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Chapter 1  Internet Era: E-Commerce 23
The capability to match resource requests to available resources in accor-
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dance to policies and business objectives
The ability to reject resource requests in a graceful manner based on
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policy exceptions
The capability to predict and plan resource utilization
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Policies to drive the resource sharing behavior
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Optimization of resource allocation based on usage and Service Level
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Agreements (SLA)
Physical Abstraction
There should be no dependencies between the application and an infrastructure
implementation that would prevent relocation of the application to other loca-
tions in the cloud. This abstraction is critical for resources such as IP addresses,
data sources, and file systems. Physical abstraction is accomplished by satisfying
the following additional requirements:
Virtualization of the hardware.
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Designing applications with no local dependencies (local hard disk, specific
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hardware, hardwired resources such as IP addresses, and so on).
Late binding between the services and their physical realization. That is,
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all such bindings are performed during the runtime of the system.
Utility Model
One of the characteristics of the utility model is a pay-as-you-go chargeback.
While this might not be a goal at your organization, accounting of usage based
on actual allocation is an incentive to keep the resources low in the beginning
and to optimize them over time. This model will allow your e-commerce cloud
to scale gracefully.
Self Service
One of the key goals of cloud computing is to enable the fastest time-to-market
(TTM) for the features of your e-commerce site. Achieving this goal would
depend on:
Simplifying and automating the processes.
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Delegating resource management to application owners (or domain own-
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ers) to enable them to manage the capacity of their resources within pre-
defined limits.
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