Cloud Computing builds on the latest achievements of diverse research areas, such as Grid Computing, Service-oriented computing, business processes and virtualization. In this paper, we reveal open research issues by envisaging a federated cloud that aggregates capabilities of various IaaS cloud providers. We propose a Federated Cloud Management architecture that acts as an entry point to cloud federations and incorporates the concepts of metabrokering, cloud brokering and on-demand service deployment. The meta-brokering component provides transparent service execution for the users by allowing the system to interconnect the various cloud broker solutions available in the system. Cloud brokers manage the number and the location of the utilized virtual machines for the received service requests. In order to fast track the virtual machine instantiation, our architecture uses the automatic service deployment component that is capable of optimizing service delivery by encapsulating services as virtual appliances in order to allow their decomposition and replication among the various IaaS cloud infrastructures. Our solution is able to cope with highly dynamic service executions by federating heterogeneous cloud infrastructures in a transparent and autonomous manner. |