If you are working on distributed systems or data storage systems, then it is a must read book for you. To make the best use of the book, one will have to read it, re-read it and keep it at his desk to refer. It covers many topics which I use in my day to day work. Most of the books in this area are either too theoretical or focus on the details of one or few frameworks. In contrast, the book covers the basic concepts which makes the book really valuable.