Two design rules which aid the construction of distributed computing systems.and the provision of fault tolerance are described, namely that: (i) a distributed computing system should be functionally equivalent to the...
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ISBN:
(纸本)0818605014
Two design rules which aid the construction of distributed computing systems.and the provision of fault tolerance are described, namely that: (i) a distributed computing system should be functionally equivalent to the individual computing systems.of which it is composed, and (ii) fault tolerant systems.should be constructed from generalized fault tolerant components. The reasoning behind these two 'recursive structuring principles', and the consequences of attempting to adhere to them, are discussed. Where appropriate this discussion is illustrated by reference to a distributed system based on UNIX that is now operational at Newcastle and several other locations. This system has been implemented by adding a software subsystem, known as the Newcastle Connection, to each of a set of UNIX systems. By this means the authors has constructed a distributed system which is functionally equivalent at both the user and the program level to a conventional uniprocessor UNIX system.
The use of logs to provide recovery from failures in transaction systems.is well known. Checkpointing is also a familiar technique for speeding restart from failures. However, most work on logs and checkpointing has c...
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ISBN:
(纸本)0818605014
The use of logs to provide recovery from failures in transaction systems.is well known. Checkpointing is also a familiar technique for speeding restart from failures. However, most work on logs and checkpointing has considered only centralized systems. In this paper a logging, checkpointing, and restart mechanism is described for distributedsystems. Moreover, nested transactions are used to enhance the performance and flexibility of the design. The result is that actions occurring at different sites can be significantly decoupled while avoiding any domino effect. Further, unreliability of one site has a limited impact on performance elsewhere.
In this paper the authors present fault-tolerant softwarereliability models based on component reliabilities. Two methods for estimating component reliabilities and the associated variances are given along with an ap...
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ISBN:
(纸本)0818605014
In this paper the authors present fault-tolerant softwarereliability models based on component reliabilities. Two methods for estimating component reliabilities and the associated variances are given along with an approach for calculating the system reliability estimate variance. The derived models are used as a basis for discussing trade-offs between the two dominate fault-tolerant software strategies, Recovery Blocks and N-Version Programming.
This paper describes an object-oriented design model for structuring reliable distributedsystems. A system is viewed as a collection of objects that are accessed and modified by transactions. Recovery techniques are ...
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ISBN:
(纸本)0818605014
This paper describes an object-oriented design model for structuring reliable distributedsystems. A system is viewed as a collection of objects that are accessed and modified by transactions. Recovery techniques are incorporated to make transactions atomic in the presence of component crashes and concurrent operations. Atomicity of transactions is based on constructing recoverable objects using multiple versions and commit protocols. These concepts are extended to nested transactions. The operations on distributed objects are performed as remote procedure calls. This requires implementation of remote procedure calls in a reliable fashion. The facilities of reliable nested transactions and remote procedure calls are used to synthesize distributed objects that are highly reliable.
Independently updating copies of a database during a network partition may lead to data inconsistencies and anomalous behavior. To better cope with these problems, we propose principles for the design of the database ...
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ISBN:
(纸本)0818605014
Independently updating copies of a database during a network partition may lead to data inconsistencies and anomalous behavior. To better cope with these problems, we propose principles for the design of the database schema and transactions. The authors also propose a tool (Data-patch) that aids the database administrator in the development of an integration program for database copies that diverged.
Many proposals have been made for structuring distributed programs. This paper looks at one such proposal, the one embedded in the Argus programming language and system. The paper provides a discussion of decisions ma...
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ISBN:
(纸本)0818605014
Many proposals have been made for structuring distributed programs. This paper looks at one such proposal, the one embedded in the Argus programming language and system. The paper provides a discussion of decisions made in the two major areas of process structure and communication, and compares the chosen structures with alternatives. The paper emphasizes the rationale for decisions and the issues that must be considered in making such decisions.
This paper describes the requirements and attributes of the Experimental distributed Processing Facility (EDPF). The EDPF will provide a flexible and dynamically reconfigurable distributed environment that will be use...
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ISBN:
(纸本)0818605014
This paper describes the requirements and attributes of the Experimental distributed Processing Facility (EDPF). The EDPF will provide a flexible and dynamically reconfigurable distributed environment that will be used to address generic distributed processing issues as applied to the needs of the future battlefield. Survivability and reliability are the key issues under investigation. The EDPF will integrate the requirements for standard hardware and software. This facility will focus on loosely coupled nodes over newly developed (e. g. , fiber optics) or transitional communications media. All designs and implementations performed on the EDPF will use the Ada programming language. The EDPF will be used in a laboratory environment where system performance analysis can be performed on various distributed processing models. The EDPF will be capable of being deployed in a field environment for future tactical demonstrations.
作者：
Banatre, J.P.Banatre, M.Ployette, F.INSA
Inst de Recherche en Informatique et Systemes Aleatoires Rennes Fr INSA Inst de Recherche en Informatique et Systemes Aleatoires Rennes Fr
The first part of this paper describes a distributed auction bidding system and its major requirements. The hardware and software structure of the system are quickly sketched. The second part of the paper concentrates...
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ISBN:
(纸本)0818605014
The first part of this paper describes a distributed auction bidding system and its major requirements. The hardware and software structure of the system are quickly sketched. The second part of the paper concentrates upon crash recovery aspects in the system. The three major aspects which are developed concern: (i) stable storage, (ii) implementation of commit protocol and (iii) description of recovery algorithms.
作者：
York, GaryCarnegie-Mellon Univ
Dep of Electrical Engineering Pittsburgh PA USA Carnegie-Mellon Univ Dep of Electrical Engineering Pittsburgh PA USA
Many modern reliable systems.are N-modular redundancy and voting to achieve the required reliability. Most of these systems.assume that the redundant modules are synchronized. Experiments have been performed on the mu...
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ISBN:
(纸本)0818605014
Many modern reliable systems.are N-modular redundancy and voting to achieve the required reliability. Most of these systems.assume that the redundant modules are synchronized. Experiments have been performed on the multiprocessor with redundant software modules that are allowed to execute with various degrees of asynchrony. The performance of such systems.has been experimentally determined along two lines. The first experiment determined how much overhead is added to the system execution time as the voting frequency changes. The second experiment shows how much asynchrony can be tolerated in prcess execution for three different experimental paradigms. Mathematical models for the experiments have been developed that closely model the experimental results.
作者：
Thanos, C.Carlesi, C.Bertino, E.CNR
Istituto di Elaborazione della Informazione Pisa Italy CNR Istituto di Elaborazione della Informazione Pisa Italy
In this paper the relationship between average transaction response time and the static degree of interference for four concurrency control algorithms based on two-phase locking is established. In particular the incre...
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ISBN:
(纸本)0818605014
In this paper the relationship between average transaction response time and the static degree of interference for four concurrency control algorithms based on two-phase locking is established. In particular the increase in average response time has been measured with respect to the static degree of interference for a given multiprogramming level, database and transaction size. Also the increase in average probability of a lock request conflicting with another one has been measured with respect to the static degree of interference. In addition the average number of aborted transactions has been measureed for each algorithms.
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