Preserving Cloud Consistency Using Caas Model

1 Mphil Scholar, 2 Assistant Professor, Department Of Computer Science , Nadar Saraswathi College (India) ABSTRACT Cloud storage services are commercially more popular due to their amount of advantages. Most of the cloud service provider provides services like infrastructure management, data storage services on 24/7 through any devices at anywhere. To provide this ubiquitous always on service most of the cloud service provider (CSP) maintains each piece of data on geographically distributed servers. The main key problem with this technique is that, it is very expensive and some to fail to provide required consistency of service. To overcome this problem, we propose to use a new approach of service (i.e. Consistency as a Service(CaaS)) this paper, firstly concentrate on a consistency as a service (CaaS) model, which has a large data cloud and multiple small audit clouds. In the CaaS model, a data cloud is formed by a CSP, and a group of users form an audit cloud that can verify whether the data cloud provides the promised level of consistency i.e. quality of service or not, for that make use of two-level auditing strategy which require loosely synchronized clock for ordering operations in an audit cloud. Then perform global auditing by global trace of operations through randomly electing an auditor from an audit cloud. Finally, use a heuristic auditing strategy(HAS) to display as many violations as possible.