Algorithms for Content Distribution in Networks

Abstract

In this paper an algorithm is presented which helps us to optimize the performance of content distribution servers in a network. If it is following the pay-as-you-use model then this algorithm will result in significant cost reduction. At different times the demand of different kind of content varies and based on that number of servers who are serving that demand will vary. The problem of content distribution in Networks is defined in the context of demand and supply paradigm. There may be downloadable software with a considerable size. At peak loads 10,000 persons may be downloading that software at the same time. However, downloads will come to an average number of 15, 00 downloads at any given point of time. Whenever the new versions of that software are launched, peak is again reached. There can be a number of such software downloads that you want to make available through your website. The demands will also be coming from different regions and different IP addresses. There will be certain pattern that can be found out by the analysis. These demand number will also keep on changing based on the time of the day in that region. The distance of the servers from that client who is requesting the software is crucial in determining the time taken to download that software. Overall performance of the site in terms of average time being taken to download one software is crucial to the image and working of the company. This is a dynamic problem, where new servers need to be made active once the active server reaches a threshold value. Similarly once there is a drop in demand from a particular region, than the server servicing that region must be relieved from service to save money. The input in this kind of problem is given in terms of a matrix containing the cost of opening of each server location and a set of locations generating the demand.(1-4) The demands from the clients will come one by one in the form of the http request and must be handled by our algorithm. These client demands must be assigned to some server based on the location of that client and the nearest server from that position. However, it is not possible to open a new or passive demand location for a few demands. In that case these demands will be transferred to the nearest active server. When the new demands crosses a particular threshold then only new service points can be opened. In Incremental Content Distribution Algorithm when an existing server serves number of clients less than a defined value then that server is stopped and existing demand services are transferred to another content distribution servers.