This book is recently published, April 2015, and it covers Nagios, Ganglia, Hadoop monitoring and monitoring best practices.
The first part is rightfully devoted to Nagios. Nagios is covered quite in depth: install, verification and configuration. It gives you the right balance: it does not say everything that there is in a Nagios manual, but tells you sufficient information to install Nagios and prepare it to monitor specific Hadoop daemons, ports, and hardware.
The same goes for Ganglia: it is covered in sufficient detail for one to be able to install and run, with enough attention to Hadoop specifics.
What I did not find in the book, and what could be useful... to read further