QueueWorkerCritical has paged 42 times in the last hour, although the queue workers report zero lag.
Stage 5 of 5 in Linux Outage Ladder.
That is all the pager knows. The rest is on the box: open a shell, read the signals and work out what changed.
Inspired by a real outage: Log-based alert with an unbounded lookback keeps paging after recovery (FixOps composite of public postmortem patterns). Names and details are fictionalized.
The fix is yours to find: hints, the recovery checks and the debrief unlock inside the incident.
The alert fires and the clock starts. Read the page and the briefing.
Work in a simulated shell with realistic output: logs, configs, services.
Change the system the way you would in production. Hints are there if you get stuck.
Automated checks verify the recovery, then the debrief explains what happened.
Free, instant, and it works on your phone. No signup: start as a guest and save your progress later.