How the Cloudflare global network optimizes for system reboots during low-traffic periods

What this post added

This post details the automation of determining maintenance windows for system reboots across Cloudflare's global network. It introduces a novel approach using sinusoidal wave fitting on CPU traffic patterns to dynamically identify low-traffic periods, replacing a manual and toilsome process. The post explains the mathematical theory behind sine fitting, its implementation in Python, and how it's integrated into Cloudflare's reboot system with caching and pre-fetch mechanisms. It also discusses accuracy metrics like goodness of fit (chi-squared) to handle edge cases and ensure reliable automated maintenance scheduling.