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Fault recovery based on parallel recomputing in transactional memory system

Lecture Notes in Electrical Engineering 2011年 98卷 995-1002页

作者： Song, Wei Jia, Jia National Laboratory for Parallel and Distributed Processing School of Computer National University of Defense Technology Changsha410073 China

ISBN: (纸本)9783642217647

This paper addresses the issue of fault recovery in transactional memory, and proposes a method of fault recovery based on parallel recomputing in transactional memory system. This method utilizes the dataversioning mechanism of transactional memory system to avoid the extra cost of state saving, rolls back a single transaction to avoid wasting the computing time of the fault-free transactions, and adopts the parallel recomputing method to reduce the cost of fault recovery. This paper applies this method to OpenTM programs, and proposes the implementation method of parallel recomputing in OpenTM. At last, this paper tests the performance of this method through a test program. The experimental results show that, compared with the fault recovery method of rolling back a single transaction, the parallel recomputing method in transactional memory system can execute the fault recovery quickly and accurately and the method has a well scalability. © Springer-Verlag Berlin Heidelberg 2011.

关键词： Fault tolerance

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A Hierarchical Memory Service Mechanism in Server Consolidation Environment

A Hierarchical Memory Service Mechanism in Server Consolidat...

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International Conference on parallel and distributed Systems (ICPADS)

作者： Liufeng Wang Huaimin Wang Lu Cai Rui Chu Pengfei Zhang Lanzheng Liu National Key Laboratory for Parallel and Distributed Processing National University of Defense Technology Changsha China School of Economics and Management Xi'an University Xi'an China

Increasing Internet business and computing footprint motivate server consolidation in data centers. Through virtualization technology, server consolidation can reduce physical hosts and provide scalable services. However, the ineffective memory usage among multiple virtual machines (VMs) becomes the bottleneck in server consolidation environment. Because of inaccurate memory usage estimate and the lack of memory resource managements, there is much service performance degradation in data centers, even though they have occupied a large amount of memory. In order to improve this scenario, we first introduce VM's memory division view and VM's free memory division view. Based on them, we propose a hierarchal memory service mechanism. We have designed and implemented the corresponding memory scheduling algorithm to enhance memory efficiency and achieve service level agreement. The benchmark test results show that our implementation can save 30% physical memory with 1% to 5% performance degradation. Based on Xen virtualization platform and balloon driver technology, our works actually bring dramatic benefits to commercial cloud computing center which is providing more than 2,000 VMs' services to cloud computing users.

关键词： Memory management Resource management Servers Scheduling algorithm Benchmark testing Cloud computing System performance

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Context-Aware Scheduling in Wireless Networks with Successive Interference Cancellation

Context-Aware Scheduling in Wireless Networks with Successiv...

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IEEE International Conference on Communications Workshops

作者： Shaohe Lv Weihua Zhuang Xiaodong Wang Xingming Zhou National Laboratory of Parallel and Distributed Processing National University of Defense Technology Department of Electrical and Computer Engineering University of Waterloo

ISBN: (纸本)9781612842325

We consider the greedy scheduling based on the physical model in wireless networks with successive interference cancellation (SIC). There are two major stages in a scheduling scheme, link selection (to decide which link is scheduled next) and time slot selection (to deciding which slot is allocated to a given link). Most available schemes take a first-fit policy in the latter and strive to achieve good performance by careful selection of link ordering with respect to interference. Due to the accumulation effect and sequential detection nature of SIC, however, it is difficult to evaluate the interference of a link. As a result, many existing scheduling schemes become less efficient. In this paper, we take a new look on the problem and focus to the time slot selection stage. We define tolerance margin to measure the saturation of a link set and present two heuristic policies: one is to schedule a link to a slot such that the resulting set of links has a maximum tolerance margin;the other is to choose a slot such that the increase of tolerance margin is minimum. Simulation results show that the performance of the proposed schemes is better than the first-fit policy and is close to the optimal solution.

关键词： Link scheduling Successive interference cancellation Physical interference model

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An Economical Power Management for High Performance Computers

An Economical Power Management for High Performance Computer...

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International Conference on Computational and Information Sciences (ICCIS)

作者： Huiquan Wang Xinhai Xu Jing Zhou Hao Zhou Guibin Wang National Laboratory for Parallel and Distributed Processing National University of Defense Technology Changsha Hunan P. R. China

The large amount of energy consumption of high performance computers represent significant financial cost. If we consider the specific situation of electricity price, a measure which makes the energy consumption the lowest is usually not the best on economy. This paper proposes an economical approach for designing a power management plan that reduces the assessment of energy consumption of high performance computers. By taking account of the electricity price in different periods during the day, we assign the workload to each period properly to make the electricity fee as low as possible. A simulation of the cases of a single task and multi-task demonstrates how our approach can be used. The results of the simulation show that our approach can save the electricity fee produced by high performance computers effectively. In the single task case, the proposed approach saves the electricity fee of 10.08% on average, and in the multi-task case the proportion of saved fee is 12.67%.

关键词： Electricity Supercomputers Energy consumption Mathematical model Power demand Equations

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An ordering-based approach to the evaluation of trust systems

An ordering-based approach to the evaluation of trust system...

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International Conference on Communication Software and Networks, ICCSN

作者： Wei Liu Yang-Bin Tang Huai-Min Wang Gang Lu School of Computer National University of Defense Technology Changsha Hunan China National Laboratory for Parallel and Distributed Processing Changsha Hunan China

Trust systems provide a promising way to build trust relationships among users in distributed and opening systems. However, it is difficult to make quantitatively comparative analysis on different trust systems because of the different application settings and the lack of effective measures. This paper constructs a framework of trust systems in terms of linear algebra, which helps us model and implement different systems in a uniform way. Besides, we propose an ordering-based approach to evaluating trust systems, then give two relevant ordering-base measures. The experiment results suggests that our method provides an effective way to analyze and evaluate trust systems.

关键词： Computational modeling Blogs

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A Unified Co-Processor Architecture for Matrix Decomposition

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Journal of Computer Science & Technology 2010年第4期25卷 874-885页

作者：窦勇周杰邬贵明姜晶菲雷元武倪时策 National Laboratory for Parallel & Distributed Processing National University of Defense Technology National Laboratory for Parallel & Distributed Processing.National University of Defense Technology

QR and LU decompositions are the most important matrix decomposition algorithms. Many studies work on accelerating these algorithms by FPGA or ASIC in a case by case style. In this paper, we propose a unified framework for the matrix decomposition algorithms, combining three QR decomposition algorithms and LU algorithm with pivoting into a unified linear array structure. The QR and LU decomposition algorithms exhibit the same two-level loop structure and the same data dependency. Utilizing the similarities in loop structure and data dependency of matrix decomposition, we unify a fine-grained algorithm for all four matrix decomposition algorithms. Furthermore, we present a unified co-processor structure with a scalable linear array of processing elements （PEs）, in which four types of PEs are same in the structure of memory channels and PE connections, but the only difference exists in the internal structure of data path. Our unified co-processor, which is IEEE 32-bit floating-point precision, is implemented and mapped onto a Xilinx Virtex5 FPGA chip. Experimental results show that our co-processors can achieve speedup of 2.3 to 14.9 factors compared to a Pentium Dual CPU with double SSE threads.

关键词： co-processor matrix decomposition fine-grained parallel FPGA

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The prediction model based on RBF network in achieving elastic cloud

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Advances in Information Sciences and Service Sciences 2011年第11期3卷 67-78页

作者： Shi, Peichang Wang, Huaimin Ding, Bo Liu, Ran Wang, Tianzuo National Laboratory for Parallel and Distributed Processing School of Computer and Science National University of Defense Technology China Department of Electronics and Information Engineering Huazhong University of Science Technology China

Cloud needs to have rapid and elastic resources supply capability, because of the fluctuant resources demand of end-users. Multi-scale resources elastic binding is an important method to provide cloud services with rapid and elastic service capability. The most challenging problem in multi-scale resources elastic binding is how to predict the dynamic resource demand of end-users, and then decide when and to what extent multi-scale resources need elastic binding based on the prediction. In this paper, we present the prediction model based on RBF (Radial Basis Function) Network, which is used to predict end-users resource demand in advance. Compared with current prediction methods, it has faster prediction speed and higher prediction accuracy. Then we use traces data (the bandwidth demand of Web type of cloud services) collected from a real-world cloud provider: ChinaCache, as the training and testing data set to validate the method. Finally, we evaluate the predicted results using general prediction accuracy metrics. The results prove that the prediction model based on RBF network is able to resolve the decision problem in multi-scale resources elastic binding.

关键词： Radial basis function networks

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An energy-efficient scheduling algorithm for sporadic real-time tasks in multiprocessor systems

An energy-efficient scheduling algorithm for sporadic real-t...

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13th IEEE International Workshop on FTDCS 2011, the 8th International Conference on ATC 2011, the 8th International Conference on UIC 2011 and the 13th IEEE International Conference on HPCC 2011

作者： Zhang, Dong-Song Chen, Fang-Yuan Li, Hong-Hua Jin, Shi-Yao Guo, De-Ke National Laboratory for Parallel and Distributed Processing School of Computer National University of Defense Technology Changsha 410073 China School of Computing Science Simon Fraser University 8888 University Drive Burnaby BC V5A 1S6 Canada National Laboratory for Information System Engineering School of Information Systems and Management National University of Defense Technology Changsha 410073 China

ISBN: (纸本)9780769545387

As the energy consumption of embedded multiprocessor systems becomes increasingly prominent, the real-time energy-efficient scheduling in multiprocessor systems becomes an urgent problem to reduce the system energy consumption while meeting real-time constraints. For a multiprocessor with independent DVFS and DPM at each processor, this paper proposes an energy-efficient real-time scheduling algorithm named LRE-DVFS-EACH, based on LRE-TL which is an optimal real-time scheduling algorithm for sporadic tasks. LRE-DVFS-EACH utilizes the concept of TL plane and the idea of fluid scheduling to dynamically scale the voltage and frequency of processors at the initial time of each TL plane as well as the release time of a sporadic task in each TL plane. Consequently, LRE-DVFS-EACH can obtain a reasonable tradeoff between the real-time constraints and the energy saving. LRE-DVFS-EACH is also adaptive to the change of workload caused by the dynamic release of sporadic tasks, which can obtain more energy savings. The experimental results show that compared with existing algorithms, LRE-DVFS-EACH can not only guarantee the optimal feasibility of sporadic tasks, but also achieve more energy savings in all cases, especially in the case of high workloads. © 2011 IEEE.

关键词： Real time systems

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Semantic web service composition using answer set planning

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International Journal of Advancements in Computing Technology 2011年第5期3卷 20-31页

作者： Qian, Jun-Yan Huang, Guo-Wang Zhao, Ling-Zhong National Laboratory for Parallel and Distributed Processing National University of Defense Technology Changsha 410073 China Department of Computer science and engineering Guilin University of Electronic Technology Guilin 541004 China

This paper presents a method that adapting planning description to bring the semantic information into play for service composition through action language C. It shows how service descriptions can be expressed by preconditions and effects and the action language C provides a richer syntax and semantic for complex service descriptions. We also presents the algorithm of Translating semantic Web service described by OWL-S to action language C. Thanks to the structured description and the powerful expression of C, we only consider the initial Situation and the desired goal ignoring details of transition and planning. At last we use satisfiability planning to solve the planning problem by translating the action language into disjunctive logic program.

关键词： Web services

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Performance problems online detection in cloud computing systems via analyzing request execution paths

Performance problems online detection in cloud computing sys...

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International Conference on Dependable Systems and Networks Workshops (DSN-W)

作者： Haibo Mi Huaimin Wang Gang Yin Hua Cai Qi Zhou Tingtao Sun National Laboratory for Parallel and Distributed Processing National University of Defense Technology Changsha China Computing Platform Alibaba Cloud Computing Company Hangzhou China

It is quite a headache for developers to online detect performance problems in large-scale cloud computing systems. The behavior and the hidden connections among the huge amount of runtime request execution paths in cloud computing systems usually contain useful information for performance problem detection. In this paper, we propose an approach to rapidly diagnose the source of performance degradation in large-scale non-stop cloud computing systems. The approach first groups the user requests into categories with a fast clustering algorithm; then applies the principal components analysis to extract the primary methods; finally compares the normal and abnormal behaviors of the primary methods to localize the main cause of performance problems. We conduct extensive experiments over a real-world enterprise system providing services for the public. The results show that our approach can locate the prime causes of performance problems accurately and efficiently.

关键词： Cloud computing Principal component analysis Instruments Degradation Servers Data mining Accuracy

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