Site Reliability Engineering, 2nd Edition

Chapter 14. Capacity Planning

Andy Gordon, Chris Kirby, D. Hixson, Emily Tocin, Frank Szczerba, Jessica Mc Carthy, Katie Poskaitis, Nick Soda, Rob Whitaker, Samantha Schaevitz, Sierra Ventuleth, Stephanie Yan, Thais Melo, and Thomas Voß

with 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 15th 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].

Capacity planning is the discipline of forecasting future demand and provisioning the supply to meet it. To scale infrastructure successfully, you must balance performance, cost, and reliability—all anchored by your core business goals.

Capacity planning heavily parallels the concept of error budgets. Just as 100% uptime is the wrong target for reliability, provisioning for every statistical edge case is the wrong target for capacity; you must make deliberate choices based on your explicit risk tolerance.

This chapter explains in detail how Google tackles operational and mid-term capacity planning. Balancing this complexity has never been more vital, especially as we scale to meet the explosive infrastructure demands generated by AI. In ...