Cost-effective configuration of content resiliency services under correlated failures

Abstract

Value-added content resiliency services help to migrate the burden of resiliency provisioning and maintenance from service users, especially home users and small/medium organizations, who have dif culty in handling correlated failures that impact large areas. For service providers to achieve business success, however, the cost-effectiveness of their resiliency strategies is critical: while the content resiliency requirements speci ed by the end users have to be satis ed, excessive preventive operation costs caused by the over-reaction to potential risks should be avoided. In this paper, we study the problem of cost-effective con guration in content resiliency service networks under both independent and geographically correlated failures. We propose a new approach to modeling correlated failures in a representable, quanti able and consistent way, which allows for both quanti ed availability guarantees and aggressive prevention cost optimization. We then formulate the cost-effective con guration problem in content resiliency services and develop both real optimal and heuristic-based algorithms for solving the problem. Our experiments show that with the help of good models for correlated failures, the operation cost of the services can be signi cantly reduced without impairing the user-sped ed content resiliency. © 2006 IEEE.