Agent Based Efficient Consistency Control and Replica Management in Data Grids

Abstract

Data Grids provide services and infrastructure for distributed data-intensive applications accessing massive geographically distributed datasets. An important technique to speed up the access to _les in data grids is replication, which create multiple copies of a file. The work presented in this dissertation is focused on the problem area of data grids, mainly on the challenges posed by data replication. The distinct problem areas addressed in this work are efficient management of replica and consistency management. Therefore, to achieve the set objectives of proposed work, an extensive literature review on replica management has been done. The state of the art techniques in the area of replica manageable in data grid have been explored. The comprehensive study of asynchronous replica management in data grids has been carried out to identify their inherent limitations. From the literature survey, it is apparent that the biggest challenge confronting data grid is related to replica creation, placement, selection and consistency maintenance. To address the replica management challenge, an agent based model, namely Replica Management Modelquot (RMM), has been proposed and implemented for efficient management of distributed files across the data grid. The model considers various characteristics of data grid such as scalability, availability, and dynamic nature. The model is layered in nature. The proposed model divides the entire functionality across the different layers. The layered architecture bears negligible overhead in terms of communication cost. Evaluation of the proposed hierarchical model is done on two factors: (i) topology and (ii) availability. The performance analysis of the proposed model has been carried out in simulated environment. The comparative analysis of the hierarchical approach with centralized approach has shown that RMM model provide more scalability in the system.