The symposium Materials contain 21 papers. The following topics are dealt with: checkpointing and logging algorithms;backward recovery schemes;replication and parallelism;dependability modeling and assessment;agreemen...
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ISBN:
(纸本)0818622601
The symposium Materials contain 21 papers. The following topics are dealt with: checkpointing and logging algorithms;backward recovery schemes;replication and parallelism;dependability modeling and assessment;agreement;and garbage collection.
The authors present a novel formal approach to proving the correctness of distributedsystems.of replicated processes that commuicate by message passing. The notion of correctness introduced is based on the consistenc...
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ISBN:
(纸本)0818622601
The authors present a novel formal approach to proving the correctness of distributedsystems.of replicated processes that commuicate by message passing. The notion of correctness introduced is based on the consistency of the replicated system with its nonreplicated counterpart. The formal framework of CSP (communicating sequential processes) allows the proof of partial correctness and deadlock-freedom properties of the systems.of replicated processes. The authors also discuss how a replicated process may be implemented by N-base copies, a majority of which are non-faulty, and point out the necessity of coordinating the copies and the requirements they should satsify.
This paper presents a feasibility study of two combined techniques for software fault tolerance in distributedsystems. A probabilistic model for each technique is presented that represents each technique's abilit...
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Although many solutions to the problem of representing spatial data have been proposed, most are not practical. They cannot be guaranteed to perform well with large and arbitrarily distributed data collections. They m...
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For efficient construction of the distributeddatabase from media failure, a transaction-consistent checkpointing algorithm is proposed for heterogeneous distributeddatabasesystems. For full design autonomy and incr...
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For efficient construction of the distributeddatabase from media failure, a transaction-consistent checkpointing algorithm is proposed for heterogeneous distributeddatabasesystems. For full design autonomy and increased availability on the heterogeneous distributeddatabasesystems. the proposed algorithm never enforces termination of normal operations of transactions and changes of checkpointing algorithms in local databasesystems. The global checkpoints generated by the algorithm can be used to reconstruct the previous consistent states of a database efficiently.< >
The author introduces queueing network models for the optimization of the concurrent evaluation of complex database queries, which occur e.g. in deductive query processing. The basic principle for the optimization is ...
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The author introduces queueing network models for the optimization of the concurrent evaluation of complex database queries, which occur e.g. in deductive query processing. The basic principle for the optimization is the reduction of response time by a better load distribution. If data access leads to a bottleneck on any CPU, response time may possibly be reduced by a preceding dynamic replication of one or more tables, whose accesses make up the bottleneck, to a disc managed by a lighter loaded CPU. For the comparison of alternative concurrent execution plans only queueing network models give quantitative results, which consider the contention on resources like CPU or disc.< >
Presents a feasibility study of two combined techniques for software fault tolerance in distributedsystems. A probabilistic model for each technique is presented that represents a technique's ability to recover f...
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Presents a feasibility study of two combined techniques for software fault tolerance in distributedsystems. A probabilistic model for each technique is presented that represents a technique's ability to recover from software and hardware faults that occur with arbitrary frequency. The goal is not to accurately predict the behavior of systems.that employ these techniques, but rather to identify the strong and weak points of each approach under varying circumstances of dependability in both the system and the fault-tolerance components. An example study shows how these models can be used to understand the influence of component failures on the reliability of systems.using these two approaches.< >
Although many solutions to the problem of representing spatial data have been proposed, most are not practical. They cannot be guaranteed to perform well with large and arbitrarily distributed data collections. They m...
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Although many solutions to the problem of representing spatial data have been proposed, most are not practical. They cannot be guaranteed to perform well with large and arbitrarily distributed data collections. They may not be easily integrated with concurrency and recovery software already written for databasesystems. However, two proposed structures do have some guarantees, similar to those which have made the B/sup +/-tree so successful for one-dimensional data. These analytic guarantees include worst case space utilization in data and index pages, a minimal fan-out and exact match search time bounded by the height of the tree. The two methods are the holey brick tree and bit interleaving using a B/sup +/-tree. Both can also be integrated with concurrency and recovery systems.in the same way that B/sup +/-trees are.< >
The proposed coordinator log transaction execution protocol centralizes logging on a per-transaction basis and exploits piggybacking to provide the semantics of a distributed atomic commit without the associated costs...
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The proposed coordinator log transaction execution protocol centralizes logging on a per-transaction basis and exploits piggybacking to provide the semantics of a distributed atomic commit without the associated costs. This protocol eliminates two rounds of messages (one phase) from the presumed commit protocol and dramatically reduces the number of log forces needed for distributed atomic commit. The authors compare the coordinator log transaction execution protocol with existing protocols, describe when it is desirable, and discuss how it affects the write-ahead log protocol and the database crash recovery algorithm.
distributed synchronization for data sharing is discussed, and the design of a distributed lock manager for the Camelot transaction facility is presented. The lock manager is a component of a proposed implementation o...
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distributed synchronization for data sharing is discussed, and the design of a distributed lock manager for the Camelot transaction facility is presented. The lock manager is a component of a proposed implementation of data sharing in the Camelot environment. A number of experiments that demonstrate the correct operation of the lock manager are reported and its performance is described. The performance metrics indicate that distributed lock management should not reduce the feasibility of data sharing in this environment. The similarity between the caching and synchronization strategies appropriate for locks and data suggests that protocols developed for distributed locks will be applicable to data sharing.
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