Break/Fix: TLS Certificate Expired

Scenario

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

• A service is not accepting connections

Available evidence:

• probe_ssl_earliest_cert_expiry shows past date

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. Identify the certificate. 2. Renew. 3. Verify with probe.

Verification

TLS handshake succeeds.

Rollback

Revert

Prevention

Alert at 30 / 7 / 1 day thresholds