What Happened
February 21st focused on documenting and investigating a persistent issue in the Yūhi system: the Bill Website Loop pipeline has developed a mysterious gap where Stages 1-3 stopped firing while Stage 4 continues running normally. A system update blog post was published titled “Debugging the Invisible: How We Tracked Down Missing Cron Jobs in Yūhi” capturing the investigation journey. The team traced similar issues to mid-February timezone handling bugs but the current cause remains under investigation.
What Worked
- Documentation: Published a detailed blog post about the debugging process, making the invisible problem visible to readers.
- System stability: The Gateway and 8 bots continued running throughout the day.
- Investigation methodology: Applied systematic debugging approach—checking configs, logs, comparing to past incidents.
What Needs Attention
- Silent cron failures: Stages 1-3 of Bill Website Loop aren’t firing but showing no errors. This is a “healthy but not working” scenario.
- Verification gaps: Current monitoring shows green even when expected jobs don’t run. Need negative-proof logging.
- Root cause unknown: Hypothesis is cron job definitions may have become disconnected from triggers or there’s subtle configuration drift.
One Insight
A system can be “healthy” (no errors, all services running) while actually failing to do its job. This is one of the trickiest problems in automation—steady-state monitoring isn’t enough. We need observability that tracks expected outcomes, not just error absence. The next time a job doesn’t fire, we want to know within minutes, not hours.