Page 312 - Cloud computing: From paradigm to operation

1 Framework and requirements for cloud computing

Table I.5 – Inter-cloud use case: Service continuity

Use case
Use case title Inter-cloud use case: Service continuity
Relevant roles CSP and CSC
Use case description – The cloud service offering continues through the collaboration with other
CSPs, even when the original CSP terminates its business.
– Available resources in the CSPs other than the service-terminating CSP are
discovered and reserved in advance.
– Network connections among the interworking CSPs are established or
reconfigured. Then service-related data including user identifier (ID), user
data and application data are transferred from the original CSP to the new
CSPs.
– Access from CSCs is appropriately changed to the interworking CSPs so that
the same service is continuously offered.
– If the capabilities (VM and applications) at the original CSP migrate to other
CSPs, the CSC, who keeps the same user ID, can continuously access the
service at the same level of performance as before.
Information flow – The relevant CSPs are supposed to join a common trusted alliance in
advance and set up the service level agreements (SLAs).
– The terminating CSP inquires about the resource availability of other CSPs
in the alliance and requests a reservation of the available resources to
continue the services.
– The cloud resource management (e.g., CRUD: create, read, update and
delete) are operated across multiple CSPs. The management is to enable
leasing of the cloud resources from different CSPs in the federation.
High-level figure describing the Pre-processes
• CSPs form a group with service level agreement (i.e., policy negotiation).
use case • P-CSP replicates its data to other S-CSPs in advance.
3. The P-CSP chooses S-CSPs and reserves the resources.
2. The P-CSP initiates 3a. When some CSCs are in service, the P-CSP performs
service closure. migration to continue the service to the CSCs.
3b. When no CSC is in service, the S-CSP invokes
application to offer the same service.
1. A CSC accesses Primary-
P-CSP services. CSP n
o
n
CSC S-CSP
Secondary- S-CSP
CSP Group
4. P-CSP changes the
CSC access to the S-CSP.
NOTE – When all services and their users are moved to other S-CSPs, P-CSP will close the service.
Y.3511(14)_FI.Tab5
Derived requirements for cloud The system is required to support:
capability – Policy negotiation including SLA management among the multiple CSPs
within a pre-established group (federation);
– Discovery, reservation, use and release of the cloud resources in a dynamic
manner (i.e., not relying on the pre-configuration) across the multiple CSPs
within the federation;
– Capability migration (e.g., VM and applications) among multiple CSPs within
the federation;
– Alteration (i.e., switchover) of the CSC access, in a dynamic manner (i.e., not
relying on the pre-configuration), from one CSP to another CSP within the
federation;
– Exchange of authentication information about CSC (user/enterprise)
authentication status among the multiple CSPs within the federation.

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