An architecture for negotiation and enforcement of resource usage policies

Advances in Cloud computing are making it possible for service providers to offer computational resources such as storage and compute power (infrastructure as a service, IaaS) to sophisticated enterprise application services (software as a service SaaS) to remote clients for a fee on a highly dynamic basis. As in any business transaction, client access to a service is regulated by a legal Service Agreement (SA). A service agreement needs to be negotiated and agreed between the provider and the client before the latter can use the service. Then on, both the client and the provider will need assurances that service interactions are in accordance with the SA, and any violations are detected and their causes identified. There is thus a need for automated support for negotiation and enforcement of service agreements. This paper discusses key design issues for such a system, of which the main one is to ensure that the policies (termed also clauses) contained in an SA are logically sound and that they work in harmony with any private policies of the client and the provider. The paper presents an architecture and a proof of concept implementation.