PrometheusAlertmanagerNotificationFailing #

Alertmanager is failing sending notifications

alert: PrometheusAlertmanagerNotificationFailing
annotations:
  description: |-
    Alertmanager is failing sending notifications
      VALUE = {{ $value }}
      LABELS = {{ $labels }}    
  runbook: https://srerun.github.io/prometheus-alerts/runbooks/prometheus-self-monitoring-internal/prometheusalertmanagernotificationfailing/
  summary: Prometheus AlertManager notification failing (instance {{ $labels.instance
    }})
expr: rate(alertmanager_notifications_failed_total[1m]) > 0
for: 0m
labels:
  severity: critical

Meaning #

The PrometheusAlertmanagerNotificationFailing alert is triggered when Alertmanager is experiencing issues sending notifications. This means that critical alerts may not be reaching the intended recipients, potentially leading to delayed or missed responses to incidents.

Impact #

The impact of this alert is high, as it can lead to:

• Delays in responding to critical incidents, potentially causing further damage or downtime
• Missed opportunities to address issues promptly, resulting in longer resolution times
• Inefficient use of resources, as teams may not be notified in a timely manner to address issues

Diagnosis #

To diagnose the issue, follow these steps:

1. Check the Alertmanager logs for errors or warnings related to notification sending
2. Verify that the notification configuration is correct and up-to-date
3. Check the status of the notification channels (e.g., email, PagerDuty, etc.) to ensure they are functioning correctly
4. Review the Alertmanager metrics to identify any trends or patterns that may indicate the cause of the issue

Mitigation #

To mitigate this issue, follow these steps:

1. Restart the Alertmanager service to reset the notification sending mechanism
2. Verify that the notification configuration is correct and up-to-date
3. Check the status of the notification channels and resolve any issues found
4. Implement a temporary workaround, such as manual notification or alternative notification channels, to ensure critical alerts are still being sent
5. Investigate and address any underlying issues that may be causing the notification failures, such as network connectivity problems or authentication issues.
6. Consider implementing redundancy or failover mechanisms for Alertmanager to minimize the impact of notification failures in the future.

Remember to refer to the runbook for more detailed instructions and guidance on resolving this issue.