NetNORAD: Troubleshooting networks via end-to-end probing

What this post added

Introduced NetNORAD, a system for end-to-end network probing using UDP probes to measure packet loss and latency, independent of device polling. Developed pinger and responder processes for servers, and the fbtracert utility for path analysis. Implemented data processing pipeline using Scribe and Scuba for real-time logging and analysis, with an alarming process to detect and alert on network failures within 20-30 seconds. Introduced fault isolation principles based on proximity tagging (DC, Region, Global) and downstream suppression, complemented by fbtracert for more granular path analysis. Open-sourced key components (UdpPinger and fbtracert).