Aggregation of cloud providers: A review of opportunities and challenges

A single cloud provider alone is not able to satisfy the increasing demand for its services as the number of online users and services deployed by organizations grow exponentially. To achieve the promises of cloud computing, the necessity of aggregating different cloud provider into a single framework emerges. This concept overcomes the limitations of interoperability, portability, vendor lock in problem, scalability and elasticity of contemporary cloud computing. Collaborating with different cloud providers is not an easy task because each cloud provider has different kinds of architecture, virtualization technology, service level agreement, enterprise solution and interface for accessing services. This scenario is identified by many synonyms in the literature such as cloud federation, Inter-cloud, Multi-Cloud etc. This paper discusses various driving forces and advantages that attract researchers towards it. Further, this paper concentrates on exploring related work done in addressing different issues and finding gaps that will create opportunities for further research and development. This work will tend to emerge as a step towards the next-generation enterprise solution.