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On the Effects of Transaction data access patterns on Performance in Lock-Based Concurrency Control

IEEE TRANSACTIONS ON COMPUTERS 2023年第6期72卷 1718-1732页

作者： Sanzo, Pierangelo Di Quaglia, Francesco Univ Roma Tre Dept Econ I-00154 Rome Italy Univ Roma Tor Vergata Dept Civil & Informat Engn I-00133 Rome Italy

Transaction Processing (TP) plays a primary role in the design and implementation of IT applications and services. Many TP systems exploit lock-based concurrency control to guarantee atomicity and isolation of transactions that access shared data. In this article, we show that transaction data access patterns, in particular the order of data accesses along the transaction execution, have a noticeable impact on how lock-based concurrency control affects performance. We show that the performance can remarkably change depending on whether transactions, or a percentage of them, access data items following some common ordering rule or not. We investigate on this aspect and its root causes through an analytical modeling approach, and with the evidence of data gathered through both simulation and the execution of real transactional workloads. Finally, we show how the findings of our study can be easily exploited for improving the performance of common transactional workloads.

关键词： data models Distributed databases Analytical models Concurrency control Protocols System recovery Process control Transaction processing concurrency control data access patterns performance

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PFRF: An adaptive data replication algorithm based on star-topology data grids

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FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE 2012年第7期28卷 1045-1057页

作者： Lee, Ming-Chang Leu, Fang-Yie Chen, Ying-ping Natl Chiao Tung Univ Dept Comp Sci Taipei Taiwan Tunghai Univ Dept Comp Sci Taichung Taiwan

Recently, data replication algorithms have been widely employed in data grids to replicate frequently accessed data to appropriate sites. The purposes are shortening file transmission distance and delivering files from nearby sites to local sites so as to improve data access performance and reduce bandwidth consumption. Some of the algorithms were designed based on unlimited storage. However, they might not be practical in real-world data grids since currently no system has infinite storage. Others were implemented on limited storage environments, but none of them considers data access patterns which reflect the changes of users' interests, and these are important parameters affecting file retrieval efficiency and bandwidth consumption. In this paper, we propose an adaptive data replication algorithm, called the Popular File Replicate First algorithm (PFRF for short), which is developed on a star-topology data grid with limited storage space based on aggregated information on previous file accesses. The PFRF periodically calculates file access popularity to track the variation of users' access behaviors, and then replicates popular files to appropriate sites to adapt to the variation. We employ several types of file access behaviors, including Zipf-like, geometric, and uniform distributions, to evaluate PFRF. The simulation results show that PFRF can effectively improve average job turnaround time, bandwidth consumption for data delivery, and data availability as compared with those of the tested algorithms. (C) 2011 Elsevier B.V. All rights reserved.

关键词： data grid data replication data access patterns File popularity PFRF

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SIMDified data Processing - Foundations, Abstraction, and Advanced Techniques 24

SIMDified Data Processing - Foundations, Abstraction, and Ad...

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ACM International Conference on Management of data (SIGMOD)

作者： Habich, Dirk Pietrzyk, Johannes Tech Univ Dresden Dresden Germany

ISBN: (纸本)9798400704222

Query execution techniques in database systems are constantly adapting to novel hardware features in order to improve query performance, in particular for analytical queries. In the last decade, the Single Instruction Multiple data (SIMD) paradigm was established as a state-of-the-art approach to increase the single-query performance by parallelizing in-core. Such SIMD capabilities are constantly increasing in modern processors by more comprehensive SIMD instruction set extensions. Therefore, this tutorial will provide an up-to-date overview about SIMDified query processing concepts. Conceptually, this tutorial is divided into three parts. In the first part, we lay the foundations by describing what SIMD is, what it was introduced for, and how it is traditionally used to accelerate query processing. The subsequent two parts focus on novel developments in this area. While the second part of this tutorial is dedicated to an abstraction layer to handle the increasing heterogeneity in the SIMD hardware landscape, the third part provides a survey of advanced techniques to address upcoming challenges such as wider and flexibly-sized SIMD registers.

关键词： SIMD Query processing Abstraction FPGA data access patterns

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Analysis of scratch-pad and data-cache performance using statistical methods 06

Analysis of scratch-pad and data-cache performance using sta...

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11th Asia and South Pacific Design Automation Conference

作者： Absar, Javed Catthoor, Francky Katholieke Univ Leuven IMEC VZW Louvain Belgium STMicroelect Asia Pacific Singapore Singapore

ISBN: (纸本)0780394518

An effectively designed and efficiently used memory hierarchy, composed of scratch-pads or cache, is seen today as the key to obtaining energy and performance gains in data-dominated embedded applications. However, an unsolved problem is - how to make the right choice between the scratchpad and the data-cache for different class of applications? Recent studies show that applications with regular and manifest data access patterns (e.g. matrix multiplication) perform better on the scratch-pad compared to the cache. In the case of dynamic applications with irregular and non-manifest access patterns, it is however commonly and intuitively believed that the cache would perform better. In this paper, we show by theoretical analysis and empirical results that this intuition can sometimes be misleading. When access-probabilities remain fixed, we prove that the scratch-pad, with an optimal mapping, will always outperform the cache. We also demonstrate how to map dynamic applications efficiently to scratch-pad or cache and additionally, how to accurately predict the performance.

关键词： cache storage statistical analysis access probabilities data access patterns data-cache performance scratch-pad performance statistical methods Statistical methods Notepads cache storage data analysis Statistical analysis memory hierarchy

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Visualizing I/O predictability 1

Visualizing I/O predictability

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1st International Symposium on 3D data Processing Visualization and Transmission

作者： Luo, A Amer, A Speidel, S Long, DDE Pang, A Univ Calif Santa Cruz Jack Baskin Sch Engn Santa Cruz CA 95064 USA

ISBN: (纸本)0769515215;0769515223

We propose a novel method to study storage system predictability based on the visualization of file successor entropy, a form of conditional entropy drawn from a file access trace. First-order conditional entropy can be used as a measure of predictability. It is superior to the more common measures such as independent likelihood of data access. For file access data, we developed a visualization tool that produces 3D graphical views of the variation in predictability of successive access events on a per-file basis. Our visualization tool provides interactive observation of the variations in predictability according to some arbitrary criterion, e.g. time of day, program identifier, user groups, or an), other classification of files. Four entropy data sets were extracted from various file system traces. These four data sets are representative of the variability in file access patterns for different machine use: server personal workstation, large number of interactive users, and heavy write activity. Visualization results show that there is strong predictability among files and optimizations would be profitable.

关键词： conditional entropy file access trace data access patterns caching effects

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A Secure Range Query Processing Algorithm for the Encrypted database on the Cloud 1

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11th International Scientific Conference on Future Information Technology (FutureTech) / 10th International Conference on Multimedia and Ubiquitous Engineering (MUE)

作者： Kim, Hyeong-Il Choi, Munchul Kim, Hyeong-Jin Chang, Jae-Woo Jeonbuk Natl Univ Dept Comp Engn Jeonju South Korea

ISBN: (数字)9789811015366

ISBN: (纸本)9789811015366;9789811015359

Secure range query processing algorithms have been studied as the range query can be used as a baseline technique in various fields. However, when processing a range query, the existing methods fail to hide the data access patterns which can be used to derive the actual data items and the private information of a querying issuer. The problem is that the data access patterns can be exposed even though the data and query are encrypted. So, in this paper we propose a new range query processing algorithm on the encrypted database. Our method conceals the data access patterns while supporting efficient query processing by using our proposed encrypted index search scheme. Through the performance analysis, we show that the proposed range query processing algorithm can efficiently process a query while hiding the data access patterns.

关键词： database outsourcing database encryption Encrypted index structure Secure range query processing data access patterns

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Impact of Frequency Scaling on One Sided Remote Memory accesses 9

Impact of Frequency Scaling on One Sided Remote Memory Acces...

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9th International Conference on Partitioned Global Address Space Programming Models (PGAS)

作者： Jana, Siddhartha Chapman, Barbara Univ Houston Dept Comp Sci Houston TX 77204 USA

ISBN: (纸本)9781509001859

CPU Frequency scaling is a common approach used for achieving energy savings in parallel applications. A typical approach for achieving power savings is by reducing the frequency of a processor whenever the invested CPU cycles do not contribute to the progress of an application (e.g. polling for events). Many recent research efforts have been directed towards employing this approach within HPC applications. However, one of the important challenges that have remained unexplored is its potential impact on data transfer operations within communication-intensive applications. This paper presents a detailed analysis of the impact of frequency scaling on the performance and energy efficiency of one-sided point-to-point communication within PGAS models. As an an outcome of this study, we observe that the extent of this impact depends on a number of factors like the implementation approach of a data transfer operation and the number of explicit remote transfers initiated. Besides the characteristics of the software stack, hardware features like the microarchitectural design also impact the performance of such data movement while adopting voltage scaling techniques. These inferences are supplemented with empirical analysis of common approaches of implementing remote write (PUT) operations. The empirical results presented in this paper should act as a guide for future design of software solutions targeting energy efficiency in distributed systems.

关键词： Dynamic Voltage Frequency Scaling (DVFS) Energy efficiency Energy Delay Product (EDP) Remote data Memory Acesses Energy Efficienct RDMA data access patterns OpenSHMEM PGAS

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I/O feature-based file prefetching for multi-applications

I/O feature-based file prefetching for multi-applications

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International Conference on Grid and Cloud Computing

作者： Hu, Haiyan Liu, Yi Qian, Depei School of Computer Science Beihang University Beijing 100191 China

ISBN: (纸本)9780769543130

Applications such as multimedia, date mining-and scientific computing may exhibit sophisticated data access patterns that are different from one application to another. I/O prefetching is considered to be effective in improving I/O performance. However, the efficiency depends on identification of patterns for future I/O accesses, which is difficult to achieve in multi-application environment. This paper presents the design, implementation, and evaluation of an I/O feature-based prefetching strategy (FFP) for multiple application systems. The key idea of FFP is to extract I/O features from the collected file access information to guide prefetching. We first analyzed the I/O access patterns and designed a simple and effective feature notation to represent patterns. Then we developed a toolkit to generate and update I/O features automatically. Finally, we designed and implemented an I/O feature-based file prefetching thread library for the multi-application environment. Experimental results show that the proposed prefetching mechanism (FFP) improves I/O performance significantly for applications with complex I/O data access patterns. © 2010 IEEE.

关键词： I-O feature based file prefetching thread library strategy I-O performance I/O access patterns I/O feature I/O performance I/O prefetching data access patterns multiapplication environment storage management

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