Autonomous Agreement-Mediation Based on WS-agreement for Improving Cloud SLAs

The management of today´s service level agreements on the cloud market is often nontransparent and ineffective for the customer and the provider. However, service level agreements are crucial for establishing trust between all participants, especially for companies whose success depends on the purchased cloud service with its appropriated service quality. This paper introduces a concept for an Agreement-Mediator that acts as a neutral and autonomous entity in the cloud market. The language and protocol for searching, negotiating, and establishing service level agreements is the WS-Agreement standard and its extension WS-Agreement-Negotiation. This mediator aims to increase efficiency and effectiveness of service level agreements as well as transparency for customers. This paper describes the Agreement-Mediator´s architecture and illustrates its functionalities and workflows. Furthermore, we show how the WS-Agreement and the WS-Agreement-Negotiation standards are used and which improvements are required for managing service level agreements in an autonomous entity.