Site Reliability Engineering, 2nd Edition

Chapter 13. Testing

By Aman Shaikh, Elliot Williams, Forrest Seiwald, Joanna W., Joon Lee, Niall Murphy, Nicholas Crespi, Thomas Hubschman, and Yuri Grinshteyn

with Alex Perry, Max Luebbe, and Carmela Quinito

A Note for Early Release Readers

With Early Release ebooks, you get books in their earliest form—the author’s raw and unedited content as they write—so you can take advantage of these technologies long before the official release of these titles.

This will be the 14th chapter of the final book. Please note that the GitHub repo will be made active later on.

If you’d like to be actively involved in reviewing and commenting on this draft, please reach out to the editor at [e-mail].

In 1882, Benjamin Brewster wrote in a Yale student magazine “In theory, theory and practice are the same; in practice, they are not.” This is as good a one-sentence summary of why testing exists as there is. It is also a clue as to why testing is more important than ever in today’s era of massive distributed systems, complex production environments, and a rapidly growing deployment of AI authored or AI related software, none of which would be at all possible without it.

You’ve probably mostly encountered testing in the context of the software development lifecycle (SDLC) where it’s the phase before deployment and, as a result, before the new software gets put in front of users. This traditional role of testing is probably still the most common way it’s used today, though that’s changing ...