Service Provisioning Definition, Topology, and Taxonomy

Cloud service provisioning is a manner of providing customers access to resources to complete the desired tasks required by the customer. The hardware, software, or computational tasks can be the form of provisioned resources. In topological perspective, service provisioning is divided into two parts: single cloud and intercloud. A single cloud computing data center is used by the client who brings several challenges. The unavailability of cloud service can leave thousands of customers relying solely on limited essential and paid resources. Grozev and Buyya introduce and present taxonomies of federated cloud architectures, mechanism of application brokering, and the current environments. Formally, intercloud computing is defined as in:

"a cloud model that, for the purpose of guaranteeing service quality, such as the performance and availability of each service, allows on-demand reassignment of resources and transfer of workload through an interworking of cloud systems of different cloud providers based on coordination of each consumer's requirements for service quality providers SLA and use of standard interfaces".

The state-of-the-art thematic taxonomy of service provisioning is presented by classifying several vital key issues for further discussion. Figure 1 shows the taxonomy of service provisioning selection, comprising approaches, objectives, requirements, metrics, techniques, services, and topologies. There are several approaches to service selection, including brokerage based, SLA matching, and policy based, heuristic, and holistic. The techniques involved in different service provisioning approaches include the genetic algorithm, game theory, and multicriteria decision-making. The main objectives are availability, scalability, comparison capability, and the CSP's compliance with the relevant regulations. In addition, the primary requirements include QoS, web services (WS), security aspects, pricing, and the elastic capability of the services. The essential metrics are divided into three broad aspects: storage, network, and computation. Provisioning is fundamentally based on three core service models: infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS). It may derive from a single cloud or within the multicloud via the interaction of several service providers.

Figure 1 Taxonomy of cloud service provisioning.


By combining cloud and internet of things, Salvatore Distefano et al. envision and propose a new concept "cloud of things" (CoT). They aggregated heterogeneous resources and tailored thing-like semantics by enabling things as a service. Moreover, they model the cloud service computing as a sensing and actuation as a service (SAaaS), thus provisioning services by the sensors and actuators. An architecture is designed for pervasive ICT structure generating the nearby environment data by sensors and actuators through cloud.