April, 2009
Reviewed by Scott Chapman
In the introduction the author says that this book is for absolutely everybody. In that regards the book is quite successful; while describing mainframes, some basic enterprise computing concepts are explained. The description of databases should give non-technical readers a good flavor for some of the complexities of ensuring database integrity. However, readers who are IT professionals (even if they are not mainframe literate) may find those parts somewhat tedious.
Unfortunately, the author doesn't always clarify that some of those IT concepts apply to enterprise computing in general-not just mainframes. For example, mainframes are a relatively small piece of most datacenters today. But while discussing the complexities of managing a datacenter, the author only briefly mentions that other platforms might also need a datacenter. At the end of that discussion, the author concludes, "It's all part of the fun of running a Mainframe." True, a mainframe needs a datacenter, but there are a lot of datacenters that don't have mainframes, too.
However, the author does include a lot of good details for IT folks. The author explains JES2, CICS, DB2, and IMS in enough detail to give non-mainframe people a good overview of these potentially mysterious subsystems. He also describes parallel sysplex and LPARs. Although tape and disk hardware of various generations is explained, there is curiously no overview of the different mainframe processors commonly used today and very few details about the processor hardware overall. A block diagram showing the processor books, power, and I/O cards might have been nice, especially if it was contrasted with other server technologies.
Some may find the glossary in Appendix 3 quite valuable. Non-mainframe IT folks who suddenly find themselves having to deal with a mainframe project may want to keep this book handy to help translate their co-workers' lingo. An index also bolsters the book's value as a reference tool.
Overall, the book provides a brief and easy-to-read overview of the core attributes of mainframe computing. While the book would be even more valuable to IT readers if it compared and contrasted mainframe computing with other more familiar computing technologies, it definitely explains mainframes in a way everybody can understand.