Description

The federated cloud is a system for sharing, migrating and aggregating services among divergent, heterogeneous cloud providers through the centralized control mechanism. Horizontal federation and vertical federation are two models of federated cloud. Service providers at the same layer form horizontal federation and service providers at different layers form vertical federation. Federated cloud sub divided into centralized (agent based service selection) and peer-to-peer (peer selects services). In centralized federation, service providers communicate and share services through a centralized agent. In peer-to-peer federation, service providers interacts each other through common communication mechanism and no centralized agent required.

Multicloud is a heterogeneous architecture that aggregates services from multiple clouds. In a multi-cloud, customers are gathering services from multiple service providers and create as a single composite service. Customers are responsible for gathering and controlling services. Multicloud is classified further into services and libraries.

Federated cloud has gained huge popularity among the cloud service providers as it facilitates service sharing ability to meet dynamic demand. Cloud federation interconnects service providers and aggregates unused services of the federation to meet dynamic demand. The small and medium-sized service providers join the federation to meet dynamic service demand. Bartering is a technique used to exchange services for other services without monetary benefits. Cloud federation provides a monetary based solution to the problem mentioned above. However, monetary based service exchange is frightening for the service providers with limited capital investment.