I. cloud, along with less secure public clouds based

I.    INTRODUCTION1 C  loud Computing is a technology for thedelivery of computing services that are hosted over theInternet. It is an area of great interest due to its many potential benefits as it provides self-service provisioning,elasticity, migration flexibility, and a low-cost with high performancescalable computing. Yet, cloud computing is a technology of a major  concern on the security aspects; and one ofthe top ten cited obstacles to the adoption of cloud computing is “DataConfidentiality and Auditability”. This cloud security concern limits its usagein certain applications or by certain organizations.of a major  concern on the security aspects; and one ofthe top ten cited obstacles to the adoption of cloud computing is “DataConfidentiality and Auditability”.  This cloud securityconcern limits its usage in certain applications or by certain organizations.

Otherorganizations consider partitioning their workload over a combination offederated clouds, that contains a secure internal private cloud, along withless secure public clouds based on a set of security requirements. Thisapproach of partitioning has the potential benefit of exploiting the strengthsof both types of clouds; the secure private and the less-secure public clouds.It can offer much higher performance with a lower cost and higher security bydeploying the sensitive applications on a private cloud and those applicationswithout security concerns on the external less-secure public clouds. Currently,applications are allocated to the cloud on an ad-hoc per-applicationbasis where an application is allocated entirely either on a private cloud or apublic one. This is not ideal as it lacks auditability and the quality ofextreme thoroughness during the process of allocation of the whole applicationbased on its overall sensitivity. That said, even raising the level ofsensitivity of a whole application unnecessarily and deploying it on a secureprivate cloud may lead to the overload of the finite resources of the privatecloud which results in having poor performance and potentially a negativeimpact on other applications.  Another approach ofpartitioning, alternative to the ad-hoc based partitioning, an approach thathas the potential benefit from partitioning an application over a set of cloudswhile still meeting its overall security requirements, that is the multi-levelsecurity model for partitioning workflows over federated clouds. This approachis based on the multi-level t takes an application that consists of a set ofdata and services connected in a workflow, and results in having a complete setof options of valid deployments over a set of clouds while meeting the securityrequirements of the application as specified by the organization.

And sincethis method results in having more than just one valid option for thepartitioning, this leads to the issue of how to choose the best option. Thissurvey describes the various ways of choosing partitioning with it’s costanalysis.       II.    federated cloud definitions and approachesA.    Definitions There has been a trend towards managing local data centersas private clouds, thus the application developers who decide to host theirsystem in the cloud face the issue of choosing the cloud to meet their requirementsin terms of price, reliability and security. Itbecomes more complicated when the application consists of number of distributedcomponents on different clouds, the idea of accessing different clouds leads tofederated clouds as federation gives the ability to distribute application on morethan one cloud platform. However, there is three terms used with the same meaning offederation.

Cloud federation Inter-cloud Multi-cloud  Where cloud federation implies the creation of agroup of providers that are collaborating to share their resources in order toimprove each other’s services. the essential points to be maintained in federationis that the providers should deploy the virtual application among federatedsites , in addition to guaranteeing that the application is location free so itcan immigrate partially or totally between sites. Simultaneously withmaintaining the security privacy and independence of the members in federation.

 So Cloud Federation can be defined as: A relationship between two or more independent homogeneous/heterogeneous cloud Platforms which establish a trusted federation agreement in order to benefit of a particular form of business advantage Union of Clouds a collaborative network of Clouds that facilitate resource sharing with different service layers or models in order to achieve increased dynamic scalability, and effective resource utilization while provisioning during amount of demand Meanwhile, Inter-cloud has been introduced by CiscoBernstein et al. According Vint Cerf, who is recognized as one of “the fathersof the Internet” … It’s time to start working on Inter-cloud standards and protocolsso your data doesn’t get trapped in one of the problems with cloud computing … Iaddition it was defined as A cloud model that is used to guarantee the servicequality (eg. The performance and d availability of each service) , so itreassign the resources and transfer the workloads through interworking of cloudsystems of different cloud providers based on coordination of each consumer’s requirementsfor services quality with each provider’s SLA and use of standard interfaces  While Multi-Cloud means use independent clouds by aclient or a service. Where, the responsibility of managing resources acrossmultiple clouds carried out by SPs (service provider) or end-users.

 Unlike a federation, a multi-cloud environment does notimply volunteer interconnection and sharing of providers? infrastructuresClients or their representatives are directly responsible for managing resourceprovisioning and scheduling. Hence, both federations and multi-clouds are typesof Inter-Clouds. However, some experts prefer to give different definitions tothese terms. Ellen Rubin, founder and VP of Products at CloudSwitch, . Definethe primary difference between the Inter-cloud and Federation is that theInter-cloud is based on standards and open interfaces, while federation uses aprovider version of the interfaces. B.

    Approaches  1)    Centralized Approach Thereis Single broker acts as third party where its main task to match between acloud the requiring and offering clouds. So it’s considered as the establisherof the federation.  2)    Decentralized Approach Theclouds take the charge id discovery, communication, matching and selection ofthe partner which fits their requirements. 3)    Hierarchal approach Itis consists of network of brokers.

Where, the cloud connected to broker whichis connected to another broker to match the requirements of the requiring andoffering cloud.