Break/Fix: Alertmanager Delivery Failure

Scenario

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

• Alerts are firing but not reaching the receiver

Available evidence:

• PD / Slack / email status is failing

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. amtool test receiver. 2. Fix the integration credentials. 3. Validate.

Verification

Receiver receives notifications.

Rollback

Revert configuration

Prevention

Alertmanager has alerting on its own health metrics.