Demand Based File Replication and Consistency Mechanism

File replication and consistency are well known techniques in distributed systems to address the key issues such as scalability, reliability and fault tolerance. For many years, file replication and consistency in distributed environment has been researched to enhance and optimize the availability and reliability of the entire system. An effort has been made in the present work to propose a file popularity based, adaptive, on demand, reliable and comprehensive file replication and consistency mechanism. This paper introduces a group of File Replication Servers (FRS) that is responsible for ensuring the file availability, in order to fulfill the file request. The present work proposes Hybrid file update propagation mechanism so as to minimize the number of updates. Proposed model replicates the file, from one node to the other node, when the total number of request for a particular file reaches a threshold value. Proposed approach is implemented on JAVA platform. Based on the file popularity, model creates and updates the file replica on the server. The proposed Hybrid approach is compared with write invalidate and write update propagation policies. Comparison results show that for balanced load hybrid file update propagation model updates the optimum number of replicas. Whereas, for unbalanced load, hybrid approach outperforms other two approaches by handling all the file requests with minimum number of updates.