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GEMA: An object replacement algorithm for cooperative web proxy systems

MULTIMEDIA TOOLS AND APPLICATIONS 2004年第2期23卷 103-130页

作者： Dong, LG Veeravalli, B Hangzhou Univ Commerce Hangzhou 310035 Zhejiang Peoples R China Natl Univ Singapore Open Source Software Lab Singapore 119260 Singapore

In this paper, we design and analyze a web object replacement algorithm, referred to as gain-based exchange and migration algorithm (GEMA) suitable for a cooperative World Wide Web proxy caching environment. In a cooperative environment where more than one proxy exists, the replacement algorithms used for single system cache cannot not be directly put in use to achieve an acceptable performance. In this paper, we first present an analytical model, which quantifies the "importance", referred to as object-caching gain, of an object at a cache. This gain is used in making replacement decisions and considers the benefit of caching at local as well as neighboring proxies. Our model efficiently exploits the advantages present in the existing the research contributions on designing replacement strategies for the single-cache environment. Further, with this model, we introduce two basic powerful primitive operations, namely the object exchange and object migration, to improve an overall performance. These two operations are carried out as an outcome of replacement decisions based on the comparison of gains among objects. Thus, the calculation of the gain and deciding on which of the operations to use constitute the main part of our algorithm GEMA. For quantifying the performance of GEMA, we carry out rigorous simulation experiments based on trace-driven and event-driven approaches. Using the event-driven simulation, we comprehensively testify the performance improvement of GEMA under a variety of performance measures such as, average access time of web objects, hit ratio, and byte hit ratio. We compare and analyze our strategies with some of the popular strategies found in the literature. We also highlight some possible extensions to the research contributions in this paper.

关键词： WWW web caching replacement algorithm cooperative caching proxy caching

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Power-Aware replacement algorithm to Deliver Dynamic Mobile Contents

Power-Aware Replacement Algorithm to Deliver Dynamic Mobile ...

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International Conference on Life System Modeling and Simulation / International Conference on Intelligent Computing for Sustainable Energy and Environment (LSMS-ICSEE)

作者： Su, Zhou Zhang, Zhihua Waseda Univ Fac Sci & Engn Ohkubo3-4-1 Tokyo Japan Sanyo Women Coll Dept Human Life Stud Hiroshima Japan

ISBN: (纸本)9783642158520

As more and more users are using wireless network to access Web contents, the power awareness issue becomes one of the most important concerns for Mobile contents delivery networks (MCDN). Unnecessary power dissipation always brings the disconnection and delay during the time of wireless access. replacement algorithm is looked upon as one solution to resolve this problem. However, most of the current replacement algorithms have not been taken the power-awareness into consideration. Therefore, in this paper we design a new method where a novel power-aware algorithm is proposed. Both theory analysis and simulations improve that our proposal can outperform other conventional methods.

关键词： Mobile Contents Contents Processing Network Architecture Power Aware replacement algorithm

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An Enhanced Semantic-based Cache replacement algorithm for Web Systems

An Enhanced Semantic-based Cache Replacement Algorithm for W...

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IEEE - RIVF International Conference on Computing and Communication Technologies (RIVF)

作者： Xuan Tung Hoang Ngoc Dung Bui VNU Univ Engn & Technol Fac Informat Technol Hanoi Vietnam Univ Transport & Commun Fac Informat Technol Hanoi Vietnam

ISBN: (纸本)9781538693131

As Web traffics is increasing on the Internet, caching solutions for Web systems are becoming more important since they can greatly expand system scalability. An important part of a caching solution is cache replacement policy, which is responsible for selecting victim items that should be removed in order to make space for new objects. Typical replacement policies used in practice only take advantage of temporal reference locality by removing the least recently/frequently requested items from the cache. Although those policies work well in memory or filesystem cache, they are inefficient for Web systems since they do not exploit semantic relationship between Web items. This paper presents a semantic-aware caching policy that can be used in Web systems to enhance scalability. The proposed caching mechanism defines semantic distance from a web page to a set of pivot pages and use the semantic distances as a metric for choosing victims. Also, it use a function-based metric that combines access frequency and cache item size for tie-breaking. Our simulations show that out enhancements outperform traditional methods in terms of hit rate, which can be useful for websites with many small and similar-in-size web objects.

关键词： web cache replacement algorithm semantic-aware semantic distance web performance

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An Aggregation Cache replacement algorithm Based on Ontology Clustering

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Wuhan University Journal of Natural Sciences 2006年第5期11卷 1141-1146页

作者： ZHU Jiang SHEN Qingguo TANG Tang LI Yongqiang Institute of Communications Engineering PLAUniversity of Science and Technology Nanjing. 210007Jiangsu China

This paper describes the theory, implementation, and experimental evaluation of an Aggregation Cache replacement （ ACR ） algorithm. By considering application background, carefully choosing weight values, using a special formula to calculate the similarity, and clustering ontologies by similarity for getting more embedded deep relations, ACR combines the ontology similarity with the value of object and decides which object is to be replaced. We demonstrate the usefulness of ACR through experiments. （a） It is found that the aggregation tree is created wholly differently according to the application cases. Therefore, clustering can direct the content adaptation more accurately according to the user perception and can satisfy the user with different preferences. （b） After comparing this new method with widely-used algorithm Last-Recently-Used （LRU） and First-in-First-out （FIFO） method, it is found that ACR outperforms the later two in accuracy and usability. （c） It has a better semantic explanation and makes adaptation more personalized and more precise.

关键词： ontology similarity replacement algorithm content adaptation semantic Web

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New proxy replacement algorithm for multimedia streaming

New proxy replacement algorithm for multimedia streaming

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Conference on Multimedia Systems and Applications IV

作者： Wong, HL Lo, KT Hong Kong Polytech Univ Dept Elect & Informat Engn Ctr Multimedia Signal Proc Hong Kong Hong Kong Peoples R China

ISBN: (纸本)0819442429

Proxy servers play an important role in between servers and clients in various multimedia systems on the Internet. Since proxy servers do not have an infinite-capacity cache for keeping all the continuous media data, the challenge for the replacement policy is to determine which streams should be cached or removed from the proxy server. In this paper, a new proxy replacement algorithm, named the Least Popular Used (LPU) caching algorithm, is proposed for layered encoded multimedia streams in the Internet. The LPU method takes both the short-term and long-term popularity of the video into account in determining the replacement policy. Simulation evaluation shows that our proposed scheme achieves better results than some existing methods in term of the cache efficiency and replacement frequency under both static and dynamic access environments.

关键词： poxy caching layered encoded stream stream popularity stream life cycle replacement algorithm

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Red: An Efficient replacement algorithm Based on REsident Distance for Exclusive Storage Caches

Red: An Efficient Replacement Algorithm Based on REsident Di...

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26th Symposium on Mass Storage Systems and Technologies (MSST)

作者： Zhao, Yingjie Xiao, Nong Liu, Fang Natl Univ Def Technol Dept Comp Sci Changsha Hunan Peoples R China

ISBN: (纸本)9781424471539

This paper presents our replacement algorithm named RED for storage caches. RED is exclusive. It can eliminate the duplications between a storage cache and its client cache. RED is high performance. A new criterion Resident Distance is proposed for making an efficient replacement decision instead of Recency and Frequency. Moreover, RED is non-intrusive to a storage client. It does not need to change client software and could be used in a real-life system. Previous work on the management of a storage cache can attain one or two of above benefits, but not all of them. We have evaluated the performance of RED by using simulations with both synthetic and real-life traces. The simulation results show that RED significantly outperforms LRU, ARC, MQ, and is better than DEMOTE, PROMOTE for a wide range of cache sizes.

关键词： exclusive caching replacement algorithm resident distance

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An Efficient Page replacement algorithm for PCM-based Mobile Embedded Systems 17

An Efficient Page Replacement Algorithm for PCM-based Mobile...

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17th IEEE/ACIS International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing (SNPD)

作者： Yoo, Seunghoon Bahn, Hyokyung Seoul Natl Univ Sch Comp Sci & Engn Seoul South Korea Ewha Womans Univ Dept Comp Engn Seoul South Korea

ISBN: (纸本)9781509022397

Traditional embedded systems do not use virtual memory swapping but load the entire footprint into memory as they are usually single task special-purpose machines. Recently, as mobile embedded systems support multi-tasking, the necessity of swapping is becoming increasingly important. However, current mobile systems such as smartphones do not support swapping because flash memory has weaknesses to be a swap device in such environments. More recently, phase-change memory (PCM) emerges as an alternative medium for the swap device of mobile embedded systems. In this paper, we present a new page replacement algorithm for a mobile embedded system that uses PCM as a swap device. Although PCM provides high performance and byte-accessibility, its write operation is slow and it accommodates only limited endurance cycles. To cope with this situation, our algorithm tracks the dirtiness of a page at the granularity of a sub-page and replaces the least dirty page among pages not recently used, leading to reduced write traffic to PCM. Experimental results with various mobile workloads show that the proposed algorithm reduces the amount of data written to PCM by 24% on average and up to 74% compared to the well-known CLOCK algorithm. It also extends the lifetime of PCM by 50% on average.

关键词： Phase-change memory swap device replacement algorithm virtual memory CLOCK

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LIRS2: An improved LIRS replacement algorithm 21

LIRS2: An improved LIRS replacement algorithm

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14th ACM International Conference on Systems and Storage, SYSTOR 2021

作者： Zhong, Chen Zhao, Xingsheng Jiang, Song University of Texas at Arlington ArlingtonTX United States

ISBN: (纸本)9781450383981

A block replacement algorithm keeps receiving attention on improvement of its hit ratio. Many replacement algorithms have been proposed, among which LIRS stands out with its consistently higher hit ratio across various workloads with low time and space overheads. However, there are still access patterns where LIRS produces sub-optimal hit ratio and has room for further improvement. In this paper, we replace the locality measure used by LIRS, the reuse distance, with a more stable and thus more reliable measure, to predict future access time. The new measure is the sum of a block's two recent consecutive reuse distances. It addresses the issue with the reuse distance, which is more likely to fluctuate and mislead replacement decisions. We proposed LIRS2 by incorporating this new measure into the LIRS algorithm to reduce its miss ratio. We further propose a replacement design that allows a responsive adaptation between LIRS2 and LRU so that LRU-friendly access patterns can be well accommodated. We have implemented LLRS2 and its adaptive variant. With extensive experiments on traces from different sources, we show that the algorithms can consistently improve cache miss ratio with low overheads. © 2021 Owner/Author.

关键词： storage system replacement algorithm cache

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An effective, low-overhead, improved replacement algorithm for mail service applications in storage system

An effective, low-overhead, improved replacement algorithm f...

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IEEE International Symposium on Parallel and Distributed Processing With Applications

作者： Si, Chengxiang Meng, Xiaoxuan Chen, Yuanfei Xu, Lu Institute of Computing Technology Chinese Academy of Sciences Graduate School of the Chinese Academy of Sciences Beijing China Institute of Computing Technology Chinese Academy of Sciences Beijing China

ISBN: (纸本)9780769541907

This paper analyzed the performance characteristics of classic 2Q algorithm when it was performed on mail-service workloads, and proposes an improved algorithm, called 2Q*. The simulation results show that 2Q* algorithm can outperform the other replacement algorithms, including the classic 2Q algorithm, for all the cache sizes and various mail-service workloads. To verify the simulation results in real system, we integrated the algorithm into FlexiCache, a partitioned buffer cache system, and joined it with a popular adaptive sequential pre-fetch policy properly. The experiment results verify the effectiveness of 2Q* algorithm for mail service applications. By joint with the prefetch policy, the performance is further improved. Moreover, its runtime overhead is also fairly low. © 2010 IEEE.

关键词： 2Q algorithm FlexiCache cache cache storage electronic mail mail service mail service applications partitioned buffer cache system prefetch policy replacement algorithm replacement algorithms storage system

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Inter-reference gap distribution replacement: an improved replacement algorithm for set-associative caches 04

Inter-reference gap distribution replacement: an improved re...

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Proceedings of the 18th annual international conference on Supercomputing

作者： Masamichi Takagi Kei Hiraki University of Tokyo

ISBN: (纸本)9781581138399

We propose a novel replacement algorithm, called Inter-Reference Gap Distribution replacement (IGDR), for set-associative secondary caches of processors. IGDR attaches a weight to each memory-block, and on a replacement request it selects the memory-block with the smallest weight for eviction. The time difference between successive references of a memory-block is called its Inter-Reference Gap (IRG). IGDR estimates the ideal weight of a memory-block by using the reciprocal of its *** estimate this reciprocal, it is assumed that each memory-block has its own probability distribution of IRGs; from which IGDR calculates the expected value of the reciprocal of the IRG to use as the weight of the memory-block. For implementation, IGDR does not have the probability distribution; instead it records the IRG distribution statistics at run-time. IGDR classifies memory-blocks and records statistics for each class. It is shown that the IRG distributions of memory-blocks correlate their reference counts, this enables classifying memory-blocks by their reference counts. IGDR is evaluated through an execution-driven simulation. For ten of the SPEC CPU2000 programs, IGDR achieves up to 46.1% (on average 19.8%) miss reduction and up to 48.9% (on average 12.9%) speedup, over the LRU algorithm.

关键词： set-associative cache replacement algorithm cache memory

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