One man's perspective on ideas may be useful as we think about clusters and the process of creating them:
"Truth happens to an idea. It becomes true, is made true by events. Its veracity is in fact an event, a process: the process namely of its verifying itself, its veri-fication. Its validity is the process of its valid-ation."
—William James, A Pluralistic Universe , Lecture 8
Whether or not you agree with this sentiment, the quotation provides a useful perspective on the process of taking an idea and making it real. We're taking a technology—the Linux cluster—and determining the steps needed to make a valid solution from the abstract idea or architecture. The better we become at validating the steps and verifying the results, the better we'll become at building clusters. While this process needs to be rooted in reality, a rigid process leaves no room for adapting to changes in customer requirements, new components, or new construction techniques—we need to be as flexible as our customers demand.
In our three-article series on building Linux clusters, we've addressed the why, what, and how of creating this type of solution. This series is intended only as an introduction to the topic, and there has not been space enough to cover cluster building to any great depth. Hopefully, however, now that the tips of the icebergs are visible, you can put on your dry suit,* jump out of the helicopter, and explore the depths of the subject on your own.