Towards Distributed SLA Management with Smart Contracts and Blockchain

Cloud services operate in a highly dynamic environment. This means that they need to be assorted with dynamic SLAs which explicate how a rich set of QoS guarantees evolves over time. Only in this way, cloud users will trust and thus migrate their processes to the cloud. Research-wise, SLAs are assumed to include single states while they are managed mainly in a centralised manner. This paper proposes a framework to manage dynamic SLAs in a distributed manner by relying on a rich and dynamic SLA formalism which is transformed into a smart contract. This contract is then handled via the blockchain which exploits an oracle-based interface to retrieve the off-chain cloud service context sensed and enforce the right SLA management/modification functions. The proposed framework can change the current shape of the cloud market by catering for the notion of an open distributed cloud which offers manageable and dynamic services to cloud customers enabling them to reduce costs and increase the flexibility in resource management.