• Title/Summary/Keyword: Cache Hit Ratio

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Design of Push Agent Model Using Dual Cache for Increasing Hit-Ratio of Data Search (데이터 검색의 적중률 향상을 위한 이중 캐시의 푸시 에이전트 모델 설계)

  • Kim Kwang-jong;Ko Hyun;Kim Young-ja;Lee Yon-sik
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.6 s.38
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    • pp.153-166
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    • 2005
  • Existing single cache structure has shown difference of hit-ratio according to individually replacement strategy However. It needs new improved cache structure for reducing network traffic and providing advanced hit-ratio. Therefore, this Paper design push agent model using dual cache for increasing hit-ratio by reducing server overload and network traffic by repetition request of persistent and identical information. In this model proposes dual cache structure to do achievement replace gradual cache using by two caches storage space for reducing server overload and network traffic. Also, we show new cache replace techniques and algorithms which executes data update and delete based on replace strategy of Log(Size) +LRU, LFU and PLC for effectiveness of data search in cache. And through an experiment, it evaluates Performance of dual cache push agent model.

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A Proposal for Hit Ratio Improvement of a Microprocessor's Cache Memory (마이크로프로세서 캐쉬메모리의 적중률 개선을 위한 제안)

  • 조용훈;김정선
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.4B
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    • pp.783-787
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    • 2000
  • A microprocessor, which is used as a CPU for state-of-the-art personal computers, adopts 256KB or 512KB L2(Level 2) cache memory. This cache hires Direct Mapping Procedure, 32B Line Size, and no Write Allocation. In this cache architecture, we can expert about 2.5% hit ratio improvement by using 8-way Set Associative Mapping instead of Direct Mapping, 128B Line Size instead of 32B, and Write Allocation.

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Efficient Document Replacement Policy by Web Site Popularity

  • Han, Jun-Tak
    • International Journal of Contents
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    • v.3 no.1
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    • pp.14-18
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    • 2007
  • General replacement policy includes document-based LRU or LFU technique and other various replacement policies are used to replace the documents within cache effectively. But, these replacement policies function only with regard to the time and frequency of document request, not considering the popularity of each web site. In this paper, we present the document replacement policies with regard to the popularity of each web site, which are suitable for modern network environments to enhance the hit-ratio and efficiently manage the contents of cache by effectively replacing documents on intermittent requests by new ones.

Efficient Cooperative Caching Algorithm for Distributed File Systems (분산 파일시스템을 위한 효율적인 협력캐쉬 알고리즘)

  • 박새미;이석재;유재수
    • Proceedings of the Korea Contents Association Conference
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    • 2003.11a
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    • pp.234-244
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    • 2003
  • In distributed file-systems, cooperative caching algorithm which owns the data cached at each node jointly is used to reduce an expense of disk access. Cooperative caching algorithm is the method that increases a cache hit-ratio and decrease a disk access as it holds the cache information of distributed systems in common and makes cache larger virtually. Recently, several cooperative caching algorithms decrease the message costs by using approximate information of the cache and increase the cache hit-ratio by using local and global cache fields dynamically. And they have an advantage that increases the whole field hit-ratio by sending a replaced block to the idel node on cache replacement in order to maintain the replaced block in the cache field. However the wrong approximate information deteriorates the performance, the concistency maintenance goes to great expense to exchange messeges and the cost that manages Age-information of each node to choose the idle node increases. In this thesis, we propose a cooperative cache algorithm that maintains correct cache information, minimizes the maintance cost for consistency and the management cost for cache Age-information. Also, we show the superiority of our algorithm through the performance evaluation.

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Document Replacement Policy by Site Popularity in Web Cache (웹 캐시에서 사이트의 인기도에 의한 도큐먼트 교체정책)

  • Yoo, Hang-Suk;Jang, Tea-Mu
    • Journal of Korea Game Society
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    • v.3 no.1
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    • pp.67-73
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    • 2003
  • Most web caches save documents temporarily into themselves on the basis of those documents. And when a corresponding document exists within the cache on wei s request, web cache sends the document to corresponding user. On the contrary, when there is not any document within the cache, web cache requests a new document to the related server to copy the document into the cache and then rum it back to user. Here, web cache uses a replacement policy to change existing document into a new one due to exceeded capacity of cache. Typical replacement policy includes document-based LRU or LFU technique and other various replacement policies are used to replace the documents within cache effectively. However, these replacement policies function only with regard to the time and frequency of document request, not considering the popularity of each web site. Based on replacement policies with regard to documents on frequent requests and the popularity of each web site, this paper aims to present the document replacement policies with regard to the popularity of each web site, which are suitable for latest network environments to enhance the hit-ratio of cache and efficiently manage the contents of cache by effectively replacing documents on intermittent requests by new ones.

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IT-based Technology An Efficient Global Buffer Management ,algorithm for SAN Environments (SAN 환경을 위한 효율적인 전역버퍼 관리 알고리즘)

  • 이석재;박새미;송석일;유재수;이장선
    • The Journal of the Korea Contents Association
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    • v.4 no.3
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    • pp.71-80
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    • 2004
  • In distributed file-systems, cooperative caching algorithm which owns the data cached at each node jointly is used to reduce an expense of disk access. Cooperative caching algorithm is the method that increases a cache hit-ratio and decrease a disk access as it holds the cache information of distributed systems in common and makes cache larger virtually. Recently, several cooperative caching algorithms decrease the message costs by using approximate information of the cache and increase the cache hit-ratio by using local and global cache fields dynamically. And they have an advantage that increases the whole field hit-ratio by sending a replaced buffer to the idle node on buffers replacement in order to maintain the replaced cache in the cache field. However the wrong approximate information deteriorates the performance, the consistency maintenance goes to great expense to exchange messages and the cost that manages Age-information of each node to choose the idle node increases. In this thesis, we propose a cooperative cache algorithm that maintains correct cache information, minimizes the maintenance cost for consistency and the management cost for buffer Age-information. Also, we show the superiority of our algorithm through the performance evaluation.

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Web Caching using File Type (파일 타입을 이용한 웹 캐싱)

  • Lim, Jae-Hyun;Lee, Jun-Yeon
    • The KIPS Transactions:PartC
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    • v.9C no.6
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    • pp.961-968
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    • 2002
  • This paper proposes a new access method which is to considered the high variability in World Wide Web and manage the web cache space. Instead of using a single cache, we divide a cache and store all documents according to their file types. Proposed method was compares with current cache management policies using LFU, LRU and SIZE base algorithm. Using two different workload, we show the improvement hitting ratio and byte hitting ratio through simulating on the file type caching.

Document Replacement Policy by Web Site Popularity (웹 사이트의 인기도에 의한 도큐먼트 교체정책)

  • Yoo, Hang-Suk;Chang, Tae-Mu
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.1
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    • pp.227-232
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    • 2008
  • General web caches save documents temporarily into themselves on the basis of those documents. And when a corresponding document exists within the cache on user's request. web cache sends the document to corresponding user. On the contrary. when there is not any document within the cache, web cache requests a new document to the related server to copy the document into the cache and then turn it back to user. Here, web cache uses a replacement policy to change existing document into a new one due to exceeded capacity of cache. Typical replacement policy includes document-based LRU or LFU technique and other various replacement policies are used to replace the documents within cache effectively. However. these replacement policies function only with regard to the time and frequency of document request. not considering the popularity of each web site. Based on replacement policies with regard to documents on frequent requests and the popularity of each web site, this paper aims to present the document replacement policies with regard to the popularity of each web site, which are suitable for latest network environments to enhance the hit-ratio of cache and efficiently manage the contents of cache by effectively replacing documents on intermittent requests by new ones.

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The Effects of Cache Memory on the System Bus Traffic (캐쉬 메모리가 버스 트래픽에 끼치는 영향)

  • 조용훈;김정선
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.1
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    • pp.224-240
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    • 1996
  • It is common sense for at least one or more levels of cache memory to be used in these day's computer systems. In this paper, the impact of the internal cache memory organization on the performance of the computer is investigated by using a simulator program, which is wirtten by authors and run on SUN SPARC workstation, with several real execution, with several real execution trace files. 280 cache organizations have been simulated using n-way set associative mapping and LRU(Least Recently Used) replacement algorithm with write allocation policy. As a result, 16-way setassociative cache is the best configuration, and when we select 256KB cache memory and 64 byte line size, the bus traffic ratio was decreased compared to that of the noncache system so that a single bus could support almost 7 processors without any delay and degradationof high ratio(hit ratio was 99.21%). The smaller the line size we choose, the little lower hit ratio we can get, but the more processors can be supported by a single bus(maximum 18 processors). Therefore, using a proper cache memory organization can make a single bus structure be able to support multiple processors without any performance degradation.

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Web Caching Strategy based on Documents Popularity (선호도 기반 웹 캐싱 전략)

  • Yoo, Hae-Young;Park, Chel
    • Journal of KIISE:Computer Systems and Theory
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    • v.29 no.9
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    • pp.530-538
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    • 2002
  • In this paper, we propose a new caching strategy for web servers. The proposed algorithm collects on]y the statistics of the requested file, for example the popularity, when a request arrives. And, at times, only files with higher popularity are cached all together. Because the cache remains unchanged until the cache is made newly, web server can use very efficient data structure for cache to determine whether a file is in the cache or not. This increases greatly tile efficiency of cache manipulation. Furthermore, the experiment that is performed with real log files built by web servers shows that the cache hit ratio and the cache hit ratio are better than those produced by LRU. The proposed algorithm has a drawback such that the cache hit ratio may decrease when the popularity of files that is not in the cache explodes instantaneously. But in our opinion, such explosion happens infrequently, and it is easy to implement the web servers to adapt them to such unusual cases.