Eric Sammer is currently a Principal Solution Architect at Cloudera where he helps customers plan, deploy, develop for, and use Hadoop and the related projects at scale. His background is in the development and operations of distributed, highly concurrent, data ingest and processing systems. He's been involved in the open source community and has contributed to a large number of projects over the last decade.
"Overall, this is an excellent book to have on hand when planning, installing, and configuring a Hadoop file system and cluster. This book is useful even if you are not building from one of the two major distributions of Hadoop (Apache and Cloudera). Note, however, that this book does not cover using the Hadoop file system and cluster."
--W. E. Mihalo, Computing Reviews
"If you are concerned or interested in learning how to setup, run, maintain and operate Hadoop in a real, live setting I cannot think of a better book than this one."
--Edmon Begoli, Toolbox.com