I end up doing a lot of debugging, in fact every single day I'm debugging something. Some days it is software and scripts that I'm using for my PhD research, some days it is failed laboratory equipment, and some days it's working the problems out of a new instrument design. Growing up working on mechanical things really helped me develop a knack for isolating problems, but this is not knowledge that everyone has the occasion to develop. I'm always looking for ways to help people learn good debugging techniques. There's nothing like discovering, tracking down, and fixing a bug in something. Also, the more good debuggers there are in the world, the fewer hours are waisted fruitlessly guessing at problems.
I'd heard about a debugging book that was supposed to be good for any level of debugger, from engineer to manager to homeowner. I was a little suspicious since the is such a wide audience, but I found that my library had the book and checked it out; it is "Debugging: The 9 Indispensable Rules for Finding Even the Most Elusive Software and Hardware Problems" by David Agans. The book sat on my shelf for a few months while I was "too busy" to read it. Finally, I decided to tackle a chapter a day. The chapters are short and I can handle two weeks of following the book. Each morning when I got to work, I read the chapter for that day. One weekend I read an extra chapter or two because they were enjoyable.
I'm not going to ruin the book, but I am going to tell you the 9 rules (it's okay, they are also available in poster form on the book website).
- Understand the System
- Make It Fail
- Quit Thinking and Look
- Divide and Conquer
- Change One Thing at a Time
- Keep an Audit Trail
- Check the Plug
- Get a Fresh View
- If You Didn't Fix It, It Ain't Fixed
They seem simple, but think of the times you've tried to fix something and skipped around because you thought you knew better to have it come back to sting you. If you've done a lot of debugging, you can already see the value of this book.
The book contains a lot of "war stories" that tell tales of when a rule or several rules were the key in a debugging problem. My personal favorite was the story about a video conferencing system that seemed to randomly crash. Turns out the compression of the video had problems with certain patterns and when the author wore a plaid shirt to work and would test the system, it failed. He ended up sending photocopies of his shirt to the manufacturer of the chip. Fun stories like that made the book fun to read and show how you have to pay attention to everything when debugging.
The book has a slight hardware leaning, but has examples of software, hardware, and home appliances. I think that all experimentalists or engineers should read this early on in their education. It'll save hours of time and make you seem like a bug whisperer. Managers can learn from this too and see the need to provide proper time, tools, and support to engineering.
If you like the blog, you'll probably like this book or know someone that needs it for Christmas. I am not being paid to write this, I don't know the author or publisher, but wanted to share this find with the blog audience. Enjoy and leave any comments about resources or your own debugging issues!
