecture and explore our solution with a case study.
The authors address the problem of state inconsistencies (i. e. , interacting processes having different and inconsistent views of one another) that arise at the kernel level of distributedsystems.based on local area...
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ISBN:
(纸本)0818606908
The authors address the problem of state inconsistencies (i. e. , interacting processes having different and inconsistent views of one another) that arise at the kernel level of distributedsystems.based on local area networks. Such systems.are particularly susceptible to state inconsistencies becaue entities are highly autonomous and thus may fail independently. The problem is compounded by the inherent delays and errors in communicating events between machines in the network. A description is given of three common classes of events that may cause state inconsistencies: (1) failures of processes, machines, and/or the network;(2) new machines joining or exiting from the system;and (3) processes or hosts migrating from one machine to another in the network. Systematic solutions to the problems, based mainly on the concept of kernel-supported process aliases, are presented. The solutions are structured and easy to understand.
A major obstacle in implementing a rollback recovery scheme for fault tolerance in a concurrent distributed system is the domino effect. A low overhead checkpointing scheme is proposed to prevent this effect. Each pro...
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A major obstacle in implementing a rollback recovery scheme for fault tolerance in a concurrent distributed system is the domino effect. A low overhead checkpointing scheme is proposed to prevent this effect. Each process saves its state periodically. The state-save synchronization among processes is implemented by bounding clock drifts. A communication protocol that assures that all saved states are consistent is developed.
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