Practice
Work an incident, not a tutorial
Every exercise here drops you into a failure and asks what you would do next. The obvious answer is usually wrong, which is the point.
Free · Worksheet
Investigation worksheet
The structure to work any incident. Printable, and useful on its own.
Free · ~25 min · intermediate
Lab: CrashLoopBackOff
A service crash-looping after a routine config change, with logs that show a normal startup and no error anywhere. Work out what is killing it.
Free · ~35 min · expert
Lab: Nova NoValidHost
Instances stopped building on a cloud with visible free capacity. Work the evidence, form hypotheses, and find why the scheduler has no candidates.
Free · ~20 min · intermediate
Lab: Destructive Plan Review
A routine-looking Terraform pull request. Find the changes that would destroy data before you approve it, and work out which one is not what it appears to be.
Pro · ~40 min · advanced
Phantom Capacity Incident
A guided production incident where instance builds fail for lack of capacity on a cloud that is barely a third used. Find the capacity that does not exist.
Pro · ~35 min · advanced
RabbitMQ Partition Incident
A guided production incident where the whole OpenStack control plane reports down while every workload keeps running. Work the evidence and find what is actually wrong.
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