Download or read book A Consistency Model for Distributed Shared Memory on RHODOS Among Shared Memory Consistency Models written by J. Silcock and published by . This book was released on 1996 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distributed Shared Memory Consistency Models written by Venkateswarlu Chennareddy and published by Independently Published. This book was released on 2024-02-07 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book talks about the Specification and Verification of Distributed Shared Memory Relaxed Consistency Models specifically Weak Consistency Models. For this, an abstract Distributed Shared Memory (DSM) has been designed and implemented using CADP (Construction and Analysis of Distributed Processes). In DSM, sequential consistency unnecessarily reduces the performance of the system because it does not allow reordering or pipelining the memory operations. Weak consistency allows the reordering of memory events and buffering or pipelining of memory accesses so weak consistency improves the performance of the DSM system. For any critical system, it is very important to develop methods that increase our confidence in the correctness of such systems. One such method for the correctness of critical systems is formal verification. For verification of the weak consistency model, the properties of weak consistency have been specified and verified on the Abstract DSM System using CADP Toolbox.
Download or read book Shared Memory Consistency Models written by Abdul Naeem and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: The shared memory systems should support parallelization at the computation (multiprocessor), communication (Network-on-Chip, NoC) and memory architecture levels to exploit the potential performance benefits. Such systems are facing the critical issues of memory consistency and coherence. Memory consistency issue arises due to the unconstrained operations which sometimes lead to the unexpected behavior of the systems. Memory consistency models are used to resolve this issue. Relaxed or weaker consistency models enforce less ordering constraints on the memory operations and exploit system optimizations compared to the stricter models. This book discusses the novel realization schemes and scalability analysis of strict Sequential Consistency (SC) model and relaxed memory consistency models: Total Store Ordering (TSO), Partial Store Ordering (PSO), Weak Ordering (WO), Release Consistency (RC), and Protected Release Consistency (PRC) in the NoC based distributed shared memory multiprocessor systems. This study should help the average readers and professionals to understand the critical issue of memory consistency both in the NoC based systems and general purpose multiprocessor systems.
Download or read book Consistent Distributed Storage written by Vincent Gramoli and published by Springer Nature. This book was released on 2022-05-31 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a shared memory abstraction in distributed systems is a powerful tool that can simplify the design and implementation of software systems for networked platforms. This enables the system designers to work with abstract readable and writable objects without the need to deal with the complexity and dynamism of the underlying platform. The key property of shared memory implementations is the consistency guarantee that it provides under concurrent access to the shared objects. The most intuitive memory consistency model is atomicity because of its equivalence with a memory system where accesses occur serially, one at a time. Emulations of shared atomic memory in distributed systems is an active area of research and development. The problem proves to be challenging, and especially so in distributed message passing settings with unreliable components, as is often the case in networked systems. We present several approaches to implementing shared memory services with the help of replication on top of message-passing distributed platforms subject to a variety of perturbations in the computing medium.
Download or read book Views and Consistencies in Distributed Shared Memory written by Gabriel Girard and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The distributed shared memory (DSM) abstraction is a very popular programming paradigm in parallel and distributed environments. However, DSM often suffers from performance problems as consistency requirements often incur long access latencies that cannot be overlapped with other operations in a process. Sequential consistency is the most general consistency requirement for DSM systems. This thesis explores two different avenues to solve the performance problem for DSM systems. First, for sequentially consistent DSM, we introduce a new strategy to minimize synchronization cost and maximize the hiding of synchronization delays in a process. The strategy is based on the knowledge of spatial locality in the sharing of memory objects. An access graph is used to capture the sharing relationship among processes via the shared objects. We show that if accesses in all cycles are 'properly' synchronized, then the execution is guaranteed to be sequentially consistent. We develop two distinct solution strategies to ensure proper synchronization. (i) Neighbor protocol: conflicting accesses between two neighbors in an access cycle must be synchronized, and (ii) flush protocol: asynchronous accesses in an access cycle must be eventually synchronized by a special flush-access in the cycle. Simulation experiments have shown significant improvements in performance in our protocols, especially in the case of the flush protocol. Another strategy to improve performance of DSM systems is to adopt a weaker consistency model so that blocking among some memory operations can be removed. In this thesis, we use the primitive notion of program-order and value-order to define global view. Using this as a seed, various consistency models evolve and form multiple hierarchies of models. The creation of these models and hierarchies comes via one of the following means: (i) a global view is augmented with additional ordering among its operations whenever some orderings exist, or (ii) besides linearizability of a global view, certain orderings must not co-exist in it. The former involves augmentation rules, and the latter involves causality requirements. The creation of these hierarchies leads to several novel consequences: the notion of exact implementation is introduced, new protocols are discovered and the precise analysis of access behaviors of an application is now possible.
Download or read book Distributed Shared Memory and Data Consistency written by Krzysztof Piotrowski and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2012-03 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work investigates the feasibility of data consistency models to be used in Distributed Shared Memory (DSM) for Wireless Sensor Networks (WSN) to enable more powerful distributed systems with reliable data exchange. It starts with an introduction of WSN and consistency related approaches. Based on these basics, mechanisms that enable data consistency are discussed as a theoretical framework for the prototypical implementation of a data consistency providing middleware that was implemented as part of this work. The proposed middleware adapts the mechanisms known from the original memory consistency approaches to make them usable in the sensor network area and also proposes own low cost mechanisms. The latter are at least partially based on the idea that within the shared memory in WSNs the information is the major concern and by that the replica update rates can be tailored to the application. In order to allow for ease of use of the middleware, the replication schemes and the consistency mechanisms are defined by the application engineer as a policy. The most appropriate memory consistency models were implemented and evaluated using the framework proposed in this work.
Download or read book Modeling Sequential Consistency in a Distributed Shared Memory System written by Christoph Lindemann and published by . This book was released on 1991 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The compact DSPN is employed for a quantitative performance analysis of the sequential consistency protocol. A detailed evaluation of the sequential consistency protocol is presented which give [sic] important hints for designing more relaxed consistency models."
Download or read book Comparative Study of Various Consistency Models in Distributed Shared Memory System written by Sindhu Singh and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distributed Shared Memory (DSM) is a collection of nodes or clusters, each with its own memory connected by an interconnected network. The key issue in DSM is keeping the memory pages consistent. It refers to the degree of consistency that has to be maintained for the shared memory data. Maintaining perfect consistency is especially painful when the difference between the latency and/or throughput of memory accesses on the one hand, and the network connecting the machines on which these copies reside on the other, is big. The solution might be to accept less than perfect consistency as the price for better performance. This paper reviews various memory consistency models which are used in different DSM systems.
Download or read book Consistency Model Transitions in Shared Memory written by Robert Christian Steinke and published by . This book was released on 2001 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distributed Shared Memory written by Jelica Protic and published by John Wiley & Sons. This book was released on 1997-08-10 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers present in this text survey both distributed shared memory (DSM) efforts and commercial DSM systems. The book discusses relevant issues that make the concept of DSM one of the most attractive approaches for building large-scale, high-performance multiprocessor systems. The authors provide a general introduction to the DSM field as well as a broad survey of the basic DSM concepts, mechanisms, design issues, and systems. The book concentrates on basic DSM algorithms, their enhancements, and their performance evaluation. In addition, it details implementations that employ DSM solutions at the software and the hardware level. This guide is a research and development reference that provides state-of-the art information that will be useful to architects, designers, and programmers of DSM systems.
Download or read book The Design and Implementation of Distributed Shared Memory Based on Scope Consistency written by Wenlian Yang and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distributed Shared Memory (DSM) is one of the main approaches to implement distributed computing. The purpose of this project is to design and implement a prototype DSM that runs on popular TCP/IP networked Window PCs without special compliers and/or linkers. Our DSM uses lock based scope consistency (ScC), and supports central model, multiple server model and fully distributed model. We use object-oriented method to encapsulate these models within one framework. We provide C++ APIs and a DSM engine for C++ programmers to use DSM functions. The project is developed using C++ and Winsock APIs under Windows NT platform.
Download or read book Relaxing Consistency in Recoverable Distributed Shared Memory written by and published by . This book was released on 1993 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Relaxed memory consistency models tolerate increased memory access latency in both hardware and software distributed shared memory systems. In recoverable systems, relaxing consistency has the added benefit of reducing the number of checkpoints needed to avoid rollback propagation. In this paper, we introduce new checkpointing algorithms that take advantage of relaxed consistency to reduce the performance overhead of checkpointing. We also introduce a scheme based on lazy relaxed consistency, that reduces both checkpointing overhead and the overhead of avoiding error propagation in systems with error latency. We use multiprocessor address traces to evaluate the relaxed consistency approach to checkpointing with distributed shared memory.
Download or read book Designing Memory Consistency Models for Shared memory Multiprocessors written by Sarita Vikram Adve and published by . This book was released on 1993 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Algorithms And Architectures For Parallel Processing Proceedings Of The 1997 3rd International Conference written by Andrzej Marian Goscinski and published by World Scientific. This book was released on 1997-11-15 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt: The IEEE Third International Conference on Algorithms and Architectures for Parallel Processing (ICA3PP-97) will be held in Melbourne, Australia from December 8th to 12th, 1997. The purpose of this important conference is to bring together developers and researchers from universities, industry and government to advance science and technology in distributed and parallel systems and processing.
Download or read book Recoverable Distributed Shared Memory Under Sequential and Relaxed Consistency written by and published by . This book was released on 1995 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distributed shared memory (DSM) implemented on a cluster of workstations is an increasingly attractive platform for executing parallel scientific applications. Checkpointing and rollback techniques can be used in such a system to allow the computation to progress in spite of the temporary failure of one or more processing nodes. The complexity and overhead inherent in traditional message-passing checkpointing techniques can be reduced by taking advantages of specific properties of DSM. In this paper we show that, if designed correctly, a DSM system only needs to consider a subset of message-passing dependencies for correct rollback. A passive server model of DSM computation is described that allows a loosening of dependency restrictions by considering the events involved in interactions between nodes as atomic. An ownership timestamp scheme is used to eliminate many of the dependencies related to keeping directories consistent. The schemes can be implemented in DSM hardware by simply redesigning the directory at the network interface. Finally, we show that by relaxing the memory consistency model and using lazy release consistency, it is possible to further relax dependency restrictions. (AN).
Download or read book Virtual Shared Memory for Distributed Architectures written by Eva Kühn and published by Nova Publishers. This book was released on 2001 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Virtual Shared Memory for Distributed Architecture
Download or read book Memory Consistency Models for Shared Memory Multiprocessors written by Kourosh Gharachorloo and published by . This book was released on 1995 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: We believe that the combined benefits in hardware and software will make relaxed models universal in future multiprocessors, as is already evidenced by their adoption in several commercial systems.
