This summary of network centralization and network decentralization draws together the tips and best practices outlined in five previous sections:
Introduction to network centralization/decentralization, the basics of network centralization/decentralization, candidates for centralization, candidates for decentralization and case studies in centralization/decentralization. Re-read those earlier sections to help you complete the exercises below.
Centralization and decentralization are complicated topics. Neither is always
the right solution. Technical issues, such as server administration, as well as
nontechnical issues, such as organizational structure, can be centralized or
decentralized.
Both topics are about making changes. When making such pervasive
changes, we recommend that you consider these guiding principles: know
what specific problem you are solving; understand your motivation for making
the change; centralize as much as makes sense for today; recognize that
as in rolling out any new service, it requires careful planning; and, most
important, listen to the customers.
It is useful to learn from other people's experiences. The USENIX LISA
conference has published many case studies (Epp and Baines 1992;
Ondishko 1989; Schafer 1992b; and Schwartz, Cottrell, and Dart 1994).
Harlander (1994) and Miller and Morris (1996) describe useful tools and the
lessons learned from using them.
Centralizing purchasing can be an excellent way to control costs, and our
example showed that it can be done not by preventing people from getting
what they want, but by helping them make purchases in a more cost-effective
manner.
We ended with a discussion of outsourcing. Outsourcing can be a major
force for centralization and will be a large part of system administration for
a very long time, even under different names.
Centralization Rules of Thumb Every site is different, but we have
found that, as an informal rule of thumb, centralization of the following
services is preferred once a company grows large enough to have multiple
divisions:
Exercises
- How centralized or decentralized is your current environment? Give
examples.
- Give an example of a service or an aspect of your organization that
should be centralized.
- Give an example of a service or an aspect of your organization that
should be decentralized.
- We describe decentralizing email servers to achieve
better reliability. How would you construct a similar architecture for
print servers?
- Describe a small centralization project that would improve your current
system.
- Share your favorite outsourcing horror story.
Network centralization and decentralization
Introduction
The basics
Candidates for centralization
Candidates for decentralization
The icing
Conclusion/exercises
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.
