Blue Light Special: Ensuring fast global configuration changes

CloudFlare, a global network of servers, provides fast configuration changes for its customers' websites and DNS systems. The company constantly updates configurations, with an average rate of 40 changes per second. To ensure quick propagation times across data centers, CloudFlare monitors metrics and uses a custom alert system that triggers a blue rotating "police light" when propagation time exceeds a threshold. This helps the team to quickly identify issues and take necessary actions.