Tools

Infrastructure Sizing Calculator

Nodes needed for peak load at a sane utilisation target, and with a whole failure domain lost.

Infrastructure Sizing Calculator

Sizes for peak load at a sane utilisation target, and for losing an entire failure domain. Both are routinely left out, which is why capacity plans look fine until a zone goes down.

Average requests per second

Peak multiplier over average

CPU milliseconds per request

Cores per node

Target CPU utilisation at peak (%)

Queueing delay rises sharply near saturation. Sizing to 100% gives you a system that is adequate on paper and unusably slow.

Failure domains, such as availability zones