Proactive SLA Negotiation for Service Based Systems: Initial Implementation and Evaluation Experience

This paper describes a framework that we have developed to integrate proactive SLA negotiation with dynamic service discovery to provide cohesive runtime support for both these activities. The proactive negotiation of SLAs as part of service discovery is necessary for reducing the extent of interruptions during the operation of a service based system when the need for replacing services in it arises. The developed framework discovers alternative candidate constituent services for a service client application, and negotiates/agrees but does not activate SLAs with these services until the need for using a service becomes necessary. A prototype tool has been implemented to realize the framework. This prototype is discussed in the paper along with the results of the initial evaluation of the framework.