Page 47 - Cloud computing: From paradigm to operation

Framework and requirements for cloud computing 1

I.8 Inter-cloud computing use case

Use case

Name Inter-cloud computing use case for federation
Abstract CSPs federate to provide a service to the CSC
Roles CSC, CSP

Figure

Pre-conditions – CSPs federate with each other by establishing a trust relationship and policy settlement.
(optional) – A CSC uses a service provided by one of the federated CSPs.
– Case-A: The CSP that offers the service to the CSC is going to spend all resources due to
overload, or has lost the resources due to disaster.
– Case-B: The CSC changes its environment (e.g., location) and reaches the CSP from a
place which is further away than before.
Post-conditions – Case-A: The CSP ensures that its services continue to be offered by the support of other
(optional) federated CSPs, even when performance or availability of the service may be degraded
due to CSP's resource problems (e.g., overload or disaster).
– Case-B: Another CSP in the federation, on behalf of the CSP which has offered the
service to the CSC, provides a new appropriate service environment to the CSC to
compensate for possible degradation, even when performance or availability of the
service may be degraded due to a CSC's environmental change (e.g., location changes).

Requirements – On-demand assignment of cloud resource among CSPs
– Resource and load distribution
– Large-scale migration
– User environment adaptation

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