A deeply buried 16-year-old bug in SQLite's write-ahead log has been identified as the cause of outages experienced by Tailscale users last year. The bug, known as the WAL-Reset bug, is a rare data race in the SQLite source code.
Key Insights
The bug was discovered after a six-month investigation with the help of SQLite maintainers. The issue is extremely unlikely to occur in ordinary use, but can have serious consequences. Fortunately, the bug has now been fixed, and Tailscale users can expect a more stable experience.










