A New Environment for Web Caching and Replication Study (original) (raw)
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A Proposed Model for Web Proxy Caching Techniques to Improve Computer Networks Performance
International Journal of Information Technology and Computer Science, 2013
one of the most important techniques for improving the performance of web based applications is web proxy caching Technique. It is used for several purposes such as reduce network traffic, server load, and user perceived retrieval delays by replicating popular content on proxy caches that are strategically placed within the network. The use of web proxy caching is important and useful in the government organizations that provides services to citizens and has many branches all over the country where it is beneficial to improve the efficiency of the computer networks performance, especially remote areas which suffer from the problem of poor network communication. Using of proxy caches provides all users in the government computer networks by reducing the amount of redundant traffic that circulates through the network. It also provides them by getting quicker access to documents that are cached. In addition, there are a lot of benefits we can obtain from the using of proxy caches but we will address them later. In this research, we will use web proxy caching to provide all of the above benefits that we are mentioned above and to overcome on the problem of poor network communication in ENR (Egyptian National Railways). We are going to use a scheme to achieve the integration of forward web proxy caching and reverse proxy caching.
PROXY BASED WEB CACHE CONSISTENCY FOR ENHANCING NETWORK EXECUTION
With the exponential growth of the Internet, the World Wide Web (WWW) has become the most widely used tool for access and dissemination of commercial educational, and news information on the internet. The success of the WWW is largely due to its cap ability of providing quick and easy accesses to a large variety of information form sites all over the world. The retrieval latency of the WWW is however sensitive to overload conditions of the network which agonizes web users. Caching data copies at client Sites (including web proxies) is regarded as a good technique for reducing both the network traffic and the server load, thus improving retrieval latency of web documents. Use of proxy caches in the World Wide Web is beneficial to the end user, network administrator, and server administrator since it reduces the amount of redundant traffic that circulates through the network. In addition, end users get quicker access to documents that are cached. However, the use of proxies introduces additional issues that need to be addressed. The existing consistency protocols used in the web are proving to be insufficient to meet the growing needs of the Internet population. For example, too many messages sent over the network are due to caches guessing when their copy is inconsistent. Many decisions must be made when exploring World Wide Web coherency, such as whether to provide consistency at the proxy level (client pull) or to allow the sever to handle it (server push). What tradeoffs are inherent for each of these decisions? The relevant usage of any method strongly depends upon the conditions of the network (e.g., document types that are frequently requested or the state of the network load) and the resources available (e.g., disk space and type of cache available). One goal of this dissertation is to study the characteristics of document retrieval and modification to determine their effect on proposed consistency mechanisms. A set of effective consistency policies is identified from the investigation. The main objective of this dissertation is to use these findings to design and implement a consistency algorithm that provide improved performance over the current mechanisms. Optimistically, we want an algorithm that provides strong consistency. However, we do not want to further degrade the network or cause undue burden on the server to gain this advantage. We propose a system based on the notion of soft-state and based on server push. In this system, the proxy would have some influence on what state information. Our results show that an average of 20% control message savings by limiting how much polling occurs with the current Web cache consistency mechanism, Adaptive Client Polling.
Proxy Cache Algorithms: Design, Implementation, and Performance
ÐCaching at proxy servers is one of the ways to reduce the response time perceived by World Wide Web users. Cache replacement algorithms play a central rolfe in the response time reduction by selecting a subset of documents for caching, so that a given performance metric is maximized. At the same time, the cache must take extra steps to guarantee some form of consistency of the cached documents. Cache consistency algorithms enforce appropriate guarantees about the staleness of the cached documents. We describe a unified cache maintenance algorithm, LNC-R-W3-U, which integrates both cache replacement and consistency algorithms. The LNC-R-W3-U algorithm evicts documents from the cache based on the delay to fetch each document into the cache. Consequently, the documents that took a long time to fetch are preferentially kept in the cache. The LNC-R-W3-U algorithm also considers in the eviction consideration the validation rate of each document, as provided by the cache consistency component of LNC-R-W3-U. Consequently, documents that are infrequently updated and thus seldom require validations are preferentially retained in the cache. We describe the implementation of LNC-R-W3-U and its integration with the Apache 1.2.6 code base. Finally, we present a trace-driven experimental study of LNC-R-W3-U performance and its comparison with other previously published algorithms for cache maintenance. Index TermsÐProxy, caching, cache replacement, cache consistency, World Wide Web.
A Windows Based Web Cache Simulator Tool
Proceedings of the First International ICST Conference on Simulation Tools and Techniques for Communications Networks and Systems, 2008
In this paper, we describe a Windows based Web cache simulator tool. This tool is able to process the IRCache based traces files and reproduce the behavior of a Web Proxy Cache. It can be configured to simulate fifteen replacement policies and two admission control policies. The cache size, the percentage of warm-up and the cost function of some replacement policies can also be configured. The simulations can be performed in a batch process and the results are stored in text format files that can be automatically analyzed using other tools like Matlab to obtain performance graphs.
Web caching framework: analytical models and beyond
Proceedings 1999 IEEE Workshop on Internet Applications (Cat. No.PR00197)
Many web caching algorithms have been proposed in recent years. However, the lack of analytical support and systematic evaluation environment significantly affect the applicability of these algorithms. In this paper, we introduce a framework within which web caching algorithms can be consistently analyzed and empirically examined. The framework consists of two complementary parts: The statistical model and the simulation environment. The analytical model covers both the web trace characteristics and the caching algorithm behaviors. The simulation system, referred to as WebCASE(Web Caching Algorithm Simulation Environment), consists of an extensible simulation core and a front end graphical interface showing the running algorithm behaviors. By using this framework, we are able to better understand the performance discrepancies exhibited by different algorithms and develop more efficient new algorithms. These new algorithms take into consideration practical issues and make noticeable performance improvements over existing algorithms.
A new approach for a proxy-level web caching mechanism
Decision Support Systems, 2008
In this study we propose a new proxy-level web caching mechanism that takes into account aggregate patterns observed in user object requests. Our integrated caching mechanism consists of a quasi-static portion that exploits historical request patterns, as well as a dynamic portion that handles deviations from normal usage patterns. This approach is more comprehensive than existing mechanisms because it captures both the static and the dynamic dimensions of user web requests. The performance of our mechanism is empirically tested against the popular least recently used (LRU) caching policy using an actual proxy trace dataset. The results demonstrate that our mechanism performs favorably versus LRU. Our caching approach should be beneficial for computer network administrators to significantly reduce web user delays due to increasing traffic on the Internet.
2003
Designing new network protocols for the Internet relies on the use of network simulation tools for validation. When simulation is aimed at testing the scalability of new protocols, working with large-scale realistic topologies is of paramount importance. In this paper we present an extension of the NAM Editor, a graphical editor to be used in conjunction with the well-known ns2 network simulator. Our extended NAM Editor allows the creation of synthetic but realistic network simulation scenarios and provides support for the simulation of web caching systems.
Efficient Web Content Delivery Using Proxy Caching Techniques
IEEE Transactions on Systems Man and Cybernetics Part C (Applications and Reviews)
Web caching technology has been widely used to improve the performance of the Web infrastructure and reduce userperceived network latencies. Proxy caching is a major Web caching technique that attempts to serve user Web requests from one or a network of proxies located between the end user and Web servers hosting the original copies of the requested objects. This paper surveys the main technical aspects of proxy caching and discusses recent developments in proxy caching research including caching the "uncacheable" and multimedia streaming objects, and various adaptive and integrated caching approaches. Index Terms-Caching performance evaluation, dynamic content caching, proxy caching, Web caching. I. INTRODUCTION T HE AMOUNT of traffic over the Internet has experienced tremendous growth in recent years largely due to the wide adoption of the World Wide Web technologies and the resulting explosion of Web-based content development and dissemination [1]-[3]. The Internet bandwidth capacity expansion, on the other hand, is lagging behind, making the Web a major performance bottleneck. The gap between the Web infrastructure capacity and demand will continue to exist, ifnot expand, as information search and business transactions are being increasingly conducted over the Web. Another compounding factor is related to the recent developments in the Web technologies such as Web services, which will potentially bring in new classes of distributed applications in large numbers that will communicate among one another over the Internet, consuming network bandwidth [4]. Web caching is an established approach to meet the important Web capacity challenge and address related issues such as user-perceived network latencies. Broadly speaking, caching can be defined as serving user Web requests from places other Manuscript
Performance Comparison of a Web Cache Simulation Framework
Advanced Information Networking and Applications, 2005
Performance comparison studies are primarily carried out through real systems or simulation environments. Simulation is the most commonly used method to explore new proposals due to both its flexibility and the relatively reduced time taken to obtain performance results. This paper presents a powerful framework to simulate Web proxy cache systems. Our tool provides a comfortable environment to simulate and explore cache management techniques. In order to validate our framework and show how accurate it executes, a performance comparison has been done. We analyzed the details of a commercial proxy cache system and compare its results with those obtained from our simulator using the most commonly replacement algorithm (LRU). For this purpose, the proposed environment was adapted to match the performance of the real proxy cache. Experimental results show that proxy cache hit ratio deviations fall very close to the real system, since then, never exceeds 3.42%.
Various Techniques used to Improve the Performance of Proxy Caching
2019
Proxy caching is utilized to increase access of user to general web content. Multiple system utilizes multiple cache for well performance. Cache of Multi-level usually works via testing the minimum lead cache. Uncertainty you miss a minor cache than the next vast level cache. This paper will study L1 cache such as the primary memory with L2 cache like the secondary form of memory of the proxy server. LRU takes into account the replacement of page algorithm. Previously, LRU technique used to eliminate the cold caching pollution. But it is not much efficiently work so we overcome this problem. In this paper, there we used three techniques such as LRU, AVL Tree and Binary Search Tree. The performance has been done over these techniques on the basis of access time. The result shows in the form of tables and graphs that shows, AVL tree is best among these techniques. Keywords—Proxy Server, LRU, AVL tree, Binary Search Tree, Access time.