# Over four billion Web pages, each an average of 10KB, all fully indexed.
# Up to 2,000 PCs in a cluster.
# Over 30 clusters.
# 104 interface languages including Klingon and Tagalog.
# One petabyte of data in a cluster -- so much that hard disk error rates of 10-15 begin to be a real issue.
# Sustained transfer rates of 2Gbps in a cluster.
# An expectation that two machines will fail every day in each of the larger clusters.
# No complete system failure since February 2000.
And it is all hidden behind a deceptively simple, white, Web page that contains a single one-line text box and a button that says Google Search.
http://www.zdnet.com.au/insight/software/0,39023769,39168647,00.htm