Programmer Musings

Review of Release It!

Release It!
Michael T. Nygard
Pragmatic Bookshelf, 2007

I've had this book on my shelf for a few years, and finally got some time to start reading it. I should not have waited.

Nygard takes the position that the life of a piece of software actually only begins when it is released. He spends a lot of time on the way things go wrong in production that you won't see in a development environment. Anyone who has ever survived a push to release and been surprised that there's no time to relax will really appreciate this book.

The book contains a large number of war stories showing things going wrong in real projects. Some of the failures are obvious, others are surprising. Nygard distills these failures down to some anti-patterns that can cause problems with stability or capacity. Then, he provides design patterns that can mitigate or eliminate some of the problems in release.

Some of these design patterns seem obvious: Use Timeouts or Pool Connections. Others are less familiar: Circuit Breaker or Bulkheads. Like the patterns from the Gang of Four book, a large part of the benefit of the patterns is having common names and descriptions of the patterns. This applies whether you have been using them for years or have seen them for the first time. If you are seeing them for the first time, his descriptions are good enough that you should quickly understand the pattern.

The section on general design principles is very effective, but the part that most developers really need to read is the section on Operations. Too often, those of us developing software forget what the operations people need from the software. When we think of them at all, we try to provide a nice interface for a few admin tasks. Nygard points out that a pretty interface is nowhere near as useful as a scripting or command line interface. He also describes examples of how this kind of approach actually helps operations.

Overall, this is a really great book for anyone that is releasing software that must run in a production environment. If you fall in this camp, you should get the book and read it before your next project.