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automation, high levels of use of the shared resources, virtualisation,
flexibility, etc. have a positive effect on the bottom line.
At this point it is important to point out once more that the reference to
these operating models does not constitute a definition in a technical or
legal sense and that it cannot be applied consistently for the Cloud service
on offer. The "privateness" included in the Cloud offering may not fulfill the
Cloud user's requirements, and it is recommended to check these services
for compliance. The chapters on the legal dimension of Cloud computing will
take a more detailed look at this aspect.
Hybrid Cloud
Hybrid Clouds are a combination of Public Cloud, Private Cloud services
provided by legacy IT systems. The Public and Private Cloud servers are
connected to the respective providers via standardised protocols and
interfaces. This mix of integrated services reflects the enterprise's individual
IT requirements. Depending on the security requirements, applications
reside inside or outside of the firewall. This makes it possible to achieve
security goals while at the same time leveraging savings and scaling effects.
Most analysts anticipate that Hybrid Cloud deployments will dominate the
market in future to allow enterprise to procure services in a modular way
from both worlds, the Private Cloud or the Public Cloud, depending on
priority and sensitivity of the requirements. The decisions will be based on
business needs, company policies, IT requirements, and of course the
resulting costs.
Typically, implementing a model like this will require a very careful design,
and it will be generally much more complex than one of the non‐hybrid
approaches.
Two factors will be critical for the success of Hybrid Cloud solutions:
Transparent integration of various service components, so that
consumers are unaware of the origin or the transition points
between the individual modules and unable to identify their sources.
Complete integration of the individual components to create a
turnkey hybrid Cloud also means being able to manage the solution
in a pervasive and consistent way. In an ideal case this means that,
independent of the role the individual components play, or where
they are procured and administration and monitoring is identical. For
example, business process control components, or access privilege
management and monitoring can be used in the same way, and
