Cold exploration reconstructs an unreproducible failure from what remains after it occurs. Instead of watching the error unfold, build a timeline around the initial report and piece together the sequence from logs, metrics, and other traces. section 10.3.2
A practical cold-exploration investigation:
- Establish when the error was first reported. section 10.3.2
- Collect logs, metrics, console output, network traces, monitoring data, recent code changes, and dependency information. section 10.3.2
- Reconstruct the events leading up to the failure, using experience, intuition, and creativity to connect incomplete clues. section 10.3.2
- Form and evaluate hypotheses until the likely root cause is supported by the available evidence. section 10.4
Cold versus hot exploration
A web form failure that can be triggered supports hot exploration: follow the browser error, network trace, and backend logs while the failure unfolds. When the same failure cannot be reproduced, use the remaining logs, metrics, and traces to reconstruct its timeline instead. section 10.3.2
