SAMI: The SLA Management Instance

The vision for economies of reusable services that can be composed into business processes is still hindered by the lack of dependability as regards their execution. Service Level Agreements (SLAs) are an instrument to express and codify requirements for services, so that an acceptable level of determinism can be provided, and customers can rely on them as such. In this work we present the SLA Management Instance (SAMI) architecture for a reusable autonomic entity that can support negotiation and runtime management of SLAs, without disruptive effects on the existing corresponding services. This architecture takes extra steps towards supporting hierarchies of cross-domain SLAs, reflecting similar hierarchies of cross-domain service compositions.