Hadoop: The Definitive Guide

http://www.lexemetech.com/2008/09/hadoop-definitive-guide.html

Google App Engine – performance under high load

http://service-architecture.blogspot.com/2008/10/google-app-engine-how-many-megas-in.html
and
http://service-architecture.blogspot.com/2008/10/killing-cloud-mandelmap.html