Practice of Cloud System Administration, The: DevOps and SRE Practices for Web Services, Volume 2

Chapter 18. Capacity Planning

Plans are nothing, planning is everything.

—Philip Kotler

Capacity planning means ensuring that there will be enough resources when they are needed. Optimally this is done such that the system is neither under capacity nor over capacity. Resources include CPUs, memory, storage, server instances, network bandwidth, switch ports, console connections, power, cooling, datacenter space, and any other infrastructure components that are required to run a service.

There are two major objectives of capacity planning. First, we want to prevent service interruptions due to lack of capacity. Second, we want to preserve capital investment by adding only the capacity required at any given time. Good capacity planning provides ...