Break/Fix: Sampling Removes Important Traces

Scenario

You are operating a production observability platform. The following symptoms appear:

• Error traces are missing

Available evidence:

• Sampling rate is low; rare errors are dropped

Your task

Determine the cause, recover, document, and validate.

Investigation

The investigation follows the discipline taught in Part XCVIII:

1. Form hypothesis, find evidence, test, validate.
2. Use the available evidence above to bound the search.
3. Reach one of the likely root causes.

Recovery procedure

(Do not reveal until you have reasoned through the problem.)

1. Identify the failing component.
2. Apply the remediation pathway.
3. Validate with the verification step.
4. Document the incident.

Remediation

1. Move to tail sampling. 2. Keep all errors. 3. Validate.

Verification

Error traces appear; aggregate rate is bounded.

Rollback

Revert

Prevention

Tail sampling config review