Page 259 - How Cloud Computing Is Transforming Business and Why You Cant Afford to Be Left Behind

GL OS SARY

Infrastructure as a service (IaaS): One of the major forms of
cloud computing. An online service, such as Amazon Web Serv-
ices Elastic Cloud Compute (EC2), provides raw compute
power on a per hour basis.

Internet: The worldwide network that grew out of the DARPA
project to establish a communications network that could suf-
fer a failure at any given point and continue to function. It’s

based on the Transmission Control Protocol/Internet Proto-
col (TCP/IP), which can route around a point of failure.

Loosely coupled: A method of computing over a shared net-
work where two systems don’t need to know very much about
each other in order to exchange vital information.

Mainframe: A large, general-purpose computer; the first was
the IBM 360 in 1964, and a succession of generations has fol-
lowed, including the zSeries from IBM that is available today.

Maintenance: In data center operations, the effort required to
maintain the production systems necessary to the business and
keep them running smoothly. Maintenance tends to take up

three-quarters of the typical information technology depart-
ment budget. New initiatives vie for resources with mainte-
nance.

MapReduce: A combined software function, running on a large
server cluster, that pulls data off a set of disks simultaneously,
maps it to the cluster processor that is closest to it in 64- or
128-megabyte chunks, then “reduces” or performs a sorting
or filtering process on the data. MapReduce, for example, can
determine how many times a keyword occurs in the chunk, a

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