Reliable Orchestration of Resources Using WS-Agreement

Co-ordinated usage of resources in a Grid environment is a challenging task impeded by the nature of resource usage and provision: Resources reside in different geographic locations, are managed by different organisations, and the provision of reliable access to these resource usually has to be negotiated and agreed upon in advance. These prerequisites have to be taken into account providing solutions for the orchestration of Grid resources. In this document we describe the use of WS-Agreement for Service Level Agreements paving the way for using multiple distributed resources to satisfy a single service request. WS-Agreement is about to be released as a draft recommendation of the Global Grid Forum and has already been implemented in a number of projects, two of which we will presented in this paper.