Tailscale Traces Database Corruption to 16y/o SQLite WAL-Reset Bug

Tailscale experienced months of service instability caused by a 16-year-old bug in SQLite's Write-Ahead Logging (WAL) reset functionality that corrupted their databases. After intensive forensic investigation uncovering 19 separate corruption instances over six months, the company identified and fixed the bug, and helped uncover this long-standing issue in SQLite's core. Tailscale uses SQLite as its primary database across internal coordination servers and maintains backups to S3, making this rare database corruption particularly concerning despite the company's single-writer design approach.