Page 306 - Cloud computing: From paradigm to operation

1 Framework and requirements for cloud computing

Appendix I

Use cases from the inter-cloud perspective
(This appendix does not form an integral part of this Recommendation.)

This appendix describes use cases in which multiple cloud computing systems interact with each other to
satisfy the specified requirements and how cloud systems work in each use case.

I.1 SLA mapping in intermediary pattern

This use case illustrates the SLA mapping between the primary CSP in inter-cloud intermediary pattern (called
CSP-Intermediary) and other secondary CSPs.

Multiple CSPs contribute to, or impact concurrently, the SLA between the CSP-Intermediary and the CSC
when an orchestrated service is provided.
Table I.1 shows SLA mapping in an inter-cloud intermediary pattern.

Table I.1 – SLA mapping in an inter-cloud intermediary pattern

Use case
Use case title SLA mapping in an inter-cloud intermediary pattern
Relevant roles CSC and CSP

Use case description – The primary CSP in an inter-cloud intermediary pattern (CSP-
Intermediary) is the contact point for CSC and there is SLA (SLA0)
between them.
– The CSP-Intermediary integrates services from multiple CSPs, for
instance, storage service from CSP-1 and computing service from CSP-2.
There are business-to-business (B2B) level SLAs between CSP-
Intermediary and CSP-1, CSP-2 respectively (SLA1, SLA2).
– For the CSP-Intermediary, in order to guarantee SLA0 for CSC, it is
necessary to map SLA0 to SLA1 and SLA2, because SLA0 is actually
implemented by SLA1 and SLA2.
Information flow SLA mapping may be performed via explicit information exchange or off-line
negotiation.

High-level figure describing the CSP-1 with
SLA 1 storage service
use case
SLA 0 CSP
CSC (Intermediary)
CSP- 2 with
SLA 2 computing service
Y.3511(14)_FI.Tab1
Derived requirements for cloud – The capability to support SLA negotiation between CSP-Intermediary
capability and other CSPs is recommended.
– The capability to support coordination of the SLAs from multiple CSPs
(which is related to a business decision) is recommended.

I.2 Performance guarantee against an abrupt increase in load (offloading)

Table I.2 shows an inter-cloud use case where performance is guaranteed in case of an abrupt increase in
load.

NOTE – The following legend applies to the Figures in Tables I.2 to I.5:

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