Page 107 - Cloud Essentials

4. The results of these steps must be regularly evaluated, and this

evaluation must be acted upon. Items that must be periodically
evaluated include the following:
Cloud solutions must be monitored to determine their efficiency and
effectiveness.
Cloud adoption usually means that IT services are coupled with specific
business processes.
The cloud benefits must outweigh the cloud-related risks and

expenditures.

CERTIFICATION OBJECTIVE 4.04

Migrating Applications to the Cloud

The choices available when you move to the cloud mirror the choices
available in a cloud exit strategy of the sort we described earlier. Here are
a few examples of the range available:

Move the entire application stack to an IaaS provider, replacing the

existing servers.
Replace the application by a functionally equivalent application in the
cloud, which is a SaaS approach.

Adopt an intermediate median strategy, where the application is broken
into pieces, and each of these pieces is separately considered for
migration to a cloud. This creates interfaces between application
components that could be reused as PaaS components.

Each alternative has to be weighed against the business reason for cloud
adoption. For example, a cost reduction goal might favor a SaaS approach,

whereas a scalability goal is more likely to lead to a PaaS approach,
because the breakup will enable more scalability in each component.

CERTIFICATION SUMMARY

Choosing the right cloud solution for a specific business can be difficult.
Initial cloud testing should be done with low-risk applications that are not
critical to business functions; this is usually a SaaS offering such as word
processing. Cloud elasticity makes applications with unpredictable peak
loads excellent cloud candidates.

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