This chapter seeks to help an SA [system administrator] decide how much centralization is appropriate, for a particular site or service, and how to transition between more and less centralization.
Centralization means having one focus of control. One might have two DNS servers in every department of a company, but they all might be controlled by a single entity. Alternatively, decentralized systems distribute control to many parts. In our DNS example, each of those departments might maintain and control its own DNS server, being responsible for maintaining the skill set to stay on top of the technology as it changes, to architect the systems as it sees fit, and to monitor the service. Centralization refers to nontechnical control also. Companies can structure IT in a centralized or decentralized manner.
Decentralization means breaking away from the prevailing hegemony, revolting against the frustrating bureaucratic ways of old. Traditionally, it means someone has become so frustrated with a centralized service that "do it yourself" has the potential of being better. In the modern environment decentralization is often a deliberate response to the faster pace of business and to customer expectations of increased autonomy.
Centralization means pulling groups together to create order and enforce process. It is cooperation for the greater good. It is a leveling process. It seeks to remove the frustrating waste of money on duplicate systems, extra work, and manual processes. New technology paradigms often bring opportunities for centralization. For example, although it may make sense for each department to have slightly different processes for handling paper forms, no one department could fund building a pervasive web-based forms system. Therefore, a disruptive technology, such as the web, creates an opportunity to replace many old systems with a single, more efficient, centralized system. Conversely, standards-based web technology can enable a high degree of local autonomy under the aegis of a centralized system, such as delegated administration.
Network centralization and decentralization
Candidates for centralization
Candidates for decentralization
Reproduced from the Addison-Wesley Professional book The Practice of System and Network Administration, 2nd Edition, by Thomas A. Limoncelli, Christina J. Hogan and Strata R. Chalup. ISBN 978-0321492661. Copyright 2007, Addison-Wesley Professional. Reproduced by permission of Pearson Education Inc., 800 East 96th St., Indianapolis, IN 46240. Written permission from Pearson Education Inc. is required for all other uses.