The technical wizardry behind Google's successful search engine may come down to a blindingly obvious insight: PCs crash.
On Wednesday, Urs Hoelzle, a vice president of engineering and of operations at the search giant, shed some light on how Google's data centers operate.
Bottom line: According to Hoelzle, Google has inexpensively built out its computing infrastructure by using thousands of "commodity" servers, instead of fewer high-end, and high-priced, machines.
The trick is to make these racks of hardware work together and to ensure that the failure of one machine doesn't derail an operation.
The way Google has been able to build out its computing infrastructure for millions, rather than tens of millions, of dollars is by buying relatively cheap machines.
Looking at hardware costs, company engineers saw that purchasing a few high-end servers, with eight or more powerful processors, costs significantly more than dozens of simpler "commodity" servers.
The trick is to make these racks of hardware operate in tandem and to ensure that the failure of one machine does not derail an operation, such as returning a search query or serving up an ad.
The company wrote its own file system, called Google File System, which is optimized for handling large, 64 megabyte blocks of data.
Significantly, the file system was designed to assume that a failure, such as a failed disk or unplugged network cable, can happen at any time.
Google's programming tool, called MapReduce, which automates the task of recovering a program in case of a failure, is critical to keeping the company's costs down.
In a follow-up interview with CNET News.com, Hoelzle said the cost of power is another important factor in Google's data center designs.