Decentralized Cloud Computing

This thesis proposes a decentralized Cloud platform, where Services can use infrastructure and hardware accelerators from a network of private compute resources managed through Smart Contracts deployed on a public Blockchain. This is achieved by leveraging and extending existing open-source technologies for Cloud Orchestration and designing a decentralized resource selection mechanism and scheduling protocols for resource allocation. The decentralized resource selection mechanism is facilitated by a Smart Contract on a public Blockchain and a Self-Organizing Self-Managing Resource Management System. The main contribution of this part is the investigation of the operational constraints and costs associated with outsourcing the selection logic to the Smart Contract. Moreover, the selection mechanism is optimized to increase the throughput of scheduling decisions. The platform allows for the definition, composition, optimization, and deployment of Cloud Services. It improves the state of the art by allowing a user to design applications composed of abstract services, for which explicit implementations and resources are selected by our platform, depending on the user constraints and resource availability. This contribution improves the flexibility of both the Cloud user and the Cloud provider, allowing for a more efficient Cloud. The novel resource management framework allows for the self-organization of collaborative resource management components. Each component makes use of a Suitability Index in order to take self-organization decisions and guide resource requests to the most suitable resource given the system state. Experimental evaluation shows that a small provisioning delay is incurred by our System compared to traditional on-premises deployment, yet no significant degradation can be observed in relation to the performance of the Services under investigation. Another important contribution is the concept of Component Administration Networks, designed to monitor and enforce a set of replicas that deal with storing system state data that can be used to recover in case of component or service failure. The integrated results of the thesis allow for the creation a free, decentralized, market for Cloud Applications to be deployed on different types of infrastructure. The resources are managed efficiently, according to high level business metrics, and the fault tolerance of Applications is enforced.