Consistency and Safe Caching in Distributed File System by Using Lease Based Mechanism

In this paper, we argue that weak cache consistency and unsecured caching in distributed file system environment supported by existing mechanism and protocol, and must be augmented by strong consistency mechanisms and protocol to support the growing diversity in application requirements. There are many methods to maintain consistency in the distributed file system but provides weak consistency. But one method provides strong consistency and safe caching as well in the distributed environment is the lease method and it also provide safe caching in distributed environment. During the proxy's lease time from a web server, the web server can notify the modification to the proxy by invalidation or update. In this paper, we have shown some analysis parameter. By using these analyses, we can choose the adaptive lease time and proper protocol (invalidation or update scheme of the modification for each proxy in the distributive file environment). As the number of proxies for web caching increases exponentially, a more efficient method for maintaining consistency needs to be designed.