AN IMPROVED ALGORITHM FOR REPLICATION OF VIDEO FILES IN A DISTRIBUTED ENVIRONMENT

Abstract

The per service cost hasp been serious impediment to wide spread usage of on-line digital continuous media service, especially in the entertainment arena. Although handling the continuous media may be achievable due to the technology advances in past few years, its competitiveness in the market with the existing service type such as video rental is still in question. In this thesis, We propose an algorithm for reducing the cost of resources used(storage and network) . for continuous media service in a distributed infrastructure. The distributed infrastructure consists of massive scale continuous media server called a video warehouse, and intermediate storages. These are connected via high speed communication network. An intermediate storage is located in each neighborhood,, and its main purpose is to avoid the repeated delivery of the same file to a neighborhood. The storage resource and network resource to support a set of requests should be properly quantified to a uniform metric to measure the efficiency of the service schedule. We first developed a cost model which maps the given service schedule to a quantity. We then use this cost model to capture the amortized resource requirement of the schedule. We propose to keep the video files (hot files) at intermediate storage for some extra time after the service of current request is complete. This enables the service of a future request arrived during that time, directly from intermediate storage and saves the network charges. In our model the request for a video file is given sometime in advance. The algorithm, strategically replicates the requested continuous media files at the various intermediate storages to reduce the total service cost (network cost and storage cost).