ASHRAE Journal - August 2013 - 88

Column Data Centers

Donald L. Beaty

Computing Defines Centers
By DonalD l. Beaty, P.e., Fellow asHrae

Not all data centers are the same, and this can be largely attributed to differences in computing. Many different industries and operations require data
centers, and each has its own needs, which leads to lots of variability. For
example, data centers that support Internet service providers are significantly
different from those serving high frequency trading stock exchanges.
This column provides some insight into how software defines the data center and how data centers
vary because of this. A data center design begins with
software, then the hardware chassis to support the software, then the cabinets or racks, followed by the data
center infrastructure to support the cabinets or rack
space, power, and cooling needs. In general, however,
ASHRAE’s Thermal Guidelines for Data Processing Environments
apply to all types of electronic equipment and all types of
data centers.

could be spread across a number of specialized devices
in the data center. General purpose servers were still
widely used, but the software installed turned these
into network firewalls, web servers, application servers, caching servers, database servers, voice services,
etc.
Storage and networking changed dramatically during this period as well, as system administrators/technicians found that common Ethernet networks had
enough capability to handle not only server-to-server
communications, but server-to-storage devices. This
Types of Computing
allows the creation of new specialized devices called
Ever since the mid-1980s, the predominant style of
storage servers and network servers. Storage servers
computing has consisted of large, centralized computallowed many compute-servers to access centralized,
ers and a collection of smaller end user computing
virtualized caches of disk, making administration and
devices. The original “client-server” applications had
capital use easier than having storage dedicated to each
logic split between a program that ran on large, profescompute server.
sionally maintained computers, and a smaller client
Networking devices changed too, moving from devices
application that handled customized configuration, local that had hard wired connections to ones that were
display processing, and some local processing of data.
driven by software and virtualization. The newer breed
Since program logic was split between server and client, of devices allowed technicians to physically wire a single
upgrades between the server and the client needed to be time, and then virtually reconfigure the connections
coordinated, making even minor changes difficult and
between computers, storage servers, and other infraexpensive.
structure using software.
In the 1990s, this model of computing was enhanced
Today, data centers are full of a combination of
by the advent of the World Wide Web and Internet
compute-servers, storage servers, and networking
browsers. Browsers were relatively simple programs,
devices in varying proportions. Some data centers,
and use of HyperText Markup Language (HTML), and
described later, also have specialized devices for
downloadable programming languages like Java and
graphic processing and security. The highest perforJavascript, led to all the logic shifting towards the cenmance requirements sometimes lead to the instaltralized servers.
lation of customized hardware solutions, but most
Then servers needed to be more flexible, adaptable,
often these devices are created from general purpose
and generally smaller, since pieces of the program logic computer hardware with one or two special purpose
88

ASHRAE JouRnAl

ashrae.org

Au g ust 2013

ASHRAE Journal - August 2013

Table of Contents for the Digital Edition of ASHRAE Journal - August 2013