Consistency as a Service: Auditing Cloud Consistency

Consistency as a Service: Auditing Cloud Consistency

ABSTRACT:

Cloud storage services have become commercially popular due to their overwhelming advantages. To provide ubiquitous always-on access, a cloud service provider (CSP) maintains multiple replicas for each piece of data on geographically distributed servers. A key problem of using the replication technique in clouds is that it is very expensive to achieve strong consistency on a worldwide scale. In this paper, we first present a novel consistency as a service (CaaS) model, which consists of a large data cloud and multiple small audit clouds. In the CaaS model, a data cloud is maintained by a CSP, and a group of users that constitute an audit cloud can verify whether the data cloud provides the promised level of consistency or not. We propose a two-level auditing architecture, which only requires a loosely synchronized clock in the audit cloud. Then, we design algorithms to quantify the severity of violations with two metrics: the commonality of violations, and the staleness of the value of a read. Finally, we devise a heuristic auditing strategy (HAS) to reveal as many violations as possible. Extensive experiments were performed using a combination of simulations and realcloud deployments to validate HAS.

EXISTING SYSTEM:

Ø By using the cloud storage services, the customers can access data stored in a cloud anytime and anywhere using any device, without caring about a large amount of capital investment when deploying the underlying hardware infrastructures.

Ø The cloud service provider (CSP) stores data replicas on multiple geographically distributed servers.

Ø Where a user can read stale data for a period of time. The domain name system (DNS) is one of the most popular applications that implement eventual consistency. Updates to a name will not be visible immediately, but all clients are ensured to see them eventually.

DISADVANTAGES OF EXISTING SYSTEM:

Ø The replication technique in clouds is that it is very expensive to achieve strong consistency.

Ø Hard to verify replica in the data cloud is the latest one or not.

PROPOSED SYSTEM:

Ø In this paper, we presented a consistency as a service (CaaS) model and a two-level auditing structure to help users verify whether the cloud service provider (CSP) is providing the promised consistency, and to quantify the severity of the violations, if any.

Ø With the CaaS model, the users can assess the quality of cloud services and choose a right CSP among various candidates, e.g, the least expensive one that still provides adequate consistency for the users’ applications.

ADVANTAGES OF PROPOSED SYSTEM:

Ø Do not require a global clock among all users for total ordering of operations.

Ø The users can assess the quality of cloud services.

Ø choose a right CSP

Ø Among various candidates, e.g, the least expensive one that still provides adequate consistency for the users’ applications.

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

Ø System                          :         Pentium IV 2.4 GHz.

Ø Hard Disk                      :         40 GB.

Ø Floppy Drive                 :         1.44 Mb.

Ø Monitor                         :         15 VGA Colour.

Ø Mouse                            :         Logitech.

Ø Ram                               :         512 Mb.

SOFTWARE REQUIREMENTS:

Ø Operating system           :         Windows XP/7.

Ø Coding Language :         ASP.net, C#.net

Ø Tool                     :         Visual Studio 2010

Ø Database              :         SQL SERVER 2008

REFERENCE:

Qin Liu, Guojun Wang, and Jie Wu, “Consistency as a Service: Auditing Cloud Consistency”, IEEE TRANSACTIONS ON NETWORK AND SERVICE MANAGEMENT, VOL. 11, NO. 1, MARCH 2014