Cloud Computing
Cloud computing is the provision of dynamically scalable
and often virtualized resources as a services over the
internet Users need not have knowledge of, expertise in, or control
over the technology infrastructure in the "cloud" that supports them.
Cloud computing represents a major change in how we store information and run
applications. Instead of hosting apps and data on an individual desktop
computer, everything is hosted in the "cloud"—an assemblage
of computers and servers accessed via the Internet.
Cloud computing exhibits the following key characteristics:
1. Agility improves with users'
ability to re-provision technological infrastructure resources.
2. Multi tenancy enables
sharing of resources and costs across a large pool of users thus allowing for:
3. Utilization
and efficiency improvements for systems that are often only 10–20%
utilized.
4. Reliability is
improved if multiple redundant sites are used, which makes well-designed cloud
computing suitable for business continuity and disaster
recovery.
5. Performance is monitored and
consistent and loosely coupled architectures are constructed using web services as
the system interface.
6. Security could
improve due to centralization of data, increased security-focused resources,
etc., but concerns can persist about loss of control over certain sensitive
data, and the lack of security for stored kernels. Security is often as good as
or better than other traditional systems, in part because providers are able to
devote resources to solving security issues that many customers cannot afford.
However, the complexity of security is greatly increased when data is
distributed over a wider area or greater number of devices and in multi-tenant
systems that are being shared by unrelated users. In addition, user access to
security audit logs may
be difficult or impossible. Private cloud installations are in part motivated
by users' desire to retain control over the infrastructure and avoid losing
control of information security.
7. Maintenance of cloud computing
applications is easier, because they do not need to be installed on each user's
computer and can be accessed from different places.
